For immobile plants, the main means of protection against adverse environmental factors is the biosynthesis of various secondary (specialized) metabolites. The extreme diversity and high biological activity of these metabolites determine the researchers’ interest in plants as a source of therapeutic agents. Oxylipins, oxygenated derivatives of fatty acids, are particularly promising in this regard. Plant oxylipins, which are characterized by a diversity of chemical structures, can exert protective and therapeutic properties in animal cells. While the therapeutic potential of some classes of plant oxylipins, such as jasmonates and acetylenic oxylipins, has been analyzed thoroughly, other oxylipins are barely studied in this regard. Here, we present a comprehensive overview of the therapeutic potential of all major classes of plant oxylipins, including derivatives of acetylenic fatty acids, jasmonates, six- and nine-carbon aldehydes, oxy-, epoxy-, and hydroxy-derivatives of fatty acids, as well as spontaneously formed phytoprostanes and phytofurans. The presented analysis will provide an impetus for further research investigating the beneficial properties of these secondary metabolites and bringing them closer to practical applications.

12-Oxophytodienoate reductase is the enzyme involved in the biosynthesis of phytohormone jasmonates, which are considered to be the major regulators of plant tolerance to biotic challenges, especially necrotrophic pathogens. However, we observe compromised tolerance to the necrotrophic fungal pathogen Botrytis cinerea in transgenic hexaploid bread wheat and tetraploid emmer wheat plants overexpressing 12-OXOPHYTODIENOATE REDUCTASE-3 gene from Arabidopsis thaliana, while in Arabidopsis plants themselves, endogenously produced and exogenously applied jasmonates exert a strong protective effect against B. cinerea. Exogenous application of methyl jasmonate on hexaploid and tetraploid wheat leaves suppresses tolerance to B. cinerea and induces the formation of chlorotic damages. Exogenous treatment with methyl jasmonate in concentrations of 100 µM and higher causes leaf yellowing even in the absence of the pathogen, in agreement with findings on the role of jasmonates in the regulation of leaf senescence. Thereby, the present study demonstrates the negative role of the jasmonate system in hexaploid and tetraploid wheat tolerance to B. cinerea and reveals previously unknown jasmonate-mediated responses.

The objective of this study was to analyze the fatty acid composition of five strains from the genera Chlorella, Micractinium, and Meyerella and conduct an initial assessment of their biotechnological potential. It was found that the strain C. vulgaris VKM Al-335 is a good producer of palmitic acid, the Micractinium strains VKM Al-332 and VKM Al-343 are rich in ω-3 fatty acids, whereas the Meyerella strains VKM Al-346 and VKM Al-428 are producers of ω-6 fatty acids. A comparison of the biotechnological potential of algae with that of higher plant leaves (wheat) demonstrates that algal fatty acids exhibit greater diversity, although it is inferior to wheat leaves in terms of polyunsaturated and ω-3 fatty acids. Correlation analysis showed that when only straight-chain fatty acids were considered, the strains were distributed on the principal component analysis plot in accordance with their genetic relationships. However, when the entire fatty acid profile, inclusive of minor branched-chain and cyclic fatty acids, was analyzed, the algae distribution was in accordance with the environmental conditions in the original habitat, suggesting a possible connection between branched-chain and cyclic fatty acids and microalgae adaptability to environmental temperature conditions.

The transformation protocol based on the dual selection approach (fluorescent protein and herbicide resistance) has been applied here to produce transgenic plants of two cereal species, emmer wheat and bread wheat, with the goal of activating the synthesis of the stress hormone jasmonates by overexpressing ALLENE OXIDE SYNTHASE from Arabidopsis thaliana (AtAOS) and bread wheat (TaAOS) and OXOPHYTODIENOATE REDUCTASE 3 from A. thaliana (AtOPR3) under the strong constitutive promoter (ZmUbi1), either individually or both genes simultaneously. The delivery of the expression cassette encoding AOS was found to affect morphogenesis in both wheat species negatively. The effect of transgene expression on the accumulation of individual jasmonates in hexaploid and tetraploid wheat was observed. Among the introduced genes, overexpression of TaAOS was the most successful in increasing stress-inducible phytohormone levels in transgenic plants, resulting in higher accumulations of JA and JA-Ile in emmer wheat and 12-OPDA in bread wheat. In general, overexpression of AOS, alone or together with AtOPR3, negatively affected leaf lamina length and grain numbers per spike in both wheat species. Double (AtAOS + AtOPR3) transgenic wheat plants were characterized by significantly reduced plant height and seed numbers, especially in emmer wheat, where several primary plants failed to produce seeds.

This article describes the negative effects of exogenously applied and endogenously produced jasmonates in the tolerance of bread wheat ( Triticum aestivum L.) plants of the Saratovskaya-60 cultivar to excessive light conditions. While no significant effect of jasmonates on the variable chlorophyll fluorescence parameters is evident under moderate and low light conditions, the negative effect of jasmonates at high light intensities is evident on a “rapid light curve” of methyl jasmonate (MeJA)-treated plants and transgenic plants Tr-20 overexpressing 12-OXOPHYTODIENOATE REDUCTASE 3 ( AtOPR3 ), a jasmonate biosynthesis gene from Arabidopsis thaliana . The analysis of fast chlorophyll fluorescence kinetics with high-time resolution (OJIP test) confirmed the difference between Tr-20, MeJA-treated and mock treated ‘Saratovskaya-60’. Two hours of plant leaves incubation under photoinhibitory light induce clearly visible changes in OJIP kinetics, and these changes are more pronounced in MeJA-treated and Tr-20 leaves as lower values of kinetic transient points J, I, and P. Subsequent two-hour incubation under low light leads to an almost complete recovery of the OJIP kinetics in leaves of mock treated ‘Saratovskaya-60’ leaves, while only partial recovery is observed in the leaves of MeJA-treated and Tr-20 plants. The transgenic line Tr-3, which under high light conditions does not accumulate more jasmonates than non-transgenic parental line, does not differ in tolerance to photoinhibition from the non-transgenic plants, confirming that the increased level of jasmonates is necessary to compromise the tolerance to photoinhibition. Analysis of stress hormones revealed the role of jasmonates in modulating the level of abscisic acid and salicylic acid during wheat leaves adaptation to high-light conditions. The data obtained lay the foundation for further studies of complex hormonal cross-talk in wheat leaves under light stress conditions.