Effects of accelerated aging upon the lipid composition of seeds from two soft wheat varieties from Morocco

Abstract

Effects of accelerated aging upon the lipid composition of seeds from two soft wheat varieties from Morocco.The lipid composition of the seeds from two soft wheat varieties (Triticum aestivum, cv. Marchouche and Mahdia) were analyzed before and after accelerated aging. Eight days of accelerated aging resulted in a total inhibition of seed germinability as well as a decrease in their total and especially unsaturated fatty acid contents. Oleic and linoleic acid contents decreased particularly in the phosphatidylcholine of the seeds from both varieties. The proportion of polar lipids also decreased after aging as compared to neutral lipids: a 5.8% and 7.2% decrease in polar lipids was e observed in Mahdia and Marchouche cultivars, respectively. In the neutral lipids of the seeds from the Marchouche variety, the percentage of free fatty acids increased whereas the triacylglycerols decreased. After aging, the fatty acid compositions of all lipid classes were modified in the same manner as total fatty acid compositions. Among polar lipids, phospholipid proportions were particularly small, especially the phosphatidylcholine percentages with an 18.1% and 19.1% decrease in Mahdia and Marchouche varieties, respectively. In contrast, MGDG percentages increased, especially in the seeds from the Marchouche variety. A 15.5% increase was noticed when compared with seeds which were not aged. At the same time, the DGDG percentage showed a 16.6% decrease after accelerated aging of the seeds from the Marchouche variety. From these results we concluded that the lipid content decrease observed in seeds after accelerated aging could be linked to a loss in the germination and vigor of wheat seeds.

Integrated Transcriptomic and Metabolomic Analyses Identify Critical Genes and Metabolites Associated with Seed Vigor of Common Wheat

“…As the final products of genome expression, metabolites directly determine the biochemical characteristics of a cell or tissue [ 25 ], which allows metabolomic data to be used to explain the biochemical mechanisms underlying artificial seed aging between wheat cultivars. Meanwhile, integrated transcriptomic and metabolomic analysis allows for the more precise representation of gene-to-metabolite networks [ 26 , 27 , 28 ] and, thus, is an effective method for deciphering the mechanisms involved in artificial seed aging. In this study, we combined transcriptomic and metabolomic analyses to generate dynamic maps of artificial aging processes involving wheat seeds, aiming to better understand the physiological mechanisms at the molecular and biochemical levels.…”

“…Lipid peroxidation has been proven to cause a loss of seed viability [ 28 , 29 , 30 , 31 ]. Lipid peroxidation products are always detected in seeds after artificially accelerated aging at high temperature and humidity levels, but are rarely detected in the early degradation process of naturally aged seeds.…”