棉花4个脂肪酸合成相关基因的克隆和表达特征分析

Molecular Cloning and Expression Analysis of Four Novel Fatty Acid Synthesis Related Genes in Gossypium hirsutum L.

脂肪酸合成相关代谢在控制油的合成和抗非生物胁迫中均起着重要作用,其脂肪酸合成相关基因的时空表达水平直接影响油的含量和脂肪酸合成相关酶的活性。本研究克隆了4个脂肪酸合成相关基因,分别命名为GhKASII、GhKASIII、GhFAD和GhGPAT,其中GhKASIII、GhFAD和GhGPAT基因cDNA全长通过电子克隆和同源克隆得到。而GhKASII通过筛库和5′RACE途径得到。组织表达分析表明,上述4个基因在根、茎、叶及纤维发育不同时期均有表达,属于组成性表达基因。其中GhKASII、GhKASIII在25 DPA种子中表达量最高,GhGPAT在0 DPA胚珠和15 DPA纤维中表达量很高,GhFAD在0 DPA胚珠,15 DPA种子,20 DPA纤维中表达量均很高。不同非生物胁迫的诱导表达分析表明,上述4个基因均不同程度被茉莉酸甲酯,ABA,创伤和冷害等逆境诱导表达。

Metabolism related to fatty acid synthesis plays an important role both in regulating oil biosynthesis and in plant abiotic stress tolerance.The spatial and temporal expression level of genes related to fatty acid synthesis influences the oil content and enzymes activity for fatty acid synthesis.In this study,four novel genes related to fatty acid synthesis,designated GhKASII,GhKASIII,GhFAD,and GhGPAT,were first isolated from upland cotton,respectively.The cDNA full-length of GhKASIII,GhFAD and GhGPAT were obtained by combining homologic cloning and in sillico cloning,while GhKASII was obtained by screening cDNA library and 5′RACE technique.The expression pattern analysis of different tissues and organs revealed that the transcripts of these genes were widely distributed in all the tested tissues and organs.GhKASII and GhKASIII showed the highest expression level in seeds at 25 DPA（days post anthesis）,however,GhGPAT in 0 DPA ovules and 15DPA fiber tissues and GhFAD in 0 DPA ovules,15 DPA seeds and 20 DPA fibers,respectively.Further,the analysis of expression induced by abiotic treatments indicated that the genes were differentially regulated under wounding,methyl jasmonate（MeJA）,cold and ABA（abscisic acid） treatments.The study will pave a way to develop further research in oil improvement of cotton seed and resistance to abiotic stress in cotton.