Comparative changes in hardiness and lipid composition in two near-isogenic lines of wheat (spring and winter) grown at 2 °C and 24 °C

Abstract

Changes in total lipids, fatty acids, and lipid-P contents of two near-isogenic lines of wheat seedlings of the parental spring (D) and mutant winter (C) genotypes of Triticum aestivum L. var. Triple Dirk were compared during germination and growth at 2 °C and 25 °C. Qualitative and quantitative changes of total lipids, phospholipids, and linoleic and linolenic acids were detected in both genotypes when grown at 2 °C for 2–5 weeks as compared with seedlings of equivalent morphological development grown at 25 °C. These differences may be associated with the freezing resistance that developed when both genotypes were germinated at 2 °C. During the period of growth at 2 °C from week 5 to week 6, which coincided with the completion of the vernalization response in the winter genotype, higher levels of phospholipids were found in the winter genotype than in the spring genotype. In this same period, the lipids in the seedlings of the winter genotype grown at 2 °C showed much larger increases in contents of linoleic and linolenic acids than the lipids of the spring genotype grown at the same temperature. These changes may be the result of a gene-linked temperature-sensitive mechanism controlling desaturation of fatty acids and could possibly be associated with the vernalization process.