‘檀桥’板栗雌雄花不同发育时期转录组分析

Transcriptome analysis of male and female flowers of Castanea mollissima‘Tanqiao’at different development stages

【目的】板栗Castanea mollisima为我国重要的木本粮食树种,其果实营养价值极高。花发育是板栗产量形成的重要基础。因此,研究板栗雌雄花不同发育时期的基因表达变化,挖掘板栗花发育关键基因,对进一步完善成花机理具有重要的意义。【方法】以不同时期‘檀桥’板栗雌雄花为材料,采用石蜡切片技术观察雌雄花发育进程,利用转录组测序、生物信息学分析以及荧光定量PCR等方法,筛选‘檀桥’板栗雌雄花发育的相关差异基因。【结果】细胞学观察雌花为雌蕊原基分化期和开放期,雄花为花药发育期和开放期。转录组测序共得到90.16 Gb Clean Data,雌花不同发育时期共获得1094个DEGs,其中600个上调,494个下调;雄花不同发育时期共获得3407个DEGs,其中1847个上调,1560个下调;韦恩图显示两组间共有663个DEGs。雌花有3260条DEGs注释到GO数据库中,分为细胞组分、分子功能及生物学过程3大类42条通路;雄花注释到10196条DEGs分为3大类47条通路。KEGG富集分析显示雌雄花两组共有的差异基因显著富集在植物昼夜节律计划、淀粉和蔗糖代谢、类胡萝卜素生物合成代谢通路上;共筛选出69个植物昼夜节律计划、淀粉和蔗糖代谢以及激素信号转导相关差异表达基因。此外,WGCNA分析得到了2个hub基因BAM1、SAMT。【结论】光周期以及糖类化合物、激素信号转导相关基因PIF3、BAM1、SAUR等可能是‘檀桥’板栗成花关键基因。这些结果为深入研究‘檀桥’板栗花发育的分子机理奠定了理论基础。

【Objective】Chestnut(Castanea mollisima)is an important woody grain tree species in China,and its fruit has high nutritional value.Flower development is an important basis for Chinese chestnut yield formation.Therefore,to further improve the flowering mechanism in chestnut,studying the gene expression changes of male and female flowers at different development stages and excavating the key genes of flower development is of great significance.【Method】Using the female and male flowers of C.mollissima‘Tanqiao’at different development stages as materials,the development process of female and male flowers were observed by paraffin sectioning,and the related differential genes were Screened by transcriptome sequencing,bioinformatics analysis and quantitative PCR.【Result】Cytological observation showed that female flowers were in pistil primordium differentiation stage and blooming stage,and male flowers were in anther formation stage and blooming stage.Transcriptome sequencing obtained 90.16 Gb Clean Data,a total of 1094 DEGs of female flowers at different development stages were obtained,of which 600 genes were up-regulated and 494 genes were down regulated,respectively.A total of 3407 DEGs of female flowers at different development stages were obtained,of which 1847 genes were up-regulated and 1560 genes were down-regulated,respectively.There were 663 DEGs between the female and male flower by the Venn diagram.There were 3260 DEGs in female flowers annotated into GO database,divided into three categories:cellular components,molecular functions,and biological processes,with 42 pathways;while 10196 DEGs in male flowers were classified into 3 categories and 47 pathways.KEGG enrichment analysis revealed that the two groups were significantly enriched in plant circadian rhythm plan,starch and sucrose metabolism and carotenoid biosynthesis pathway.A total of 69 differentially expressed genes related to plant circadian rhythm plan,starch and sucrose metabolism and hormone signal transduction were screened.In addition,two hub genes BAM1 and SAMT were obtained by WGCNA analysis.【Conclusion】Photoperiod,carbohydrate,hormone signal transduction related genes PIF3,BAM1,SAUR,et al.may be the key genes for the flowering of C.mollissima‘Tanqiao’.These results laid a theoretical foundation for the further study of the molecular mechanism of flower development in C.mollissima‘Tanqiao’.