Complete details of abscisic acid

Abscisin, Dormin, ABA. A plant hormone that inhibits growth, named for its ability to shed leaves. May be widely distributed in higher plants. Besides inducing

Abscisin, Dormin, ABA. A plant hormone that inhibits growth, named for its ability to shed leaves. May be widely distributed in higher plants. Besides inducing leaves to fall off, it has other functions, such as inducing buds to go into dormancy and inducing potatoes to form tubers. It also inhibits cell elongation. In 1965, it was confirmed that exfoliating element ⅱ and dormancy element are the same substance, named abscisic acid.

Chinese name: Abscisic Acid English name: abscisic acid(ABA) alias: abscisic acid, dormant element chemical formula: c 15 H2O 4 molecular weight: 264.32 CAS registration number: 2 1293-29-8 EINECS registration number: 244-31. L density: 1. 193 g/mL appearance: white powder application: basic agricultural information, numbering system, molecular structure data, computational chemistry data, nature and stability, hazard information, introduction, definition, discovery, nature, action, metabolism, biosynthesis, action mechanism, signal network mechanism, application and value. (S)-5-( 1- hydroxy -4- oxo -2,6,6-trimethyl -2- cyclohexene-1- yl) -3- methyl -(2Z, 4E)- pentadienoic acid; ABA, dormancy element; English name: (+)-abstract acid English alias: 2,4- pentadienoic acid, 5-( 1- hydroxy -2,6,6-trimethyl -4- oxo -2- cyclohexene-1- yl) -3- methyl-. Si Nuo. : 2 1293-29-8 molecular formula: c15h2o4 molecular weight: 264.3 1700 exact mass: 264.13600psa: 74.60000 logp: 2.24990 numbering system. : 244-3 19-5 rtecNo.: rz2475 1 00 brnno: 2130328 PublicationNo.: 2489092 1 molecular structure data1,molar refractive index:. Molar): 22 1.53, isotonic specific volume (90.2k): 593.64, surface tension (dyne/cm): 5 1.55, polarizability (10-24cm3): 29.34. Number of hydrogen bond donors: 2 3, number of hydrogen bond acceptors: 4 4, number of rotatable chemical bonds: 3 5, number of tautomers: 5 6, polar surface area (TPSA) of topological molecules: 74.67, number of heavy atoms: 1 9 8, surface charge: 0.9, complexity: 494 10. Determine the number of atomic solid centers: 1 12, uncertain atomic solid centers: 0 13, determined chemical bond solid centers: 2 14, uncertain chemical bond solid centers: 0 15, and * * valence bond units:/kloc. 2. Sensitive to light, belonging to strong light decomposition compounds. 3. It exists in tobacco leaves. Emergency: causing skin irritation. Causing severe eye irritation. Can cause respiratory irritation. GHS risk category: skin corrosion/irritation category 2 Serious eye injury/eye irritation category 2 First exposure to specific target organ toxicity category 3 Warning words: Warning hazard description: H3 15 causes skin irritation. H3 19 causes severe eye irritation. H335 can cause respiratory irritation. Precautions: Clean thoroughly after P264 operation. P280 Wear protective gloves/clothes/goggles/masks. P26 1 Avoid inhaling dust/smoke/gas/smoke/steam/spray. P27 1 can only be used outdoors or in a well-ventilated place. Accident reverberation: P302+P352 If the skin is polluted, rinse with water. P332+P3 13 If skin irritation occurs, please seek medical attention. P362+P364 Take off the contaminated clothes and wash them before use. P305+P35 1+P338 If it enters eyes, rinse it carefully with water for several minutes. If you wear contact lenses and can easily take them out, take them out. Keep flushing. P337+P3 13 If you still feel eye irritation, please see a doctor. P304+P340 If inhaled by mistake: Move the patient to fresh air and keep breathing comfortable. P3 12 If you feel unwell, call a drug rehabilitation center/doctor for safe storage: P403+P233 is stored in a well-ventilated place. Keep the container sealed. P405 Storage location should be locked. Disposal: P50 1 Dispose of contents/containers according to local regulations. Health hazard: cause skin irritation. Causing severe eye irritation. Can cause respiratory irritation. Abscisic acid refers to plant hormones that can cause bud dormancy, leaf abscission and inhibit cell growth. A plant hormone that inhibits growth, named for its ability to shed leaves. May be widely distributed in higher plants. Besides inducing leaves to fall off, it has other functions, such as inducing buds to go into dormancy and inducing potatoes to form tubers. It also inhibits cell elongation. Abscisic acid (aba) is a plant hormone and one of the five natural growth regulators in plants. At present, the industrial fermentation of Botrytis cinerea to produce natural abscisic acid has been realized, with high purity and high biological activity, which will be applied to agricultural production on a large scale in the future. Abscisic acid can be metabolized by oxidation and combination. Abscisic acid can stimulate the production of ethylene, promote fruit ripening and inhibit the synthesis of deoxyribonucleic acid and protein. During the Beijing Olympic Games, abscisic acid was applied to millions of pots of flowers in Beijing to ensure the flowers bloom. Abscisic acid is a plant hormone with sesquiterpene structure. In 1963, Eddie Cote and others in the United States purified a substance from cotton bolls, which can significantly promote the petiole shedding of cotton seedling explants, and it is called shedding II. Britain, etc. A substance, called dormancy element, was purified from the leaves of Acer negundo under short-day conditions, which can control the dormancy of deciduous trees. In 1965, it was confirmed that exfoliating element ⅱ and dormancy element are the same substance, named abscisic acid. It was found that during the period of 196 1 year, Liu Wencong and H.R. Kearns separated a substance crystal from mature cotton bolls, which could accelerate the petiole shedding of explants after defoliation, and was called "exfoliant ⅰ", but its chemical structure has not been identified. In 1963, Kazuhiko Ursa and F.T. Adikot separated another substance crystal which accelerated cotton boll shedding, called shedding II. In the same year, C.F. iggers and P.F. Wareing separated an inhibitory substance from Acer truncatum leaves by chromatography, which could make the growing seedlings and buds dormant. They named it the dormant element. After comparing the chemical properties of dormancy and shedding Ⅱ in 1965, Wareing et al. proved that they are the same substance, and the molecular formula is the same as that proposed by Kazuhiko Ohbear et al. in 1965. Uniformly named abscisic acid. It is ubiquitous in plants. Abscisic acid is a sesquiterpene compound with 15 carbons. Natural abscisic acid is an enantiomeric structure, especially the dextrorotatory compound ABA. The physiological activity of (R)-ABA is the same as that of (S)-ABA in most cases. Its physiological activity depends on the following conditions: ① free carboxyl; ② Double bonds at α-or β-position on cyclohexane ring; ③c-2 cis double bond. 2- trans ABA has no activity before isomerization under light. The free acids produced by ester compounds after ester chain hydrolysis are also active. Natural abscisic acid is a white crystalline powder, which is easily soluble in methanol, ethanol, acetone, chloroform, ethyl acetate and chloroform, but insoluble in ether and benzene, and its water solubility is 3-5 g/L(20℃). Abscisic acid has good stability. After two years' storage at room temperature, the content of active ingredients is basically unchanged, but it should be stored in a dry, cool and dark place. Abscisic acid aqueous solution is sensitive to light and belongs to strong light decomposition compound. Zhang Dapeng found that abscisic acid receptor, natural abscisic acid, auxin, ethylene, gibberellin and cytokinin are the five major hormones in plants, which can improve the drought resistance and salt tolerance of plants, and are of great value to the development and utilization of low-yield fields, afforestation and desert greening. ABA is also an effective inhibitor to inhibit seed germination, which can be used for seed storage to ensure the storage quality of seeds and fruits. In addition, ABA can also cause the stomata of leaves to close quickly, which can be used to keep flowers fresh, regulate flowering period and promote rooting, and has great application value in flower gardening. The study of ABA and its response genes can reveal the molecular process of plants' response to stress physiology, thus laying a foundation for directionally enhancing the adaptability of crops to the environment. Abscisic acid has a broad application prospect in agricultural production, which can produce huge economic and social benefits. Because the optical configuration of natural abscisic acid in plants is only (+)-cis-ABA and trans-ABA, the traditional chemical synthesis method is extremely expensive, so it is only used in large-scale agricultural production in developed countries such as Japan and the United States. From the name of abscisic acid, it is known that accelerating the shedding of plant organs is an important physiological function of ABA. There are different views on the shedding of leaves, flowers and fruits caused by ABA. As one of the discoverers of ABA, Adikot (1982) believes that endogenous ABA can promote abscission. However, the field experiment with ABA as defoliant was not successful. This may be because IAA, GA and CTK in leaves can counteract ABA. Milborrow( 1984) thinks that exogenous ABA can cause defoliation, but its effect is lower than that of exogenous ethylene. When Osborne( 1989) commented on the effects of ethylene and ABA on abscission, he came to the conclusion that ABA may not have a direct effect on abscission, but only cause premature aging of organ cells, and then stimulate the increase of ethylene and cause abscission. The real initiator of shedding process is ethylene, not ABA. In the biological experiment of ABA, the soybean leaves (or cotton leaves) are generally detached, and the lanolin is confused on the residual roots of the opposite petiole, and the shedding speed is observed. In addition, elongation inhibition of oat or wheat coleoptile fragments was also used. Growth inhibition ABA is a strong growth inhibitor, which can inhibit the growth of whole plants or isolated organs. The effect of ABA on growth is opposite to IAA, GA and CTK, and it inhibits cell division and elongation. It inhibits the elongation and growth of coleoptile, bud, root and hypocotyl. Promoting dormancy In the short sunshine in autumn, the ABA content in leaves of many woody plants increased, prompting buds to enter dormancy. Applying ABA to the vigorous branchlets of these woody plants will lead to bud dormancy. The dormant buds of potato also contain more ABA. Therefore, potato can be treated with ABA to prolong its dormancy period. Dormant seeds such as Korean pine, peach, chestnut and maple contain more ABA. After several months of low temperature stratification, the ABA content in seeds decreased and the germination rate increased significantly. But ABA content is not necessarily the direct cause of seed dormancy. The ABA content in seed coat of Korean pine is high. After washing, ABA content decreased obviously, but the germination rate was still very low. Further analysis of ABA content in seeds of Pinus yunnanensis, Pinus tabulaeformis, Pinus armandii and Pinus bungeana showed that ABA content in some pine seeds was also high, but it did not show dormancy. For example, the ABA content of non-dormant Pinus armandii seeds is about 10 times higher than that of dormant Pinus koraiensis seeds. The germination of lettuce, radish and other seeds was also inhibited by ABA. Cause the stomata to close and adjust the stomata opening. ABA regulates stomatal closure through two signal transduction pathways: promoting stomatal closure and inhibiting stomatal opening. Under the condition of water shortage, ABA content in plant leaves increased, leading to stomata closure. This is because ABA promotes the outflow of potassium ions, chloride ions and malate ions, thus promoting stomatal closure. Spraying plant leaves with ABA aqueous solution can close stomata and reduce transpiration rate. Therefore, ABA can be used as anti-transpiration agent. In addition, ABA inhibits the action of potassium ion and proton pump, thus inhibiting stomatal opening. ABA promotes stomatal closure and regulates the development of seed embryos. In recent years, people have noticed that endogenous ABA, as a positive regulatory factor, plays an important role in the development of seed embryos. Endogenous ABA can make embryos mature normally and inhibit premature germination. Exogenous ABA can accelerate the formation of some special storage proteins in immature embryo culture; Without ABA, these embryos can either not synthesize these protein or form little protein. This shows that ABA level in early and middle stages of seed development controls the accumulation of storage proteins. Whether ABA also controls the accumulation of starch and fat in developing embryos is a problem to be studied. In addition, ABA can also be used as a substance to protect plants from salt, heat and cold, which may be related to its ability to promote plants to produce new stress proteins. ABA can also promote flower bud differentiation of some fruit trees (such as apples) and promote some short-day plants (such as blackcurrant) to bloom under long sunshine conditions. Generally speaking, drought, cold, high temperature, salinity and waterlogging can make ABA in plants increase rapidly and enhance stress resistance. For example, ABA can significantly reduce the damage of high temperature to chloroplast ultrastructure and increase the thermal stability of chloroplast; ABA can induce the biosynthesis of some enzymes and increase the cold resistance, waterlogging tolerance and salt tolerance of plants. So ABA is called stress hormone or stress hormone. Gibberellin can make the female plants of hemp form male flowers, which can be reversed by abscisic acid, but abscisic acid can't make the male plants form female flowers. Metabolic abscisic acid is mainly synthesized in root crowns and wilting leaves, and organs such as stems, seeds, flowers and fruits also have the ability to synthesize abscisic acid. For example, abscisic acid can be synthesized in the cytoplasm of spinach mesophyll cells and then transported to various parts of the cells. Abscisic acid is a weak acid, and the matrix of chloroplast has a high pH value, so abscisic acid accumulates in chloroplast in ionized state. The abscisic acid content in grape ABA can be inactivated by binding with monosaccharides or amino acids in cells by valence bonds. The bound ABA can be hydrolyzed to release ABA again. Therefore, bound abscisic acid is the storage form of abscisic acid. However, the rapid increase of ABA caused by drought is not from the hydrolysis of bound ABA, but from the re-synthesis. Oxidation of abscisic acid The oxidation products of abscisic acid are monobasic acid and dibasic acid. The activity of crocetin is extremely low, and dihydrocrocetin has no physiological activity. There are two main biosynthetic pathways of abscisic acid: terpenoid pathway. In this way, abscisic acid is synthesized from methylbenzoic acid (MVA) through isopentenic acid pyrophosphate (IPP) and farnesyl pyrophosphate (FPP), and then abscisic acid is formed through some unknown processes. This route is also called C 15 direct route. MVA →→→ FPP →→ Aba. Carotenoid pathway In this pathway, the precursors of abscisic acid, isoprenoid pyrophosphate (IPP) and dimethyl propylene pyrophosphate (DMAPP), are not synthesized through MVA pathway, but through 2-C- methyl -D- erythritol -4- phosphate pathway (MEP/DOXP pathway) and fragrance. Farnesyl pyrophosphate (C 15, farnesyl pyrophosphate, FPP), geranyl geranyl pyrophosphate (C20, GGPP) until all-trans-β -carotene (all-trans -GGPP) was synthesized. The carbon skeleton of abscisic acid is similar to the terminal part of some carotenoids. Tarlor and others produce growth inhibitors when carotenoids are exposed to light. Later, it was found that the inhibitor of violaxanthin under light was 2- cis-xanthophyll, which was also found in some plants. Xanthan gum is rapidly metabolized into abscisic acid. In recent years, it has been found that other carotenoids (such as neoxanthin, lutein, lutein, etc. ) can be photolyzed or converted into xanthaldehyde under the action of lipoxygenase, and finally abscisic acid is formed. The pathway of ABA production by oxidative decomposition of carotenoids is called the indirect pathway of ABA synthesis. The biosynthesis of abscisic acid is generally considered that ABA is mainly synthesized indirectly in higher plants. Direct pathway refers to the process of directly synthesizing ABA from C 15 compound (FPP). Indirect pathway refers to the process that C40 compounds produce ABA through oxidative decomposition. (Masaji Suzuki, 1998) Mechanism of Action The physiological function of abscisic acid is mainly to cause dormancy and promote shedding. Treating vigorous shoots with abscisic acid can cause the same state as dormancy; The leaves that produce bud scales replace the unfolded vegetative leaves; Reduce mitotic activity of apical meristem; And it will cause the leaves below to fall off and prevent the dormancy from being released. Treating germinated seeds with abscisic acid can make them dormant. Treatment with gibberellin or cytokinin can counteract or reverse this inhibitory effect on germination. Abscisic acid can antagonize the effect of gibberellin instead of long-day sunlight on flowering of long-day plants. It is also possible for a few short-day plants to bloom without induction cycle. Conversely, several effects of abscisic acid can also be offset by gibberellin. For example, gibberellin can overcome the inhibition of elongation of highly heritable corn and abscisic acid on seed germination and potato germination. In addition, abscisic acid has the opposite effect to cytokinin. Abscisic acid has antagonistic effect on gibberellin and cytokinin plants. But these antagonistic effects are very complicated. For example, lettuce seeds need light for germination, and gibberellin can replace light. Abscisic acid can counteract the effect of gibberellin on promoting germination, but continuing to increase gibberellin concentration can not overcome the effect of abscisic acid and restore the promotion of germination. ABA plays a role in controlling the synthesis of nucleic acid and protein. Abscisic acid inhibits the synthesis of α -amylase in barley grains and antagonizes gibberellin in the process. The inhibitory effect on enzyme synthesis is similar to that of RNA synthesis inhibitors 8- azaguanine and 6- methylpurine, indicating that abscisic acid may inhibit the synthesis of RNA that determines the structure of α -amylase or prevent RNA from combining with active enzyme units. Abscisic acid inhibited RNA synthesis in dandelion leaves, but inhibited DNA synthesis in Pinctada. Because abscisic acid is expensive, there are few experiments in agricultural production. The researchers of signal network mechanism found the latest structural analysis results of a key subfamily in ABA signal network: PP2Cs, thus revealing the new mechanism of this signal pathway. Researchers reported the structure of SnRK2-PP2C complex, from which it was found that SnRK2 and ABA receptors recognized PP2C surprisingly similarly. SnRK2 (sucrose non-fermented 1 related protein kinase) is a kind of Ser/Thr protein kinase widely existing in plants, which is involved in the transduction of various signal pathways in plants and plays an important role in the physiological process of plant stress resistance. In this complex, the active group of kinase binds to the active site of PP2C, while the conservative ABA binding site senses the catalytic opening of tryptophan inserted into kinase, thus simulating the receptor -PP2C interaction. These structural biological results suggest a simple new mechanism, that is, the coupled ABA can directly bind to the active site of SnRK2 kinase; This also reveals a new regulation law of kinase-kinase phosphatase. According to this law, the regulation of kinase-kinase phosphatase is realized through the mutual encapsulation of their catalytic sites. Abscisic acid has a broad application prospect in agricultural production, which can produce huge economic and social benefits. To sum up, there are mainly the following aspects: (1) abscisic acid is an effective seed germination inhibitor, which exists in dormant seeds of many plants as a major growth inhibitor. The seeds of many plants can be soaked with abscisic acid to prevent germination, and its effect is reversible. It is easy to leach from treated seeds and grow again, so abscisic acid can be used to inhibit seed germination for seed storage. (2) Abscisic acid can promote the accumulation of storage substances in seeds and fruits, especially storage proteins and sugars. External application of abscisic acid in the early stage of seed and fruit development can improve the yield of food crops and fruit trees. (3) abscisic acid can enhance the cold and frost resistance of plants, and can be used to help crops resist early spring freezing injury and cultivate new crop varieties with strong cold resistance. For example, in the Oda experiment in Beijing, winter wheat Xindong No.2 was soaked with 10~6 M for 24 hours and sowed in the experimental site on June 26th of the first year. The survival rate of the control was 5 1.4%, while the survival rate of abscisic acid soaking reached 96.3%. The effect of abscisic acid on improving the cold resistance of wheat has two characteristics: first, it can improve the cold resistance without inhibiting the growth; Second, it can induce the improvement of cold resistance under warm conditions. Usually, the cold resistance of plants can only be developed through low temperature exercise. These characteristics of abscisic acid are not only of great significance for discussing the expression and regulation of cold-resistant genes, but also may bring hope for preventing cold injury of overwintering crops in late spring. Sugar-coated haws (4) Abscisic acid in winter can improve the drought resistance and salt tolerance of plants, which is of great application value to help human beings resist the increasingly arid environment, develop and utilize low-and medium-yield fields, and plant trees. (5) Applying exogenous abscisic acid to wheat can inhibit stem elongation, increase ear weight and resist crop lodging; Low concentration abscisic acid can promote the formation and redifferentiation of adventitious roots, which has broad application prospects in tissue culture. Abscisic acid is a ubiquitous natural substance in plants. It naturally exists in fruits, vegetables and grains eaten by human beings, and is safe for human beings and the environment. The raw materials used in the production of abscisic acid are all non-toxic and harmless agricultural and sideline products, without any harmful factors or substances, and there are no toxic elements in its chemical structure. Abscisic acid is a key factor to balance the metabolism of endogenous hormones and growth-related active substances in plants. It has the ability to promote the balanced absorption of water and fertilizer by plants and coordinate metabolism in vivo, and can effectively regulate the root/crown, vegetative growth and reproductive growth of plants, which plays an important role in improving crop quality and yield. The application of abscisic acid can reduce the amount of chemical pesticides, which has important physiological activity and application value in improving the quality of agricultural products. In addition, exogenous abscisic acid can quickly close the stomata of leaves and inhibit transpiration, which can be used to keep fresh flowers or prevent wilting during the transportation of crop seedlings. Abscisic acid can also control flower bud differentiation and regulate flowering period, which has great application value in flower gardening. Abscisic acid is a pure natural plant growth regulator. The abscisic acid and its compound practical preparation can be widely used in rice, vegetables, flowers, lawns, cotton, Chinese herbal medicines, fruit trees and other crops. Therefore, the growth quality, seed setting rate and quality of crops in adverse growth environments such as low temperature, drought, late spring cold, salinization, pests and diseases can be improved, the unit yield of low-and medium-yield fields can be increased, and the amount of chemical pesticides can be reduced. Abscisic acid can be widely used in greening construction of urban lawns and gardens, water-saving agriculture, facility agriculture and ecological vegetation restoration and reconstruction in the western region, which is of great significance to the development of agricultural industrialization in China. Therefore, its economic, social and environmental benefits are remarkable. After the application market of abscisic acid practical preparations was opened, the direct economic benefits produced by production enterprises were hundreds of millions; When it is used in greenhouse vegetable production, it will recover the losses caused by cold injury and diseases and insect pests, and improve the competitiveness of domestic and foreign markets due to the improvement of vegetable quality and the reduction of pesticide residues, and the indirect benefits and indirect economic benefits for rice seed industry will also be hundreds of millions. S- elicitor abscisic acid is also called S- elicitor: At present, there are two factories in the world that use similar microorganisms and different fermentation methods to industrially produce natural abscisic acid, botrytis cinerea liquid fermentation and botrytis cinerea continuous solid-state fermentation. S- mutagen has been found to have new physiological functions, including inducing drought resistance, cold resistance, freezing resistance, salt tolerance and promoting rooting. S- mutagen, a "growth balance factor" in plants, is a key factor to balance the metabolism of endogenous hormones and related growth active substances in plants. It has the ability to promote the balanced absorption of water and fertilizer by plants and coordinate metabolism in the body. It can effectively regulate the root/crown, vegetative growth and reproductive growth of plants, and plays an important role in improving the quality and yield of crops. S- elicitor is the "stress inducing factor" of plants and the "first messenger" to start the expression of stress-resistant genes in plants, which can effectively activate the stress-resistant immune system in plants. It has the ability to enhance the comprehensive resistance of plants (drought resistance, heat resistance, cold resistance, pest resistance, salt and alkali resistance, etc.). ). It plays an important role in fighting drought and saving water, reducing disasters and ensuring production and restoring ecological environment in agricultural production. Environmental protection product S- mutagen is a pure natural product contained in all green plants, which is obtained by microbial fermentation with high purity and high growth activity. Non-toxic and non-irritating to humans and animals. It is a new and efficient natural green plant growth active substance. Market analysis abscisic acid should be said to be a product with a very good market prospect, which has a broad application prospect in agricultural production and can produce huge economic and social benefits. At present, the abscisic acid market at home and abroad is in the initial stage, and industrialized products will gradually enter the market after 200 1 year, with relatively high prices, insufficient product publicity, weak market development and expansion ability of production enterprises, and insufficient knowledge of abscisic acid products and its application effect among users in agriculture and related industries, which leads to a large market demand for abscisic acid products by users, on the other hand, insufficient production capacity and output of production enterprises. At present, the situation of abscisic acid in the international market is better than that in China. The United States, Japan and other countries have recognized and understood abscisic acid products, and began to gradually apply abscisic acid preparations to agricultural production, and the consumption of products is gradually increasing. However, in China, the industrial application of abscisic acid preparations is less, which leads to the overall development trend of abscisic acid market should be in short supply, but at present it is an abnormal situation of oversupply. For a long time to come, as long as we can fully develop the market and do a good job in product marketing, abscisic acid products will be in short supply in domestic and foreign markets for a long time.