甜瓜雄性不育两用系转录组测序与激素含量研究

Study on the Transcriptome Sequencing and Hormone Content in Male Sterile and Fertile Plants in Melon(Cucumis melo L.)

为了从分子及生理生化水平探讨甜瓜雄性不育发生过程中内源激素(生长素、赤霉素、茉莉酸、水杨酸)与花粉败育的相关性,利用雄性不育两用系对甜瓜可育株与不育株2 mm花蕾雄蕊进行转录组测序,筛选内源激素相关差异表达基因,结合实时荧光定量分析以鉴定差异基因表达量,并对雄性不育株与可育株的花蕾内源激素含量进行测定。结果显示:转录组测序共发现334个差异表达基因,对差异表达基因进行GO功能分析显示,共有273个基因归属于生物合成、分子功能和细胞组分三大分支,其中与内源激素相关的差异基因为7个,其中2个差异表达基因为水杨酸甲基转移同源基因,3个为生长素相关表达基因,赤霉素相关表达基因和茉莉酸相关表达基因各1个;qRT-PCR验证表明,与生长素相关的基因和吲哚-3-乙酸合成相关基因在雄性不育株花蕾中的表达量均高于可育株的表达量,而赤霉素、茉莉酸和水杨酸相关表达基因在雄性不育株花蕾中的表达量则是低于可育株中的表达量。激素含量的测定结果显示赤霉素和生长素含量可育株高于不育株,茉莉酸甲酯与水杨酸的含量不育株高于可育株。研究结果表明植物激素类相关基因通过间接方式参与雄性不育发生过程,同时多个激素基因之间存在相互拮抗,代谢途径复杂;茉莉酸甲酯和水杨酸含量过度积累可能与雄性不育的发生相关。

In order to explore the relationship between the occurrence of male sterility in melon （Cueumis melo L.） and the metabolism of hormone （Indole-3-acetic acid IAA, Gibberellin GA, Jasmonic acid methyl esterfrom JaMe, and Salicylic acid SA）in the transcriptional and physiological and biochemical level, the RNA-seq by the stamens of the fertile and sterile plants of 2mm buds were conducted in the present study, deferentially expressed genes related to the hormone were screened, the real time fluorescence quantitative analysis in 2 mm diameter stage of microspore development in MS and FS plants were carried out to identify the expression pattern of differential genes, hormone contents were also investigated in floral buds of male sterile and fertile plants. The results showed that a total of 334 differentially expressed genes were found out, 273 genes in transcriptome sequencing, GO function analysis showed these genes were involved in the three branches including the biosynthesis, molecular function and cell component. Among them, 7 genes related to the hormone including 2 JaMe genes, 3 IAA-related genes, 1 GA-related gene and 1 SA-related gene. qRT- PCR validation showed that fertile plants＇ expression of IAA related genes and Indole-3-acetic acid related genes were higher than sterile plants, on the contrary, fertile plants＇ expression of GA, JaMe and SA related gene were lower than sterile plants, the hormone content of GA and IAA in male fertility plants were higher than that of sterility plants, while JaMe and SA content in male sterility were higher than fertility lines.The results supposed that the hormone related gene participate in occurrence of male sterility with indirect way, different hormone related gene interact with each other, and the pathway was complex, the excessive accumulation of JaMe and SA might relate to male sterility.