The work was devoted to the study of the influence of endophytic plant growth-promoting bacteria (PGPB) Bacillus subtilis strain 10-4 on wheat plants Triticum aestivum L. subjected to dehydration, induced by 12% PEG. Presowing seed treatment with endophytes at the concentration of 105 CFU mL−1 had stimulating and protective effects on the wheat plants growth under normal and stress conditions, respectively, which was judged on biomass accumulation, linear dimensions and visual appearance of the seedlings. The positive action of PGPB may be determined by the effects on the wheat hormonal system, as indicated by the data on increasing in the seedlings of the auxins content under normal conditions and prevention of its reduction under stress. PGPB-pretreatment decreased the stress-induced levels of abscisic acid (ABA) accumulation and cytokinin (CK) content diminution in the seedlings. Moreover the protective effect of B. subtilis 10-4 can be determined by their stabilizing effects on the membrane cell structures and water regime balance of wheat plants under dehydration.

Nitric oxide is a common signaling molecule involved in the modulation of metabolic activity during normal growth and development of plants and during the formation of their resistance to environmental stress factors. The review presents key information reflecting the current state of the problem of the regulatory role of NO in plants. Brief information is given about the physicochemical properties of NO, methods for its study, biosynthesis pathways, and functional activity at different stages of plant development (germination, vegetative growth, flowering, root formation, symbiosis, mineral nutrition). In addition, the manifestation of the protective effects of NO under conditions of moisture deficiency is described since the violation of the water regime and dehydration of plants is observed under the influence of various abiotic stress factors, including drought, salinity, and hypo- and hyperthermia. Particular attention is paid to the molecular mechanisms of NO-dependent signaling, which are realized in plants at the genomic, proteomic, and postproteomic levels during multiple nitration reactions. Understanding the mechanisms of the regulatory action of NO in normal conditions and under stress is of great theoretical and applied importance because of the need for a fundamental substantiation of the possibility of practical application of NO in order to increase the resistance and productivity of cultivated plants.

On March 3, 2024, sad news spread among Russian plant physiologists: an outstanding scientist and wonderful person, Farida Minnikhanovna Shakirova, died. Friends and colleagues exchanged letters in an attempt to honor her memory. Members of Editorial board of the journal “Ecobiotech”, created by colleagues F.M. Shakirova, decided to write about her scientific activities and her amazing qualities: kindness, dedication to science, efficiency, talent as a researcher, willingness to share her experience with colleagues. We would like young colleagues who did not have the opportunity to know her personally to learn from her example.

Nitric oxide is a universal signaling molecule involved in the modulation of metabolic activity during the normal growth and development of plants, and in the formation of their resistance to environmental stressors. The review presents key information that reflects the current state of the problem of the regulatory role of NO in plants. Brief information on physicochemical properties of NO, methods of its research, ways of biosynthesis and functional activity at different stages of plant development (germination, vegetative growth, flowering, root formation, symbiosis, mineral nutrition) are given.In addition, the appearance of the protective effects of NO under conditions of moisture deficiency is described, since disturbance of the water regime and dehydration of plants is observed under the influence of various abiotic stress factors, including drought, salinity, hypo- and hyperthermia. Particular attention is paid to the molecular mechanisms of NO-dependent signaling, which are implemented in plants at the genomic, proteomic and post-proteomic levels during multiple nitration reactions. Understanding the mechanisms of regulatory action of NO in normal and under stress is of important theoretical and applied importance in connection with the need for a fundamental justification of the possibility of practical use of NO in order to increase the stability and productivity of cultivated plants.

Nitric oxide (NO) is a universal signaling molecule that functions in all living organisms. It is involved in the regulation of plant growth and development as well as in the formation of plant resistance to a wide range of stress factors. Along with tremendous progress in understanding the role and mechanisms of NO regulatory action achieved in the past three decades, the pathways of NO biosynthesis in plant organisms are far from being fully understood and remain the subject of heated discussions. Analysis of current literature reveals two principally different mechanisms of NO formation in higher plants: the oxidative or arginine-dependent pathway and the reductive or nitrate/nitrite-dependent pathway. In the first case, nitric oxide is produced during the interaction of arginine with oxygen, which proceeds with the formation of citrulline and the release of an NO molecule. However, the enzymes responsible for oxidative formation of NO in higher plants have not yet been identified. The nitrite-dependent formation of NO is the best studied pathway, in which particular roles belong to molybdenum-containing enzymes, such as nitrate reductase (NR) and the amidoxime reductase mARC (mitochondrial amidoxime reducing component). Xanthine oxidoreductase (XOR), aldehyde oxidase (AO), and sulfite oxidase (SO) may also contribute to NO production. This review presents a detailed analysis of the main mechanisms of NO formation in higher plants.

Endophytic bacteria Bacillus subtilis, which belongs to plant growth promoting microorganisms, are considered as an alternative to agrochemicals for increasing of wheat drought stress tolerance.

Проведен анализ влияния предобработки донором оксида азота нитропруссидом натрия (SNPsodium nitroprusside) в концентрации 200 мкМ на физиологобиохимические показатели растений пшеницы (Triticum aestivum L.) в норме и в условиях засухи, моделируемой присутствием в среде инкубирования проростков 12%-го полиэтиленгликоля (ПЭГ).Предобработка 3-сут проростков пшеницы донором NO оказывала на них рост-стимулирующий эффект в нормальных условиях произрастания, и способствовала поддержанию ростовых процессов при засухе, о чем судили по показателям биомассы и внешнему виду проростков.Данные по снижению стрессиндуцированного накопления малонового диальдегида и выходу электролитов из тканей SNP-

Министерство науки и высшего образования РФ Российская академия наук Общество физиологов растений России Правительство Республики Татарстан Федеральный исследовательский центр «Казанский научный центр Российской академии наук» Казанский институт биохимии и биофизики ФИЦ КазНЦ РАН Институт физиологии растений им.К.А

Министерство науки и высшего образования РФ Российская академия наук Общество физиологов растений России Правительство Республики Татарстан Федеральный исследовательский центр «Казанский научный центр Российской академии наук» Казанский институт биохимии и биофизики ФИЦ КазНЦ РАН Институт физиологии растений им.К.А

We investigated effects of sodium nitroprusside (SNP), the donor of nitric oxide (NO), on the growth and hormonal system of wheat plants ( Triticum aestivum L.) in normal conditions and after salt stress (2% NaCl). During germination of seeds treated with SNP (50–500 μM), we obtained the SNP concentration (200 μM) optimal for stimulation of seedling growth estimated by increase in seed germination capacity and seedlings' linear sizes and their fresh and dry biomass. A comparative analysis of SNP (200 μM) effects, after seed germination in the medium with SNP or pretreatment of 3-day-old seedlings, showed SNP ability to increase the wheat plant resistance to subsequent effects of sodium chloride salinity at both treatment methods. Protective SNP effects appeared in the reduction of stress inhibitory action on seedling growth rates and significant reduction in the level of lipid peroxidation and exosmosis of electrolytes. An important contribution to realization of the growth-stimulating and protective effects of NO is associated with its ability to influence the state of the hormonal system of wheat plants due to an increase in the concentration of hormones of a cytokinin nature under normal conditions and the prevention of a decrease in their level under stress.

We have studied the influence of pretreatment of wheat seedlings (Triticum aestivum L.) with 50 mu M salicylic acid (SA) on plant resistance to subsequent action of 1 mM cadmium acetate. SA pretreatment decreased the extent of detrimental effect of cadmium on wheat plants, as judged by the decline in the level of stress-induced accumulation of MDA and electrolyte leakage. Furthermore, SA-pretreatment contributed to maintenance of growth characteristics of wheat seedlings at the level close to the control under stress conditions and to acceleration of growth recovery during post-stress period. Detected defense effect of SA may be due to a decline in the amplitude of cadmium-induced accumulation of abscisic acid (ABA) and to reduced fall of indoleacetic acid (IAA) and cytokinins (CK) in stressed plants. In the course of one day treatment, SA activated phenylalanine ammonia-lyase (PAL), the key enzyme of lignin biosynthesis, in roots of seedlings under normal growth conditions contributing to the strengthening of carrier functions of cell walls. This assumption is supported by the data showing significant decline in cadmium accumulation in SA-pretreated plants, especially in the shoots. Cd-treatment was shown to result in accumulation of dehydrins with molecular mass 22, 28, 55 and 69 kDa in wheat seedlings, although low molecular weight dehydrins (22 and 28 kDa) showed greater stress sensitivity. It is noteworthy that SA-pretreatment by itself led to 1.5-fold increase in the content of low molecular weight dehydrins. Nevertheless, SA-pretreated seedlings were characterized by significantly lower Cd-induced accumulation of all of the four dehydrins, apparently due to inhibition of cadmium flow into the plants. The obtained data suggest involvement of dehydrins in the range of defense reactions induced by SA-treatment contributing significantly to development of plant resistance to subsequent action of stress. The use of fluridone allowed us to demonstrate the key role of endogenous ABA in SA-induced changes in the level of dehydrins as well as in the protective effect of SA on wheat plants under cadmium stress resulting from development of defense responses in the course of SA-treatment. (C) 2015 Elsevier B.V. All rights reserved.

Effect of pretreatment of wheat (Triticum aestivum L.) seedlings with 0.4 μM 24-epibrassinolide (EB) on subsequent action on them of 1 mM cadmium acetate was investigated. This pretreatment decreased the extent of damage of cadmium action on wheat plants as judged by inhibition of stress-induced efflux of electrolytes from plant tissues and plant ability to maintain the growing parameters at a level close to the control. It was established that the revealed ability of EB to induce twofold increased accumulation of 28 kDa dehydrin under normal plant growth conditions and even to cause additional accumulation of this protein under the cadmium stress is of importance in development of the preadapting and protection effects of EB on wheat seedlings. Using fluridone (FD), a known inhibitor of the biosynthesis of ABA, the pathways responsible for the regulation of 28 kDa dehydrin level and both dependent and independent on ABA were revealed in wheat plants both pretreated and untreated with EB and under cadmium stress.

Cytokinin oxidase (EC 1.5.99.12) is an enzyme that catalyzes the irreversible degradation of cytokinin phytohormones that are extremely necessary for growth, development, and differentiation of plants. Cytokinin oxidase plays an important role in the regulation of quantitative level of cytokinins and their distribution in plant tissues. This review generalizes the available information on the structure, properties, and functional role of this enzyme in plant ontogeny under conditions of normal growth and under the influence of unfavorable environmental factors.

We studied the influence of the pretreatment of wheat seedling ( Triticum aestivum L.) with 0.4 μM 24-epibrassidinolide (EB) on the growth and hormone status of plants under the influence of 2% NaCl. The pretreatment with EB promoted the lowering of the extent of the damaging influence of salinity on the growth of seedling. The important contribution to the realization of the protective action of EB in the pretreatment of plants is probably that of its ability to lower the level of stress-induced abscisic acid accumulation and the decrease in the content of indole-acetic acid. At the same time, the cytokinin concentration in plants pretreated with EB under salinity was practically the same as in plants without stress. This fact combined with data about the ability of EB to induce the increase in cytokinin content in wheat, obtained before, allowed us to assume that the protective action of EB on plants is connected, first of all, with the prevention of the decrease in level of hormones of cytokinin nature under salinity.