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Several model plants are known to respond to bacterial quorum sensing molecules with altered root growth and gene expression patterns and induced resistance to plant pathogens. These compounds may represent novel elicitors that could be applied as seed primers to enhance cereal crop resistance to pathogens and abiotic stress and to improve yields. We investigated whether the acyl-homoserine lactone N-hexanoyl-L-homoserine lactone (C6-HSL) impacted winter wheat ( Triticum aestivum L.) seed germination, plant development and productivity, using two Ukrainian varieties, Volodarka and Yatran 60, in both in vitro experiments and field trials. In vitro germination experiments indicated that C6-HSL seed priming had a small but significant positive impact on germination levels (1.2x increase, p < 0.0001), coleoptile and radicle development (1.4x increase, p < 0.0001). Field trials over two growing seasons (2015–16 and 2016–17) also demonstrated significant improvements in biomass at the tillering stage (1.4x increase, p < 0.0001), and crop structure and productivity at maturity including grain yield (1.4–1.5x increase, p < 0.0007) and quality (1.3x increase in good grain, p < 0.0001). In some cases variety effects were observed (p ≤ 0.05) suggesting that the effect of C6-HSL seed priming might depend on plant genetics, and some benefits of priming were also evident in F1 plants grown from seeds collected the previous season (p ≤ 0.05). These field-scale findings suggest that bacterial acyl-homoserine lactones such as C6-HSL could be used to improve cereal crop growth and yield and reduce reliance on fungicides and fertilisers to combat pathogens and stress.

Heavy metals (HMs) are among the main environmental pollutants that can enter the soil, water bodies, and the atmosphere as a result of natural processes (weathering of rocks, volcanic activity), and also as a result of human activities (mining, metallurgical and chemical industries, transport, application of mineral fertilizers). Plants counteract the HMs stresses through morphological and physiological adaptations, which are imparted through well‐coordinated molecular mechanisms. New approaches, which include transcriptomics, genomics, proteomics, and metabolomics analyses, have opened the paths to understand such complex networks. This review sheds light on molecular mechanisms included in plant adaptive and defense responses during metal stress. It is focused on the entry of HMs into plants, its transport and accumulation, effects on the main physiological processes, gene expressions included in plant adaptive and defense responses during HM stress. Analysis of new data allowed the authors to conclude that the most important mechanism of HM tolerance is extracellular and intracellular HM sequestration. Organic anions (malate, oxalate, etc.) provide extracellular sequestration of HM ions. Intracellular HM sequestration depends not only on a direct binding mechanism with different polymers (pectin, lignin, cellulose, hemicellulose, etc.) or organic anions but also on the action of cellular receptors and transmembrane transporters. We focused on the functioning chloroplasts, mitochondria, and the Golgi complex under HM stress. The currently known molecular mechanisms of plant tolerance to the toxic effects of HMs are analyzed.

Phenolic compounds (PCs) in plants play an important role in growth control and have antioxidant, structural, attractant, signaling and protective functions. Information on the discovery, study and identification of phenolic compounds in plants, their role in the complex system of secondary metabolites has been analyzed and summarized. The functions of PCs at the macromolecular, cellular as well as organism and population levels are described. The pathways of PCs formation, enzymes responsible for their synthesis and the plasticity of the synthesis in a plant cell are highlighted. The involvement of PCs in the plant breathing, photosynthesis, oxidation-reduction processes and regulation of the plants physiological state are discussed.

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Ацилгомосеринлактоны (АГЛ)-класс молекул медиаторов, координирующих активность клеток в популяции грамотрицательных бактерий. АГЛ синхронизируют индивидуальные клеточные геномы, благодаря чему бактериальная популяция функционирует как многоклеточный организм. Они обеспечивают дистанционный сигналинг между бактериями-колонизаторами фитосферы, что позволяет популяции реагировать на внешний сигналинг и устанавливать симбиотические либо антагонистические отношения с растением-хозяином (A.R. Stacy с соавт., 2018; А. Shrestha с соавт., 2020). Ауторецепция количественных параметров бактериальной популяции называется «quorum sensing» (QS) (R.G. Abisado с соавт., 2018). QS-системы образуют сигнальные молекулы аутоиндукторы, легко проникающие из клеток в окружающую среду и обратно в клетку (M.B. Miller с соавт., 2001; B. Bassler, 2002). Системам QS принадлежит ключевая роль в регуляции метаболических и физиологических процессов, происходящих в бактериальной клетке (M. Frederix с соавт., 2011; M. Whiteley с соавт., 2017). Бактериальный сигналинг воспринимается эукариотами, которые образуют симбиоз с микробными сообществами (S.T. Schenk с соавт., 2015; Л.М. Бабенко с соавт., 2016, 2017). Рост и развитие растения, ассимиляция питательных веществ, стрессоустойчивость во многом определяются характером такого взаимодействия (H.P. Bais с соавт., 2006; R. Ortíz-Castro с соавт., 2009; S. Basu с соавт., 2017). Управлять бактериальным сигналингом растению позволяет система «quorum quenching» (QQ) (N. Calatrava-Morales с соавт., 2018), механизм действия которой состоит в подавлении растительными метаболитами синтеза АГЛ, конкуренции с АГЛ за связывание с рецепторными белками, репрессии QS-контролируемых генов (H. Zhu с соавт., 2008; R. Sarkar с соавт., 2015). Однако в настоящее время молекулярные механизмы, с помощью которых растения реагируют на бактериальный сигналинг, до конца не выяснены. Часть метаболитов АГЛ-сигналинга охарактеризованы, однако их роль в химическом взаимодействии партнеров в большинстве случаев требует дальнейшего изучения. Показано, что явление QS и его участники причастны к регуляции взаимодействий между про-и эукариотами, в том числе к формированию биопленок, синтезу фитогормонов, трансферу плазмид, продукции факторов вирулентности, биолюминесценции, споруляции, образованию клубеньков (Л.М. Бабенко с соавт., 2017). Различия в строении молекул обеспечивают распознавание бактериями собственных АГЛ и отделение чужеродных. Перенос АГЛ от бактерии к растению-хозяину осуществляется при помощи мембранных везикул (M. Toyofuku, 2019). В последние годы активно изучаются генетика, геномика, биохимия и сигнальное разнообразие молекул QS. Регулирование функций ризосферынаиболее динамичного сайта взаимодействия растения и ассоциированной с ним микрофлоры с участием АГЛ приобретает особое значение при разработке новых биотехнологических подходов, направленных на повышение урожайности и стрессоустойчивости аграрных культур. Одна из эффективных технологий повышения устойчивости к биотическим и абиотическим стрессам-предпосевна...

In today’s wheat production, the trends focused on the revival, selection and implementation of forgotten regional grain crops, the so-called "antique" cereals, have been clearly identified. One of these is the ancient hexaploid species of wheat – spelt (Triticum spelta). One of the main reasons that have contributed to the revival of this type of wheat in recent years is its tolerance to growing conditions and capacity to endure the natural and climatic factors of the environment, which allows it to be grown without an excessive use of plant protection products. It is precisely because of this feature that hulled wheat is referred to as "environmentally friendly”. Spelt is capable of yielding stable crops without strict adherence to the production technology and may be a great alternative to soft wheat. The growth in demand for this crop is also due to a complex of economic and valuable traits inherited from its wild ancestors. This review analyzes and summarizes the information about the origin of spelt, presents biological characteristics, discusses the perspectives for using the species in breeding work when implementing interspecific hybridization and compares the structure and genome evolution. The achievements on the revival of spelt as an independent species and its use as a source of economic and valuable traits in breeding programs of crosses with soft wheat are highlighted, examples of successful use of the economic and valuable traits of spelt for the improvement and creation of new high-quality wheat varieties are presented. Data on this superiority of grain from this species over that of genetically close wheat species are presented. The varietals’ characteristics for spelt varieties of Ukrainian selection are given. Such important spelt characteristics as resistance to biotic and abiotic stressors, high quality grain composition and yield have been analyzed.