基于三代测序技术的植物信号通路相关基因在胡杨异形叶发生中的功能分析

Role Analysis of Plant Signal Pathway Related Genes in Populus euphratica Heterophyll Morphogenesis Based on TGS

胡杨异形叶发生的分子机制目前仍不清楚。为了探究胡杨不同叶形的发生机制,本研究利用三代测序(TGS)结合二代测序技术,完善了胡杨的转录组数据,建立了胡杨条形叶、披针形叶、卵圆形叶和宽卵形叶的基因表达谱,并进一步分析了胡杨异形叶发生过程中植物信号通路相关基因的表达模式和作用。结果表明,胡杨叶组织中共有59004个mRNA,其中新发现的mRNA有9328个;根据胡杨中全部mRNA的表达趋势将其分为27种模式,其中两个模式(模式4和模式23)中总计4284个基因表达趋势与叶形指数变化完全一致或完全相反,是胡杨异形叶发生相关基因;胡杨异形叶发生相关基因中,参与脱落酸(ABA)信号通路的基因有9个、生长素(IAA)信号通路的有29个、细胞分裂素(CTK)信号通路的有10个、赤霉素(GA)信号通路的有3个,这些基因的功能和表达趋势表明,大多数促进这些信号通路的基因从条形叶到宽卵形叶表达量持续上调,大多数抑制这些信号通路的基因的表达量则持续下调。本研究结果表明,胡杨从条形叶到宽卵形叶的转变与ABA、IAA、CTK和GA信号通路的活跃程度增加密切相关,这些发现对揭示胡杨异形叶形成的分子机制和胡杨培育保护都有重要的意义。

The molecular mechanism of heterophyll morphogenesis in Populus euphratica remains unclear.In order to explore the morphogenesis mechanism of a P.euphratica heterophyl,in this study,the transcriptome data of P.euphratica was improved by using third-generation sequencing(TGS)combined with second-generation se quencing technology,and the expression profiles of linear,lanceolate,oval and broadly oval leaves of P.euphratica were established.Furthermoe,the expression patterns and functions of genes related to plant signaling pathways during the development of heteromorphic leaves of P.euphratica were further analyzed.It found that there were 59004 mRNAs in the leaves of P.e uphratica,among which 9328 were newly discovered.According to the expression trends of all mRNAs in P.euphratica,they were divided into 27 models,in two of the patterns(model 4 and model 23),the expression trend of 4284 genes were completely consistent with or opposite to the change of leaf shape index,which were identified as the genes related to P.euphratica heterophyll morphogenesis.There were 9 genes involved in abscisic acid(ABA)signaling pathway,29 genes involved in auxin(IAA)signaling pathway,10 genes involved in cytokinin(CTK)signaling pathway,and 3 genes involved in gibberellin(GA)signaling pathway.The functions and expression trends of these genes indicated that,from linear to broad oval leaves,most of genes promoting these signaling pathways are up-regulated,while most of the genes inhibiting these signaling pathways are down-regulated.The results of this study indicate that the transition from linear to broad oval leaves of P.euphratica is closely related to the increased of ABA,IAA,CTK and GA signaling pathways.These findings have important implications for the molecular mechanism of heterophyll-shaped leaf formation and the conservation of P.euphratica.