"Asclepius" C#6

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*Nitrogen (N) (MOBILE)* Macronutrient Nitrogen is an essential nutrient because it is a part of the makeup of all plant and animal proteins. The nutritive value of the food we eat is largely dependent on having an adequate supply of N. Nitrogen is required in greater quantities by crops than any of the other essential nutrients, except potassium (K). Some crops take up more K than N. Table 1 shows how much N is required by a number of common crops. Inorganic nitrate and ammonium are the major forms of N taken up by plant roots. Although the amount of N stored in soil organic matter is large (often more than 1,000 lbs/A), the amount released and available for plant uptake is relatively small. Often, that release is not synchronized with plant demand. Very little N is found in rocks and minerals. Organic matter releases N slowly, the rate being controlled by soil microbial activity (influenced by temperature, moisture, pH, and texture). In general, about 20 to 30 lb N/A are released annually for each 1 percent organic matter contained in the upper 6 to 7 inches of soil. One of the products of organic decomposition (mineralization) is ammonium, which can be held by the soil, taken up by crop plants or converted to nitrate. The nitrate is used by plants, leached out of the root zone, or converted to gaseous N and lost back into the atmosphere. The conceptual relationship between plant-unavailable N (organic matter) and plant-available N (ammonium and nitrate) and soil temperature effects are illustrated in Figures 1 and 2. *Phosphorus (P) (MOBILE)* Macronutrient Phosphorus is present in every living cell, both plant, and animal. No other nutrient can be substituted for it when it is lacking. Phosphorus is one of the 17 essential nutrients that plants need for growth and reproduction. Phosphorus is considered one of the three major nutrients along with nitrogen (N) and potassium (K). They are termed major nutrients because of the relatively large amounts utilized by plants (table 1) and the frequency with which their deficiencies limit plant growth. Phosphorus is a vital component in the process of plants converting the sun’s energy into food, fiber, and oil. Phosphorus plays a key role in photosynthesis, the metabolism of sugars, energy storage and transfer, cell division, cell enlargement, and the transfer of genetic information. Phosphorus promotes healthy root growth, promotes early shoot growth, speeds ground cover for erosion protection, enhances the quality of fruit, vegetable, and grain crops, and is vital to seed formation. Adequate P increases plant water use efficiency, improves the efficiency of other nutrients such as N, contributes to disease resistance in some plants, helps plants cope with cold temperatures and moisture stress, hastens plant maturity, and protects the environment through better plant growth. Plant roots can only acquire P from the soil when it is dissolved in soil water. Since only very low concentrations of P are present in the soil water, P must be continually replenished from soil minerals and organic matter to replace the P taken up by plants. Plant roots generally absorb P as inorganic orthophosphate ions. *Potassium (K) (MOBILE)* Macronutrient Potassium is an essential plant macronutrient taken up in large quantities, like nitrogen. In plants, K does not become part of complex organic molecules. It moves as a free ion and performs many functions. Potassium in Plants In plants, K is involved in many essential functions. It serves to: • regulate water pressure in plant cells, affecting cell extension, gas exchange, and movement of leaves in response to light; • activate enzymes that help chemical reactions take place; • synthesize proteins; • adjust pH within plant cells; • increase carbon dioxide fixation during photosynthesis; • transport chemical compounds; and • balance electrical charges in various parts of cells. Harvesting crops remove K from the soil. The quantity removed varies with the quantity of biomass and K content of the plant organs harvested (table 1). table 1. Potassium uptake and removal rates for selected crops. Plants that are supplied with adequate K are better able to withstand stress, insect damage, and many plant diseases compared with plants low in K. As plants age, rainfall leaches K from plant leaves, depositing K at the soil surface. Plants, therefore, redistribute K from lower depths to the soil surface, a process termed “uplift.” Uplift contributes to nutrient stratification in no-till and reduced tillage systems and affects how soil tests change in response to K additions and crop removal. Plants can only access K when it is dissolved in the soil solution. Contributors to potentially plant-available K are: • K redistributed from other areas, including irrigation water, precipitation, commercial fertilizer, manure, biosolids, and sediment deposition; • weathering of K-containing primary minerals like micas and some feldspars; • K released from the interlayers of the layer silicate minerals illite, vermiculite, and smectite; and • K desorption from surfaces and edges of layer silicate minerals, termed “exchangeable K.” Exchangeable K is measured by soil tests and is considered readily available for plants. Layer silicate minerals that release Selenium K can also “fix” K, or bond K in interlayer positions, thereby removing it from the soil solution. Fixation and release of K by these minerals is dynamic throughout the year. *Boron (B) (IMMOBILE)* Micronutrient Over the past 80 years, hundreds of reports have documented the role of boron (B) in agricultural crops around the world. Responses to fertilization have been documented in almost every state and province in the U.S. and Canada. Alfalfa frequently responds, and so do a large number of fruit, vegetable, and field crops. *Calcium (C) (IMMOBILE)* Macronutrient Calcium is classified as a “secondary nutrient” that is needed in relatively large amounts by plants in the form of Ca 2+. In some species, the requirement for Ca is greater than for the macronutrient phosphorus (P). The critical Ca concentration in plants varies widely, ranging from about 0.2% in grasses, 1.0 to 1.25% in fruit crop foliage, to 2.0% in cotton leaves 1. The amount of Ca taken up by various crops is listed in table 1. Calcium plays a key role in the cell wall structure and membrane integrity. In addition to plant stability, strong cell walls help prevent invasion by numerous fungi and bacteria. Calcium also promotes proper plant cell elongation, participates in enzymatic and hormonal processes, and plays a role in the uptake processes of other nutrients. calcium in Soils The total amount of Ca in soils normally ranges from 0.7 to 1.5% in noncalcareous, temperate soils. Highly weathered tropical soils typically have a lower Ca content, ranging from 0.1 to 0.3%, while calcareous soils may contain as much as 25% Ca. Although there may be tens of thousands of pounds of total Ca/A in the root zone, it is common to have less than 100 lb of Ca actually soluble at any one time. The solubility of Ca depends on several soil factors, including: • Soil pH – soils with higher pH typically contain more available Ca on cation exchange sites • Cation exchange capacity (CEC) – available Ca is affected by both the soil cation exchange capacity and the Ca saturation on the soil cation exchange sites • Presence of other soil cations – Ca is preferentially adsorbed on cation exchange sites. Its solubility and plant availability is influenced by other cations in the soil. Calcium has an important influence on soil properties, especially as it prevents the dispersion of clay. An abundant supply of Ca can help reduce soil crusting and compaction, leading to improved water percolation, and reduced runoff. Calcium is not typically formulated into fertilizer sources specifically to meet plant Ca requirements, but rather as a component of other materials. The most common Ca sources are liming materials, mainly CaCO3. Most acidic soils that have been limed to the proper pH will not have Ca nutritional problems. Calcium is often supplied as gypsum as an amendment to improve soil chemical or physical properties. Clays can disperse in soils with high sodium (Na) content, resulting in poor soil structure and reduced water permeability. Added Ca replaces the Na + on the cation exchange sites and corrects clay dispersion problems. Calcium is a component of several common Nitrogen (N) and P fertilizer materials. *Chloride (Cl) (IMMOBILE)* Micronutrient Chloride is commonly found in nature—from seas, to soils, to the air—it’s everywhere. It is a monovalent anion, having a single negative charge (Cl-). Plants take up the element chlorine in this anionic form. Under standard conditions chlorine (Cl) is an unstable, yellow-green gas. Unlike Cl- , free Cl rarely occurs in nature. Chloride was first generally recognized as a plant nutrient in the mid-1950s. However, its value as a fertilizer supplement was not appreciated until the 1970s when work in the northwestern U.S. and elsewhere showed that some crops may indeed respond to Cl- fertilizer application. Since that time there has been a great deal of work investigating crop response to the addition of Cl-, and determining optimal management practices for Cl- fertilization. Chloride fulfills many important functions in plants. Some of the roles of Cl- in plants are: • Photosynthesis and enzyme activation. Some of the enzymes activated are involved in starch utilization which affects germination and energy transfer. • Transport of other nutrients. Chloride aids in the transport of nutrients such as potassium (K +), calcium (Ca2+), and magnesium (Mg2+) since it acts as a counterion to maintain electrical balance. • Water movement in cells. Cellular Cl- helps water move into cells and also aids in water retention in cells, thereby impacting cell hydration and turgor. • Stomatal activity. Both K and Cl- are involved in the movement of guard cells that control the opening and closing of leaf pores or stomata. • Accelerated plant development. Adequate Cl- in small grain production results in earlier head formation and emergence than where Cl- is deficient. In winter wheat production maturity advances of 5 to 7 days have been observed. • Reduced lodging. Chloride strengthens stems, helping to reduce lodging later in the season. Among the most notable impacts of Cl- is its role in reducing the effects of numerous plant diseases. This effect may be related to its function in osmotic regulation. In wheat, Cl- has been shown to suppress take-all root rot, tan spot, stripe rust, leaf rust, and Septoria, while in corn and grain sorghum it has been shown to suppress stalk rot. Nearly all Cl - in soils exists in soil solution. Chloride, like nitrate (NO3-), is mobile in soils and moves freely with soil water. Thus, under certain conditions it can be readily leached from the root zone. There are several potential sources of Cl- in crop production systems, including rainfall, marine aerosols, volcanic emissions, irrigation water, and fertilizer. Some irrigation water contains substantial amounts of Cl - often enough to meet or exceed crop needs. Atmospheric deposition can be particularly high in coastal areas. But regions further inland, such as the Great Plains of the U.S., have much lower atmospheric deposition of Cl - making the likelihood of response to Cl- fertilizer higher. Where there is a history of Cl containing fertilizer application (such as muriate of potash; also known as MOP, potassium chloride or KCl) it is not likely that Cl- will be limiting for crops. *Cobalt (IMMOBILE)* Micronutrient Cobalt (Co) fertilization is occasionally reported to benefit crop growth, but the need for supplemental Co is rather rare. Cobalt has only recently been recognized as a potentially essential nutrient for plants. Cobalt is necessary for nitrogen (N) fixation occurring within the nodules of legume plants. *Copper (Cu) (IMMOBILE)* Micronutrient Copper is one of eight essential plant micronutrients. When Cu is deficient, common crop responses to its application include reduced disease, increased crop growth and improved quality. Commonly applied Cu sources include fertilizer, animal manures, biosolids, and pesticides. *Iron (Fe) (IMMOBILE)* Micronutrient Iron is a component of many vital plant enzymes and is required for a wide range of biological functions. Most soils contain abundant Fe, but in forms that are low in solubility and sometimes not readily available for plant uptake. *Magnesium (Mg) (MOBILE)* Macronutrient Magnesium is one of nine macronutrients and is taken up by plants in quantities similar to that of phosphorus (P). In plants, Mg is essential for many functions. It: • sets in motion (catalyzes) the production of chlorophyll and serves as the central atom in the chlorophyll molecule; • serves as a building block of ribosomes, the “factories” that synthesize proteins in cells; • stabilizes certain structures of nucleic acids, the molecules that transfer genetic information when new cells are formed; • activates or promotes the activity of enzymes, which are molecules that have specific shapes needed to set in motion certain chemical reactions necessary for proper growth and development of plants; • serves as an essential element to create adenosine triphosphate (ATP), the “battery” that stores energy in the plant; • ensures carbohydrates created in leaves are exported to other plant organs. Carbohydrates are used in plants for energy and for structure. Plants can only access Mg in the soil solution. Contributors to this Mg are: • redistribution from other areas, including: irrigation water, commercial fertilizer, manure, biosolids, and sediment deposition; • weathering of Mg-containing primary and secondary minerals like certain types of amphiboles, biotite, chlorites, dolomite, garnets, olivine, magnesite, phlogopite, some pyroxenes,serpentines, talc, and tourmaline; • release from the interlayers of the layer silicate minerals chlorite, smectites, and vermiculite; and • release (desorption) from surfaces and edges of layer silicate minerals, termed “exchangeable Mg.” Exchangeable Mg and Mg in the soil solution are the Mg forms measured by soil tests and are considered readily available to plants. Minerals containing Mg are more soluble in acid soils (below pH 7). In sandy soils with low numbers of exchange sites (location exchange capacity), dissolved Mg can move below the root zone because there are not enough edges and surfaces of layer silicate minerals to retain it in the upper levels of the soil. Therefore, levels of exchangeable Mg in acid, sandy soils can be too low to meet plant nutritional needs. When plant roots take up water, more water from farther away moves to the roots to replace that which was taken up. Magnesium that is dissolved in the soil solution moves with this water. This process, termed mass flow, is responsible for keeping the plant supplied with dissolved Mg. *Manganese (Mn) (IMMOBILE)* Micronutrient Manganese is one of the 17 elements essential for plant growth and reproduction. It is needed in only small quantities by plants, but like other micronutrients, Mn is ultimately as critical to plant growth as the major nutrients. *Molybdenum (Mo) (IMMOBILE)* Micronutrient Molybdenum is a trace element required in very small amounts for the growth of both plants and animals. Crop deficiencies of Mo are fairly uncommon, but there are a variety of soil and foliar fertilizers that can be used to correct this condition when it occurs. *Nickel (Ni) (IMMOBILE)* Micronutrient Nickel is the most recent element to be added to the list of essential plant nutrients. *Selenium (Se) (IMMOBILE)* Micronutrient Selenium is not essential for plants but is required for many physiological functions in humans and animals. Since Se is obtained primarily from food, its accumulation by plants impacts human health. *Silicon (Si) (IMMOBILE)* Micronutrient Silicon is generally not considered an essential element for plant growth. However, due to its important role in plant nutrition, particularly under stressful conditions, it is now recognized as a “beneficial substance” or “quasi-essential.” *Sulfur (S) (IMMOBILE)* Macronutrient Sulfur is used by plants in sufficient quantities that it is considered the fourth most needed fertilizer nutrient after the three macronutrients nitrogen (N), phosphorus (P), and potassium (K). Sulfur fertilization is increasingly common because higher-yielding crops are taking up and removing more S from the soil as harvested products. Due to a decrease in S emissions from industrial and transportation sources, S deposition from the atmosphere is much lower than a few decades ago. Maintaining an adequate supply of S is essential for sustaining high-yielding crops, as well as for animal and human nutrition. Soluble sulfate (SO 42- ) is the primary source of S nutrition for plants. Within the plant, S is required for protein synthesis. It aids in seed production and produces the chlorophyll necessary for plants to carry out photosynthesis. It is a necessary component of three amino acids (cysteine, methionine, and cystine) needed for protein synthesis. It is also required for nodule formation on root hairs of legume crops. Wheat grown in soils with low levels of available S result in lower-quality of grain protein, making the flour less suitable for bread making. Since both S and N are needed for protein formation, these two nutrients are closely linked. Crops have varied requirements for S compared with N and have a wide N:S ratio in the harvested product (table 1). For example wheat has a relatively low requirement of S, with an N:S ratio in a grain of 16:1. Canola has a high S requirement, with an N:S ratio of 6:1 in the seed. Sulfur is involved in a number of secondary plant compounds. For example, the characteristic flavor and smell of onions and garlic are associated with volatile S compounds. plant roots take it up. Common soil bacteria (e.g. Thiobacillus species) are responsible for converting elemental S to sulfate, but this process can take from weeks to years. Favorable conditions of soil temperature, moisture, pH, and aeration will speed this conversion to sulfate. Similarly, a small particle size of elemental S will enhance the rate of conversion. *Zinc (Zn) (IMMOBILE)* Micronutrient Zinc is a trace element and only required in very small amounts in the plant, Zn deficiency in crops is widespread around the world. Low Zn content in food crops contributes to Zn deficiency in approximately 30% of human diets. With the world population continuing to expand, it is critical that attention be paid to Zn nutrition in food crop production. *Acidity and Alkalinity* All the carefully applied homemade fertilizer in the world won't help plants that are not in their optimal pH range. If the soil is too acid or alkaline for the plant, it shuts down the plant's ability to access sufficient nutrients. In addition to fertilizing, check the pH to be sure your efforts aren't in vain. Increase acidity with vinegar and use wood ash to increase alkalinity. If these ingredients are used to provide a nutrient, be sure they are in balance with the pH needs of the plant.

100-gallon Fabric pot fitted with 15w air intake, that gives me an idea.

Some companion plants to keep her company until last frost. She is bushy and compact with a strong hard stem, can already see her purple hue 😍. Just playing the waiting game I'm in no hurry with this one 🕜. Getting 6 hours of 280-380nm daily. (Measure it lazy ass)

Really love a set of scales to keep track of weight too. pH and EC are both critical for thriving plant health, but temperature also plays a pivotal role in achieving optimal growth. It also happens to be the fundamental parameter that's most commonly overlooked. When you think about temperature in the context of a growing environment, you could be referring to the temperature of the air around the plants or you could also be referring to the temperature of nutrient solution or irrigation water, which will affect the root zone temperature. While air temperature is important, for the purposes of this piece, I'll be focusing on root zone temperature and its effect on nutrient uptake and overall plant health. That's because a plant's root system is the location of two essential chemical processes: water and nutrient absorption. In each of these processes, having the correct root zone temperature is paramount for these to occur efficiently. In a nutshell, root zone temperature will affect the rate at which your plants are able to absorb nutrients. If you let your root zone temperature remain unmonitored and uncontrolled, this could lead to disastrous effects on your overall crop yield. Nutrient absorption is largely driven by chemical processes, which take place in your plants' roots; the efficacy of these processes is determined by the temperatures to which those roots are exposed. Once your root zone temperature moves out of its optimal range, the plant will not be able to deliver optimal levels of nutrients and water. Ideally, you should aim to have your nutrient solution or irrigation water temperature at around 18 – 22 °C (65 - 72 °F) to ensure optimal nutrient and water uptake. In addition to having an effect on nutrient absorption, your root zone temperature also affects oxygen availability and solubility. If your water is too warm, you could risk starving your roots of oxygen as warm water cannot hold as much dissolved oxygen as colder water. On the other hand, if your water is too cold, this could shock your plant roots, decrease plant metabolic rates, and stunt plant growth. Peace out.

The plant realizes there is an overabundance of light and it seems to understand this and develops accordingly. I see a mass monster. Focused on rates of photosynthesis, instead of photomorphogenesis. Added a custom Lakhovsky ring around the base. It is positioned in such a way that it rotates on itself, as in the photo, and an energy field will develop all around. If we have only 1 ring, the opening goes true north and the 2 wires must not touch. With 2 rings of different diameters, I can alternate North / South openings. (4x10" Copper wire wrapped in aluminum sheathing then further coil wrapped with copper)

One massive bud. Getting impossible to see inside, have no idea what this plant looks like under there, pull one branch aside two more pop up, not sure, that's a lot of light for one plant to consume, aloooot. Twice now I have forgotten to turn back on the electric current after watering!! Both times it was distinctively noticeable, the 2nd time I noticed by sight alone. Should really be conducting the test with a genetic twin unelectrified, would need to be done separately from the magnetic & electric fields within the tent, regardless, fascinating to watch. Lets fire her up.

Screw the stretch then. Full spectrum lighting from the top, the blue & red emitting from the "full spectrum" light only penetrates 1-2 layers of the leaf, the green wavelength will penetrate 4,5,6 layers, and the best ratio for flower growth is 1/2/1 R/B/G, and very little of the red and blue reaching lower parts of the plants or even the sides, flowers on lower parts of canopy receiving a majority of green will grow larf style buds, often lackluster, I supplement blue and red at the sides, I do not want to add more "full spectrum" this would double dose the green which penetrates deep. By the end of week, I'm looking at bud sites everywhere, the density is exceptional and above what i'm come to expect in week 1.5, it was the like plant skipped the stretch and went right to bud site production.

Defoliating

Added 4 new lights Figure 1. Photomorphogenesis as a morphological and as a cellular process. The left photos show the change in form of an Arabidopsis thaliana seedling grown in darkness (top) or in white light. The right hand illustration shows the change in chloroplast structure and diagrams the progress of light signals through two receptor systems, cryptochrome and phytochrome. Adapted from Biochemistry and Molecular Biology of Plants, (c) American Society of Plant Biologists, with permission. Figure 2. A sunfleck in a patch of Oxalis oregana. A gap in the shade exposes this forest floor herb to full sunlight. The fleck will move across the plants as the sun moves, causing the plants to experience two widely different light environments on a short time scale (minutes). Photograph courtesy of Dr. Olle Bjorkman. Figure 3. Diagram of interconversion of the Pr and Pfr forms of phytochrome. Figure 4. Absorption spectra for the 2 forms of phytochrome shown in figure 3. Adapted from Biochemistry and Molecular Biology of Plants, (c) American Society of Plant Biologists, with permission. Big sessile organisms like plants and fungi and small organisms whose motility can't move them that far, like bacteria and protists, have no option but to function in the environment they are found in. For photosynthetic organisms it has been adaptive for them to develop mechanisms to sense their light environment, and adjust their form and metabolism to optimize their performance under their local conditions. Since light environments change, these organisms have also developed the ability to continuously adjust their function to current conditions. Taken together these responses to light constitute the phenomenon known as photomorphogenesis. The definition of photomorphogenesis, as applied in this module, is any change in form or function of an organism occurring in response to changes in the light environment. Photomorphogenesis is often defined as light-regulated plant development (Figure 1), but there are also changes in morphology and/or cell structure and function, which occur as transient acclimatizations to a changing environment, which are also light regulated. Particularly if this more inclusive definition is used, photomorphogenesis is a process common to organisms well beyond the plant kingdom. While there may be only a few examples of photomorphogenesis in the animal kingdom, it is a common feature of development in fungi, protists, and bacteria, as well as plants. While this module will focus on what is known from studies of plant photomorphogenesis, there will be selected examples from other kingdoms. many developmental events at the cellular and (where relevant) organism level. Table 1 The changes in the light environment occur across a wide range of time scales. For example, the direction of light coming from a gap in a forest canopy can be constant over days to years, while the direction of the sun in an open field changes from moment to moment. The sunfleck (Figure 2), a transient gap in a forest canopy caused by a momentary opening of a path for full sunlight to pass through the branches and leaves, is an example of a rapid change in light intensity. Other changes in light intensity occur on daily and yearly time scales. For plants, spectral quality is controlled by shading and scattering by neighboring plants, and these effects change relatively slowly, with the exception of tree falls causing canopy gaps. For aquatic organisms such as photosynthetic bacteria, algae and protists, the spectral quality of light changes with the position of the organism in the water column, and the presence of other organisms higher within that column. Both of these factors can change rapidly and unpredictably. [Further information about terrestrial and aquatic light environments can be found in the PSO Modules on environmental biology. chromophores (one of 3 bilitrienes similar to a heme; (Burgie and Vierstra 2014)), and share other aspects of structure, function and signal transduction. Phytochromes are the dominant contributors to the sensing of light quality in plants, and also participate in the sensing of light presence, intensity and duration, and to a lesser extent light direction. The blue light sensors are a diverse group of molecules performing similar functions in different contexts (Lin, 2002), so instead of a family of related molecules they more closely correspond to a guild. Some blue light responses can be induced by both blue and UV-A light, while others are responsive to only blue light. Different photomorphogenic responses to the same spectral region exhibit action spectra with different peaks and fine structure. Two distinct guild members use flavin/pterrin chromophores, while a third sensor is a carotenoid. One sensor functions principally in phototropism, another in sensing light quality and duration, and a third, light intensity in specific cells. These photoreceptors have been identified in seed plants by a combination of genetic and biochemical studies. There are responses in protists, fungi, green algae and ferns that exhibit a similar action spectra to the seed plant responses, but for which the identity of the photoreceptor has not been as rigorously established. The Phytochrome Photoreceptors The phytochrome family of photoreceptors has an unusual feature that was a significant advantage in the study of the phytochrome regulation of photomorphogenesis, and the purification and characterization of the photoreceptor itself. The chromophore for phytochrome is photochromic, i.e., it undergoes a change in conformation that makes a stable change in its light absorption properties. When the chromophore is in one state, the phytochrome molecule is inactive, and when it is in the other state the phytochrome molecule initiates what are to this point poorly understood signaling processes. Phytochromes are synthesized in the inactive form, for which the absorption maximum is 660 nm. The red absorbing form, Pr, on absorption of a photon, converts to a form with an absorption maximum of 730 nm, Pfr (far red). The Pfr from is the active form, but it can be converted back to Pr (and inactivated) by the absorption of a far-red photon (Figures 3 and 4). sensitivity to light allows this process to begin even before the seedling breaks through the soil. (see Awakened by a Flash of Sunlight). There is nothing special about the efficiency of photon absorption by phytochrome, but plants produce one form of the molecule (the A-type phytochrome; see below) at extremely high levels, and it takes only a very small percentage of this population being converted to the Pr form to begin de-etiolation. This is the response described in the introduction as a response to the simple presence of light. The Phytochrome Gene Family It was something of a surprise when it was found that plants possess at least 5 different phytochromes coded for by separate genes. The phytochromes have been given the letter designations A-E, and specific roles for some of the phytochromes have been identified. The A-type phytochrome is the species produced in high abundance in seedlings to provide the "early warning" signal for de-etiolation described above. However, this has turned out to be one of few cases where the responsibility for a specific photomorphogenic process can be unambiguously ascribed to just one type of phytochrome. Sorting Out The Phytochromes, and The Types Of Responses They Control* Physiological evidence first revealed that the stability of phytochromes Physiological evidence first revealed that the stability of phytochromes differed in dark and light-grown tissues. Along with other evidence, this indicated the existence of two pools of Pfr, a labile pool and a stable pool; pools that have since been found to represent different molecular species of phytochromes. Evidence of distinct types of phytochromes has been provided by the cloning and sequencing of five genes from Arabidopsis (designated PHYA through PHYE) that encode phytochromes A through E. The amino acid sequences of PHYA, PHYB, and PHYC are equally divergent and demonstrate about 50% homology to each other. Mutant analysis has revealed some of the separate functions performed by the various phytochromes. The cucumber lh mutant and the Arabidopsis hy3 mutant, which grow taller than wild-type plants in white light, are deficient in PHYB. The aurea mutant of tomato is deficient in PHYA, and has been used to dissect the phytochrome response. A recent mutant screen has identified PHYC mutants in Arabidopsis, and phenotypic analysis of a PHYD mutant in one Arabidopsis ecotype indicates that PHYD regulates several of the same responses as PHYB. Phytochrome responses can be characterized by both the amount of light required to activate them. The Box Figure (below) illustrates the separation of phytochrome responses into 3 types based on the quantity and duration of the light treatment needed to induce them. The two responses labeled VLF (Very Low Fluence) and LF (Low Fluence) are described as "induction" responses to indicate that they are induced by a short pulse of light, following which plants/seeds can be returned to darkness. Common induction responses include seed germination seedling stem elongation. The VLF response can be activated by short pulses of very weak light. A rough calculation was made that a VLF response can be induced by 1-3 firefly flashes. The LF response is the classical low fluence red/far-red reversible phenomenon. At first it might seem a surprise that the VLF response does not show the photoreversibility normally associated with phytochrome mediated responses, but this can be understood once it is appreciated just how few molecules of Pfr are needed, so few that even far-red light produces enough (Note overlapping absorption spectra in Figure 4). Mutational investigations on seedlings deficient in phytochromes clearly implicate PHYA as the regulator. Mutational studies have implicated PHYB as the prime regulator of LF response. The high irradiance reaction (HIR) requires continuous or prolonged irradiation with high-intensity light. The response in this case is proportional to the irradiance received by the plant; again, photoreversibility is absent. Typical HIR responses are anthocyanin synthesis or inhibition of hypocotyl elongation. Although phytochromes clearly are involved in these responses, evidence indicates that other photoreceptors that absorb UV or blue light contribute to this control. *adapted from Biochemistry and Molecular Biology of Plants, (c) American Society of Plant Biologists, with permission. A powerful but labor intensive experimental approach to identifying the roles of the individual phytochromes has been the creation of mutations in each of the phytochromes, then crossing individuals with single mutations to create plants with progressively fewer and fewer functional phytochromes. This is discussed in detail in the module on Photoreceptor Mutants. The results of these studies have revealed that there are significant redundancies among the roles for each phytochrome, and even that the regulatory effects of one phytochrome can be in the opposite direction from those of another member of the family (Josse et al., 2008). Redundancies and cross-talk with the cryptochrome family of blue light receptors (see below) have also been found. A major surprise has emerged as the complete sequences of a variety of bacterial genomes became available. Genes with significant homology to the plant phytochrome genes were found in several species. This was not so surprising in the case of the cyanobacteria. The sensing of differences in light spectral quality involved in complementary chromatic adaptation has points in common with sensing of shade in plants. However, finding that there are sequence similarities suggesting a common evolutionary origin of the procaryotic and eucaryotic photosensors was unexpected. More unexpected was the discovery of a phytochrome like gene and corresponding protein in the non-photosynthetic bacterium, Deinococcus radiodurans, followed by a raft of other diverse bacteria (Hughes and Lamparter, 1999). A significant benefit of these discoveries has been that the similarities and differences between the procaryotic and eucaryotic proteins have contributed to understanding how changes in the phytochrome molecule are recognized and converted into responses. Another dimension to making sense of the diversity of responses mediated by multiple phytochrmomes has been the discovery of a family of proteins that interact with phytochrome proteins to transduce responses: the Phytochrome Interacting Factors (PIFs). Eight or more of these proteins make up a family of transcription factors that interact exclusively with the Pfr form of phytochormomes (Leviar and Monte 2014). PIFs are themselves part of a broader network of transcription factors that influence responses to multiple environmental signals. Blue Light Receptors I - Cryptochromes None of the blue light regulated responses exhibit the photoreversibility seen in the phytochrome system. It has turned out that none of the blue light photoreceptors found thus far are photochromic, and this has meant that their identification has been more difficult. The cryptochromes were the first blue light sensors characterized, and their discovery was based on the screening of mutant Arabidopsis plants for defects in photomorphogenesis in response to blue light. When the DNA sequence for cryptochrome 1 was obtained, it was found that there was significant homology to another class of light absorbing protein, the DNA photolyases involved in DNA repair (see module on Photoreactivation). Both cryptochromes and photolyases have the same pair of chromophores, a pterin/deazaflavin and flavine adenine dinucleotide, but the chemistry that occurs after light absorption is quite different. The absorption spectrum of cryptochrome corresponds to the action spectrum of one class of blue light mediated photomorphogenic responses. Cryptochromes mediate blue-light responsive components of de-etiolation, most of which require relatively high intensities of light. Hence they act as sensors of both light quality and light intensity. When plants with defects in both cryptochromes and phytochromes are created by genetic crosses, the results indicate both overlaps and coordination of regulation of de-etiolation by these two systems. The cryptochromes are not the primary sensors for light direction in phototropic responses (see the section on Phototropins, below), but they may modulate these responses. Cryptochrome 2 is also involved in the photoperiodic regulation of flowering, and thus is a sensor for light duration. The involvement of cryptochrome in circadian rhythms extends all the way to the animal kingdom. A protein with DNA sequence homology to the cryptochromes has been found to act as a photosensor in the Drosophila circadian clock, and another protein with homology to cryptochrome has been found to be a signaling intermediate in the mouse circadian system. Blue Light Photoreceptors II - Phototropins Like the cryptochromes, the phototropins were discovered by screening for non-responsive mutants, this time for differential growth towards a unidirectional light source (Briggs and Christie, 2002). For an account of how light direction can be sensed using plant tissue optics, see Blue-Light Sensing and Light Gradients, and the PSO Module on Blue Light Sensing in Plants. One of the genes that, when mutated, conferred a non-phototropic phenotype has been identified as the light sensor phototropin. The protein product of this gene has two flavin mononucleotide chromophores. The absorption spectrum for phototropin is consistent with the action spectrum for phototropism, and the molecule has been shown to be differentially activated in parallel with the light gradient created across a stem irradiated from one side. After the first phototropin (phototropin 1) was identified as the sensor for phototropism, a second phototropin was found, and it appears to regulate phototropic responses to high light intensities and chloroplast movements. Phototropin 2 mediates both the accumulation of chloroplasts to optimize light absorption under low light intensities, and movements to minimize light interception under high light intensities. Like the phytochrome and cryptochrome systems, it turned out that there is redundancy between the two phototropins, and phototropin 1 will replace phototropin 2 in the chloroplast accumulation response, but not the chloroplast avoidance response. This chloroplast movement response is difficult to classify in the general scheme of photomorphogenesis. The chloroplasts can be seen as exhibiting phototaxis, and hence the response is a response to light direction (and hence is also discussed in the module on Basic Photomovement), while from the organismal point of view the response is an optimization of photosynthesis in response to changing light intensity. Both phototropins are also regulators of the very rapid (2-5 min lag time) inhibition of stem elongation in dicots. This growth response is independent from the differential growth that occurs in phototropism, and involves changes in membrane potential and calcium fluxes as intermediates. Blue Light Receptors III - Specialized And Orphan Responses The availability of mutants defective in both the cryptochromes and phototropins led to the discovery that the blue-light regulation of stomatal aperture (see the module on Basic Photosynthesis) was mediated by neither the cryptochromes nor the phototropins. However, a specific mutation in carotenoid biosynthesis does cause a loss of blue light regulation. The formation of the xanthophyll zeaxanthin correlates with stomatal aperture, and the action spectrum for the reaction driving the synthesis of this carotenoid matches the action spectrum for blue light induced stomatal opening (Folta and Maruhnich, 2007; see also the module on Basic Photomovement, and the essay, The Blue-Green Reversibility of the Blue-Light Response of Stomata ). Likewise there is an action spectrum for the folding of the leaf base in Oxalis in response to high intensity blue light (a light avoidance response for a forest floor plant), but it does not match any known photoreceptor. This response has properties in common with the solar tracking movements described at the beginning of this module. In both of these cases, there are no mutants readily available to investigate whether these responses are regulated by any of the known photoreceptors. Responses To Ultraviolet-B Light There are a constellation of plant adaptations to UV-B light, and there is ample documentation that these responses are signaling mediated rather than caused by non-specific damage (Jansen et al., 1998; see also the module on Ultraviolet Effects on Phytoplantkton). Some of these responses have action spectra that implicate a specific receptor. This receptor has recently been identified as the protein coded for by the Ultraviolet Resistance gene 8 (UVR8: see Photomorphogenic Responses of Plants to UV-B Radiation, and Jenkins (2014). UVR8 has been found to mediate UV-B induced photomorphogeneis including modulation of biosynthetic pathways, photosynthetic performance, morphogenesis, and responses to pathogens principally in mature light-grown plants. UVR8 is almost certainly not the only photoreceptor for UV-B radiation. Evidence indicates UVR8 does not to regulate responses in dark-grown Arabidopsis seedlings (Gardner et. al 2011). Other responses to UVB have action spectra that correspond to the action spectrum for DNA damage. These latter responses retain characteristics of photomorphogenic developmental programs. Given that studies of DNA repair have now provided ample evidence that there are signal transduction pathways activated by DNA lesions (McGowan and Russell, 2004), it is not unreasonable to consider DNA as a possible photoreceptor. Indeed, Biever et al. (2014) have provided evidence that thymidine dimer formation is an essential step in the regulation of hypocotyl growth in dark grown seedlings. Responses To Green Light In the last decade it has been found that green light has effects that cannot be accounted for based on the known photoreceptors (Folta and Maruhnich, 2007). In particular, there are effects on early hypocotyl elongation and the closing of the pinnules of compound leaves in Albizzia julibrissin. There are also green light-induced changes in mRNA transcripts found in developing plastids. Other green light effects, such as stomatal closure, have been traced to the carotenoid system described above. Cryptochromes mediate green light effects on flowering time, and by an as yet unknown mechanism, phototropins transduce phototropic responses to green light. If Chlorophyte (Green) Algae Count as Plants, There are Opsins to Consider A flurry of activity has occurred as new opsin type photoreceptors have been found in a variety of unicellular algae. Rhodopsin mediated responses in unicellular algae such as Chlamydomonas have been known for some time (Harz and Hegemann, 1991). Unlike most animal rhodopsins, these photoreceptors function as independent ion channels. Discoveries of new channel rhodopsins have fueled the development of tools in the field of optogenetics, particularly relevant to manipulating electrical signaling in neurons (Fenno et al., 2011). The recent discovery of anion channel rhodopsins (Govorunova et al. 2015) has added new tools, but also indicated that there are yet more photosensors to be discovered. The Future There are clearly a wide range of photomorphogenic responses, such as blue light induced leaf movements, several responses to green light, and an important fraction of responses to UV-B where the photoreceptor carrying out the conversion of a light signal into biological information is not known. Equally important, for none of the photoreceptors identified is it clear how the event of photoreception is transduced into a biological response, or even who the immediate signal transduction partners/targets of the photoreceptors are. The basic science inquiries are underway to obtain this information. There are also practical applications of the knowledge of the action of photoreceptors on developmental processes throughout the life of the plant. Very few plants if any evolved to grow in the light environment of a densely planted field, monoculture or otherwise. The normal photomorphogenic responses to these conditions lead to growth forms that are not necessarily the most productive. For example, dense stands of grasses will produce a light environment with high levels of far red light. This environment stimulates shade avoidance responses, which cause grasses to grow over tall, and "lodge" or collapse onto each other. The selection of cultivars with limited shade avoidance responses could ameliorate this problem. Therefore, it appears possible that modification of innate photomorphogenic programs, either by conventional breeding, or by the creation of transgenic plants, may create growth forms better suited to the needs and limitations of agricultural practice. Another practical application is the aforementioned area of optogenetics. Each of the photoreceptors cataloged here has unique properties that may suit that protein to a particular application. Hence new basic research discoveries could come as fast as solutions to agricultural challenges. REFERENCES Ballaré CL, Scopel AL, Jordan ET, Vierstra RD. (1994) Signaling among neighboring plants and the development of size inequalities in plant populations. Proc. Nat. Acad Sci USA 91: 10094-8 Biever JJ, Brinkman D Gardner G (2014) UV-B inhibition of hypocotyl growth in etiolated Arabidopsis thaliana seedlings is a consequence of cell cycle arrest initiated by photodimer accumulation. J. Exp. Bot. 65: 11 2949-2961. Briggs WR, Christie JM. (2002) Phototropins 1 and 2: versatile plant blue-light receptors. Trends in Plant Science 7:204-210. Burgie, ES, Vierstra RD (2014) Phytochromes: An Atomic Perspective on Photoactivation and Signaling. The Plant Cell 26, 4568-4583. Darwin C, Darwin F. (1880) The Power of Movement in Plants. Appleton and Company, New York. Devlin PF, Christie JM, Terry MJ. (2007) Many hands make light work. J. Exp. Bot. 58: 3071-3077. [ Reprint ] Fenno L, Yizhar O, Deisseroth K (2011) The Development and Application of Optogentics. Ann. Rev. Neurosci. 34: 389-412. Folta KM, Maruhnich SA. (2007) Green light: a signal to slow down or stop. J. Exp. Bot. 58:3099-3111. [ Reprint ] Franklin KA, Larner, JS, Whitelam GC (2005) The signal transducing photoreceptors of plants. Int. J. Dev. Biol. 49: 653-664. Govorunova, EG Sineschchekov OA, Janz R, X Liu Spudich JL (2015) Natural light-gated anion channels: A family of microbial rhodopsins for advanced optogenetics. Science 349: 647-650. Hangarter, R (2000) Plants in motion. Retrieved October 28, 2008. [ Web Site ] Harz H, Hegemann P (1991) Rhodopsin-regulated calcium currents in Chlamydomonas, Nature 351: 489. Hughes, J., and Lamparter, T. (1999) Prokaryotes and phytochrome: The connection to chromophores and signaling. Plant Physiol. 121:1059-1068 [ Reprint ] Jansen MAK, Gaba V, Greenberg BM (1998) Higher plants and UV-B radiation: balancing damage, repair and acclimation. Trends Plant Sci 3:131-135 Jenkins GI (2014) The UV-B Photoreceptor UVR8: From Structure to Physiology. The Plant Cell, 26: 21-37. Josse E-M, Foreman J, Halliday KJ (2008) Paths through the phytochrome network. Plant Cell Env. 31: 667-678. [ Reprint ] Koller D (1990) Light-driven leaf movements. Plant Cell Env. 13:615-632. [Reprint ] Leviar P, Monte E (2014) PIFs: Systems Integrators in Plant Development. The Plant Cell 26: 56-78. Lin C (2002) Blue light receptors and signal transduction. The Plant Cell 14:S207-S225. [ Reprint ] McGowan CH, Russell P (2004) The DNA damage response: sensing and signaling. Curr Opin Cell Biol. 16:629-33.

After all that defoliation, Trichomes look to be ramping up, got my first smell after disturbing a few nugs, was very strong and pungent, far more citrus than I'd expect from a GDP, going to keep temps at a daytime high of 77 for now and hold off on any attempt to color. Preservation of that beautiful smell! Normally this is the point where I would keep up temps to around 84 to utilize a little of the co2 available pushing photosynthesis. But I just can't ignore how much better it smells keeping it to 77 max, last couple grows I feel I have been pushing the temps a bit more been unable to recreate the ultra strong smell of chapter 3, as the plant goes into full trichome production mode I shall start lowering temps again. Still too early though as bud growth seems to be on a roll, multiplying overnight. Keeping night temps within a 10-degree bracket of daytime temps. In the picture I called "THIS ONE" observe the edges of the sugar leave that has taken damage from the UV, it purples the tips, and it looks as if it's been cured it's hard to describe, none the less trichomes keep layering on top of one another on these spots, I had noticed it on previous grow too, just keeps piling on the fluorescent patch until you get these dense little clusters Truthfully don't think these will purple this time round, we will see

When the DNA sequence for cryptochrome 1 was obtained, it was found that there was significant homology to another class of light-absorbing protein, the DNA photolyases involved in DNA repair and the process of photoreactivation. Photolyases are DNA repair enzymes that repair damage caused by exposure to ultraviolet light. These enzymes require visible light both for their own activation and for the actual DNA repair. The DNA repair mechanism involving photolyases is called photoreactivation. Enzymes are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. UVR8 has been found to mediate UV-B-induced photomorphogenesis including modulation of biosynthetic pathways, photosynthetic performance, morphogenesis, and responses to pathogens principally in mature light-grown plants. Given that studies of DNA repair have now provided ample evidence that there are signal transduction pathways activated by DNA lesions, it is not unreasonable to consider DNA itself as a possible photoreceptor. In just a few seconds, ultraviolet light from the sun can damage DNA by creating hundreds of unwanted links within DNA's double helix. These modifications make the genetic material bulky and unreadable by DNA replication tools, leading to permanent mutations that can cause cancer and other diseases if left unrepaired. Photolyases belong to the cryptochrome/photolyase protein family (CPF) which perform different functions such as DNA repair, circadian photoreceptor, and transcriptional regulation. Photolyase is a flavoprotein that repairs UV-induced DNA damages of cyclobutane pyrimidine dimer (CPD) and pyrimidine-pyrimidone (6-4) photoproducts using blue-light as an energy source. This enzyme has two chromophores: flavin adenine dinucleotide (FAD) as a cofactor and a photo antenna such as methyltetrahydrofolate (MTHF). The FAD is essential for catalysis of the DNA repair. The second chromophore absorbs photons from the blue light spectrum and transfers energy to FAD to increase the repair efficiency of the enzyme. UV-B resistance 8 (UVR8) also known as ultraviolet-B receptor UVR8 is a UV-B – sensing protein found in plants and possibly other sources. It is responsible for sensing ultraviolet light in the range 280-315 nm and initiating the plant stress response. 90+% activated at 285nm

The very strong smell permeates throughout the house, love it, free air freshener. Not smelling any lavender so far, right now it smells .... Very citrusy, almost like White Widow when I disturb the nugs. Reduced dosage of UV to 6 hours Did you know? People often call simple carbohydrates "sugars". In plants, the opposite of photosynthesis is cellular respiration. Cellular respiration is a series of chemical reactions. They convert glucose back into water, carbon dioxide, and energy. This energy is used for basic metabolic processes as well as growth. Different cell organelles are responsible for photosynthesis and respiration. Photosynthesis takes place inside chloroplasts. Respiration takes place inside mitochondria. Light Factors Affecting Photosynthesis Organisms that can photosynthesize are a very important part of all ecosystems. Photosynthesis is a chemical process in green plants. In it, light energy is converted into chemical energy. Plants use energy from light to combine water (H2O) and carbon dioxide (CO2). The products of this reaction are simple carbohydrates and oxygen (O2). An example of a simple carbohydrate is glucose. In plants, the opposite of photosynthesis is cellular respiration. Cellular respiration is a series of chemical reactions. They convert glucose back into water, carbon dioxide, and energy. This energy is used for basic metabolic processes as well as growth. Different cell organelles are responsible for photosynthesis and respiration. Photosynthesis takes place inside chloroplasts. Respiration takes place inside mitochondria. Organelles and processes involved in cellular respiration and photosynthesis. Both photosynthesis and cellular respiration occur within plant cells. During the day, photosynthesis is the dominant process. At night, or in the absence of light, photosynthesis in plants stops. This is when cellular respiration becomes the dominant process. For a green plant to survive, grow, and reproduce, the rate of photosynthesis must be greater than the rate of cellular respiration. In other words, the plant must produce more glucose than it consumes. There are two ways to increase the amount of glucose a plant can produce. Increasing the intensity or brightness of the light. This can increase glucose production, but only up to a certain point. Beyond that point, the extra light energy can damage plant cells. Increasing the intensity of light can also increase transpiration. This can cause leaves to wilt. Increasing the duration of the light. It is generally not possible to increase the number of sunlight hours in a day. Increasing the length of time beyond this requires artificial light. Light Compensation Point There is a specific intensity of light at which the rate of CO2 uptake is the same as the rate of CO2 production. We call this intensity the light compensation point.

Luckily I have financial limits, the ideas I have floating around my head are costly! Particularly hard to maintain both high and low temps due to extreme weather, gone is the cool outside air used to help "cool" during nighttime lights on, real-life daytime is running 95+ degrees which is making it hard to get to 60's lights off inside tent, it's better to keep the day/night swing within 10 degrees if possible as regular large transitions hot to cool can cause undue stress and disrupt the photosynthetic process. I shall do my best to keep a 70-80 range day/night, weather permitting. The potential is there, the hard part is providing the conditions for said growth to occur, every single day/night cycle. So that potential can be reached. The countdown cycle begins as soon as the photoperiod is switched to flower, tick tock, each stage that passes dependant on the progress of the stage before it to dictate its development to the next. Week 1-3: The Flowering Stretch Flower growth requires much more "light" than veg growth, the plant initiates "stretch" to seek out possible future construction sites suitable for the higher requirements of flowers. Week 3-4: Formation of “Budlets” If the light was water and the bud sites were buckets, how many buckets would I need to fill the water? Ok, make that many. A plant isn't going to start to develop high-density clusters of budlets if the conditions/intensity of light does not exist in the first place to make use of it, it will develop dictated by the environment, no more no less. Nutrients are the spectrum pool of elemental resources, the materials from which all things are made of. Water is the universal solvent used to mix, combine and transport these elements Week 4-6: Fattening of the Buds Week 6-8: Ripening of Buds Light has information stored as energy, blue holds almost 2x the energy in a blue photon as compared to red, cutting back on the intensity of full spectrum light and replacing it with high blues, gives me a idea 💡 Photosynthesis is driven by the energy input of light. A photon of Blue light holds 2.75 eV potential A photon of Red light holds 1.65 eV potential PPAR is driven by photons of light over a given m2 space per second. PPFD During Flowering Phase (12 hr daily light cycle):minimum light needed 463 μMols, maximum light needed 925 μMols But μMols do not distinguish the type of particles being used and are based on full spectrum "sunlight". 925 μMols of Blue photons in 1m squared every second the potential energy supplied to plant 925 x 2.75 = 2543.75eV 925 μMols of Red photons in 1m squared every second the potential energy suppplied to plant 925 x 1.65 = 1526.25eV The energy held within a photon of blue is roughly 2.75eV, it gets even higher in violet / UV range reaching 4.42eV per photon at 280nm. If this isn't being absorbed to drive photosynthesis, then what's going on with all that juice? Wavelengths between 400-700nm drive photosynthesis. Photosystems, large complexes of proteins and pigments (light-absorbing molecules) that are optimized to harvest light, play a key role in light reactions. There are two types of photosystems: photosystem I (PSI) and photosystem II (PSII). Both photosystems contain many pigments that help collect light energy, as well as a special pair of chlorophyll molecules found at the core (reaction center) of the photosystem. The special pair of photosystem I is called P700, while the special pair of photosystem II is called P680. In a process called non-cyclic photophosphorylation PAR or photosynthetic radiation are waves in the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. UV-B resistance 8 (UVR8) also known as ultraviolet-B receptor UVR8 is an UV-B – sensing protein found in plants and possibly other sources. It is responsible for sensing ultraviolet light in the range of 280-315 nm and initiating the plant stress response. It is most sensitive at 285nm, near the lower limit of UVB. UVR8 was first identified as a crucial mediator of a plant's response to UV-B in Arabidopsis thaliana containing a mutation in this protein. This plant was found to have a hypersensitivity to UV-B which damages DNA. UVR8 is thought to be a unique photoreceptor as it doesn't contain a prosthetic chromophore but its light-sensing ability is intrinsic to the molecule Tryptophan (Trp) residue 285 has been suggested to act the UV-B sensor, while other Trp residues have been also seen to be involved (Trp233 Trp337 Trp94) although in-vivo data suggests that Trp285 and Trp233 are most important. UVR8, previously described as an ultravioltet-B (UV-B, 280-315 nm), in sunlight functions both as an ultraviolet-A (UV-A, 315-400 nm) and UV-B photoreceptor. Although UVR8 presents maximal absorption at the boundary between ultraviolet-C (UV-C,

Observations, although I'm using top-down fluorescent lighting angled at 45% A light spectrum in the scope of 400 to 700nm induces growth and development, and UV (100–400nm) and infrared (700–800nm) light play a role in plant morphogenesis—which is essentially the process of plants developing their physical form and external structure. Optimizing Your Knowledge in the Grow Room To maximize your yield, always aim for 40 moles, or 40,000,000 μmol, per day. Here is how much PPFD is needed per second for each phase of cannabis growth to achieve the DLI of 40 moles of light per day. Seedling phase (18hr cycle): 200–300 μmol m-2 s-1 Vegetative phase (18hr cycle): 617 μmol m-2 s-1 Flowering phase (12hr cycle): 925 μmol m-2 s-1, (1500 μmol m-2 s-1 @2000ppm co2) (ballpark) When choosing grow lights for cannabis, it is essential to check the technical specifications to determine if they are strong enough to get the job done. Of course, this doesn't mean that you have to buy the most expensive lights there are. Still, it does mean that you should research each of these specifications in relation to your cannabis plants to find a grow light that will fully serve your needs. This is especially true with PPFD, as this is arguably the most insightful value for growers—it tells you exactly how much useful light your plants are absorbing at a certain distance from the grow light. With my fixed light source, as the plant develop height through stages, it will naturaslly grow into higher μmol ranges naturally dictated by its height. Look forward to filling the tent for the next grow. Last week will see increased blues. ELONGATED HYPOCOTYL5 (HY5), a bZIP-type transcription factor, acts as a master regulator that regulates various physiological and biological processes in plants such as photomorphogenesis, root growth, flavonoid biosynthesis and accumulation, nutrient acquisition, and response to abiotic stresses. HY5 is evolutionally conserved in function among various plant species. HY5 acts as a master regulator of a light-mediated transcriptional regulatory hub that directly or indirectly controls the transcription of approximately one-third of genes at the whole genome level. The transcription, protein abundance, and activity of HY5 are tightly modulated by a variety of factors through distinct regulatory mechanisms. This review primarily summarizes recent advances in HY5-mediated molecular and physiological processes and regulatory mechanisms on HY5 in the model plant Arabidopsis as well as in crops. Plants utilize light as the predominant energy source for photosynthesis. Besides, light signal acts as an essential external factor that mediates a variety of physiological and developmental processes in plants. Plants are continuously exposed to dynamically changing light signals due to the daily and seasonal alternation in natural conditions. The various light signals are perceived by at least five classes of wavelength-specific photoreceptors including phytochromes (phyA-phyE), cryptochromes (CRY1 and CRY2), phototropin (PHOT1 and PHOT2), F-box containing flavin binding proteins (ZTL, FKF1, and (LKP2), and UV-B RESISTANCE LOCUS 8 (UVR8). These photoreceptors are biologically activated by various light signals, subsequently initiating a large scale of transcriptional reprogramming at the whole genome level. Extensive genetic and biochemical studies have established that the ELONGATED HYPOCOTYL5 (HY5), a bZIP-type transcription factor, tightly controls the light-regulated transcriptional alternation. Loss of HY5 function mutant seedlings display drastically elongated hypocotyls in various light conditions, suggesting that HY5 acts downstream of multiple photoreceptors in promoting photomorphogenesis in plants. In addition to inhibiting hypocotyl growth, HY5 regulates other various physiological and developmental processes including root growth, pigment biosynthesis and accumulation, responses to various hormonal signals, and low and high temperatures. This review summarizes the recent advances and progress in HY5-regulated cellular, physiological, and developmental processes in various plant species. We also highlighted emerging insights regarding the HY5-mediated integration of multiple developmental, external, and internal signaling inputs in the regulation of plant growth. Among the genes regulated by the circadian clock, we found that the excision repair protein XPA is controlled by the biological clock, and we, therefore, asked whether the entire nucleotide excision repair oscillates with daily periodicity. XPA transcription and protein levels are at a maximum at around 5 pm and at a minimum at around 5 am. Importantly, the entire excision repair activity shows the same pattern. This led to the prediction that mice would be more sensitive to UV light when exposed at 5 am (when repair is low), compared to 5 pm (when repair is high). We proceeded to test this prediction. We irradiated two groups of mice with UV at 5 am and 5 pm, respectively, and found that the group irradiated at 5 am exhibited a 4–5 fold higher incidence of invasive skin carcinoma than the group irradiated at 5 pm. Currently, we are investigating whether this rhythmicity of excision repair exists in humans. Molecular mechanism of the mammalian circadian clock. CLOCK and BMAL1 are transcriptional activators, which form a CLOCK-BMAL1 heterodimer that binds to the E-box sequence (CACGTG) in the promoters of Cry and Per genes to activate their transcription. CRY and PER are transcriptional repressors, and after an appropriate time delay following protein synthesis and nuclear entry, they inhibit their own transcription, thus causing the rise and fall of CRY and PER levels with circa 24-hour periodicity (core clock). The core clock proteins also act on other genes that have E-boxes in their regulatory regions. As a consequence, about 30% of all genes are clock-controlled genes (CCG) in a given tissue and hence exhibit daily rhythmicity. Among these genes, the Xpa gene, which is essential for nucleotide excision repair, is also controlled by the clock. Circadian control of excision repair and photocarcinogenesis in mice. The core circadian clock machinery controls the rhythmic expression of XPA, such that XPA RNA and protein levels are at a minimum at 5 am and at a maximum at 5 pm. The entire excision repair system, therefore, exhibits the same type of daily periodicity. As a consequence, when mice are irradiated with UVB at 5 am they develop invasive skin carcinoma at about 5-fold higher frequency compared to mice irradiated at 5 pm when repair is at its maximum. The mouse in the picture belongs to the 5 am group with multiple invasive skin carcinomas at the conclusion of the experiment.

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