杜仲雌花芽2个发育时期转录组分析

The Transcriptome Analysis of Female Floral Bud at Two Development Stages in Eucommia ulmoides

杜仲(Eucommia ulmoides)的果实是提取杜仲胶和杜仲籽油的重要原材料,在工业、医疗、食品等领域开发前景广阔。为了揭示雌蕊原基发育相关基因的表达情况,本研究以杜仲果用良种‘华仲6号’(Huazhong No.6)为材料,利用lllumina Hiseq X-10高通量测序平台,分别对花序原基分化期和雌蕊原基分化期的花芽进行转录组测序,通过生物信息学对2个发育时期的雌花芽转录组进行比较分析,筛选出与杜仲雌蕊原基发育相关的差异基因。结果显示,转录组测序共获得68.11 Gb数据,各样品的Clean reads与杜仲基因组进行序列比对,比对效率为91.59%~92.05%,同时2个发育时期共筛选出485个差异表达基因,其中219个差异基因在雌蕊原基分化期表达上调,266个表达下调。差异基因GO富集结果表明,花的发育、光周期现象、激素生物合成以及蛋白结合转录因子活性等相关的生物途径被富集。KEGG富集结果表明淀粉和蔗糖代谢、碳代谢、昼夜节律和植物激素信号转导等代谢通路被富集。结果表明光周期途径是诱导杜仲成花的重要途径,且雌蕊原基发育受碳水化合物、植物激素和其他代谢物质调控。本研究为杜仲花器官发育调控基因的挖掘提供了基础数据,也为果用杜仲的分子育种提供了参考。

The fruit of Eucommia ulmoides is rich in trans-1,4-polyisoprene and unsaturated fatty acids,which can be exploited for use in medical instruments,tires,cables,edible oil and other products.The transcriptomes of female floral buds of’Huazhong N o.6’at inflorescence primordium differentiation and pistil differentiation stages were sequenced by lllumina Hiseq X-10,aimed to elucidate the candidate genes involved in the pistil development of E.ulmoides.A total of 68.11 Gb clean data were obtained,91.59%~92.05%of the clean reads were mapped to the E.ulmoides reference genome.In addition,a total of 485 genes were considered to be expressed differentially(DEGs).It was found that 266 genes were significantly down-regulated and 219 genes were significantly up-regulated in the female flower buds at pistil differentiation stage.GO analysis of DEGs showed flower development,photoperiodism,hormone biosynthetic process and nucleic acid binding transcription factor activity and other process processes closely involved in stamen development were enriched.KEGG analysis showed the DEGs were enriched in starch and sucrose metabolism,carbon metabolism,plant hormone signal transduction and circadian rhythm-plant and other pathways associated with flower induction.The results indicated that photoperiodic was the most important pathway for the floral induction of E.ulcommia.In addition,the carbohydrates,plant hormone and other metabolic substance was also required in the process of male floral bud differentiation.It provides a significant reference for studying the genes involved in the floral organs and molecular breeding of E.ulcommia.