Effects of low temperature stress on rice (Oryza sativa L.) plastid ω-3 desaturase gene, OsFAD8 and its functional analysis using T-DNA mutants

Expression of two rice plastidial omega-3 desaturase genes, OsFAD7 and OsFAD8 under different temperatures has been investigated. Transcript levels of OsFAD7 increased at high temperature; while those of OsFAD8 increased at low temperatures. Fatty acid analysis of homozygous OsFAD8 T-DNA knockout mutant and wild type plants have exhibited changes in fatty acid composition after cold stress, thus confirming that OsFAD8 gene codes for omega-3 fatty acid desaturase activity at low temperature. Photosynthetic efficiency and recovery of OsFAD8 knockout mutants are significantly reduced after cold stress as compared to those of wild type plants. Characterization of OsFAD8 suggests that it has a functional role in maintaining levels of trienoic fatty acids and stress tolerance at low temperatures.