Methyl jasmonate vapors affect the composition and peroxidation of major fatty acids in common buckwheat seedlings

The effect of methyl jasmonate (MJ) vapors on the composition and peroxidation of major fatty acids in the organs of common buckwheat seedlings was investigated. The composition of fatty acids in the hypocotyl and cotyledons of seedlings changed significantly under exposure to MJ vapors in closed jars. Four-day exposure to MJ led to a significant reduction in the concentrations of stearic, linoleic, and linolenic acids in the hypocotyl, whereas oleic acid levels increased approximately 3.5-fold. A decrease in stearic acid levels and an increase in the content of linolenic acid were noted in cotyledons, whereas oleic acid levels decreased in roots. Seven-day exposure to MJ vapor caused a further reduction in stearic acid content and an increase in oleic acid and linoleic acid levels in the hypocotyl. At the same time, the linoleic acid content of roots and linolenic acid levels in cotyledons were doubled, but a 5-fold reduction in linolenic acid concentrations was observed in roots. Methyl jasmonate intensified fatty acid peroxidation in cotyledons after 4 and 7 days and in roots after 4 days of exposure. Peroxidation was inhibited in the hypocotyl and roots after 7 days. The noted changes in the composition and peroxidation of fatty acids are probably indicative of senescence in buckwheat seedlings under the influence of MJ. Senescence seems to proceed faster in cotyledons than in other organs of buckwheat seedlings.