低温对红花脂肪酸组成和脂肪酸脱氢酶基因表达的影响

Effects of Low Temperature on Fatty Acid Composition and Gene Expression of Fatty Acid Desaturase in Safflower

为探测低温对红花微粒体和质体脂肪酸脱氢酶的影响,本研究分别采用GC-MS和RT-PCR测定了低温条件下两种基因型红花材料苗期不同组织部位脂肪酸含量和ω-6和ω-3基因的表达水平变化。研究发现,低温不同程度地提高了两种红花材料组织中不饱和脂肪酸的相对百分含量,但不同基因型红花材料的不同组织部位对低温响应情况有所不同,总体上PI470942材料根对低温不敏感,而叶片对低温较为敏感,而PI544021材料叶片对低温不敏感,茎对低温较敏感。此外,低温对不同材料脂肪酸脱氢酶基因表达及对同一基因型红花材料的不同组织部位的相关基因表达情况的影响均有较大差异。低温显著促进了PI470942材料叶片脂肪酸脱氢酶基因的表达,而对根中脂肪酸脱氢酶基因变化影响不显著,而低温显著促进了PI544021材料根中脂肪酸脱氢酶基因的表达,而对叶片影响较小。另外,低温对脂肪酸含量的调节既有转录水平又有转录后水平,且这种调节具有组织差异性。低温主要在转录水平上调节根和叶片中脂肪酸含量变化,而主要在转录后水平上调节茎中脂肪酸含量变化。本研究为进一步探究低温对脂肪酸脱氢酶的调控情况提供了参考。

To study the effects of low temperature on fatty acid desaturase from microsome and plasmid,GC-MS was applied to detect the fatty acid contents in different tissues of safflower in seedling stage of two genome types under low temperature,and fluorogenic quantitative PCR was used to measure the expression changes ofω-6 andω-3 genes in this research.The results showed that the relative percentage contents of unsaturated fatty acid in two safflower materials increased in different degrees under low temperature,but different responses were existed in different tissues of safflower materials in different genotypes under low temperature.As a whole,the roots of genotype PI470942 and leaves of genotype PI544021 were not sensitive to low temperature,and the leaves of genotype PI470942 and stems of genotype PI544021 were sensitive to it.In addition,great differences existed in relative expression levels of fatty acid desaturase genes in different materials and different tissues from the same genotype safflower material under low temperature.Low temperature significantly increased the expression level of fatty acid desaturase in PI470942 leaves but had no significantly change of that in roots.However,the expression levels of fatty acid desaturase genes in PI544021 roots increased significantly and were not changed significantly in leaves.Besides,the contents of fatty acid were regulated at transcriptional and post-transcriptional level,and the regulation patterns had tissues variabilities.The contents of fatty acid in roots and leaves were regulated primarily at the transcriptional level and the that in stems were regulated primarily at post-transcription level under low temperature.This research could provide reference for further studying the regulation of fatty acid desaturase under low temperature.