卷叶木薯及其突变体叶片的比较转录组分析

Comparative transcriptome profiling of leaf in curled-leaf cassava and its mutant

为解析卷叶木薯叶片异常发育的分子调控机制及代谢通路,以正常卷叶木薯叶片(JY)、突变株展叶叶片(ZY)和突变株卷叶叶片(BJ)为试验材料,基于转录组测序(RNA-seq)数据进行生物信息学分析。DESeq差异分析结果显示,ZY vs BJ、JY vs ZY、JY vs BJ分别有327(255个上调,72个下调)、1085(337个上调,748个下调)、689(381个上调,308个下调)个DEGs,有19个DEGs是3个比较组共同表达的。GO功能分析显示,DEGs在刺激反应、膜的组成部分、跨膜转运蛋白活性等途径差异显著。KEGG富集分析显示,DEGs在苯丙素的生物合成、植物激素信号转导、内质网中的蛋白加工等通路较为活跃。进一步对变异展叶与同株的卷叶和其他植株正常卷叶的DEGs分析发现集中富集到苯丙素的生物合成途径、淀粉和蔗糖代谢、植物激素信号转导,这可能是展叶突变体形成的关键因子。展叶与卷叶差异基因的主要KEGG代谢通路有9条,重要差异基因有9个。对不同类型叶片显微分析发现突变后的展叶木薯上表皮细胞层数增加、海绵组织结构变得疏松、维管束细胞减少。研究结果为进一步理解木薯叶片异常发育的分子机制提供了理论指导,为木薯遗传改良、种质创新挖掘提供基因资源和改良策略。

The objective of this study is to elucidate the molecular regulatory mechanisms and metabolic pathways underlying the abnormal development in the leaf of curled-leaf cassava.Normal curled cassava leaf(JY),mutant expanded leaf(ZY),and mutant curled leaf(BJ)were used as the experimental materials,and bioinformatics analysis was conducted based on transcriptome sequencing(RNA-seq)data.DESeq differential analysis showed that there were 327(255 up-regulated,72 down-regulated)DEGs for ZY vs BJ,1085(337 up-regulated,748 down-regulated)DEGs for JY vs ZY,and 689(381 up-regulated,308 down-regulated)DEGs for JY vs BJ,and 19 DEGs were co-expressed by three comparative groups.GO functional analysis showed that DEGs had significant differences in the pathways of stimulus response,components of membranes,and transmembrane transporter protein activity.KEGG enrichment analysis indicated that the DEGs were more active in pathways such as phenylpropanoid biosynthesis,phytohormone signaling,and protein processing in the endoplasmic reticulum.Further analysis of the DEGs in the mutated leaf expansion,curled leaves of the same plant,and normal curled leaves of other plants,demonstrated that the DEGs were concentrated in the phenylpropanoid biosynthesis pathways,starch and sucrose metabolism,and plant hormone signal transduction,which may be the key factors causing leaf expansion mutants.There were 9 main KEGG metabolic pathways and 9 important differentially expressed genes involved in leaf expansion and leaf curling.Microscopic analysis of different types of leaf revealed an increase in the number of epidermal cell layers,a loosening of sponge tissue structure,and a decrease in vascular bundle cells in mutated expanded cassava.The results of this study provide theoretical guidance for further understanding the molecular mechanisms underlying the abnormal development of cassava leaf,as well as genetic resources and improvement strategies for cassava genetic improvement and germplasm innovation.