小麦直立叶突变体MtHS29的转录组分析

Transcriptome Aanalysis of Wheat Erect Leaf Mutant MtHS29

为解析小麦叶片直立的分子调控机制,以快中子辐射诱变获得的小麦直立叶突变体MtHS29及其野生型衡S29为材料,通过转录组分析挖掘与MtHS29叶片直立相关的差异表达基因。结果表明,突变体MtHS29的叶片相较于野生型衡S29存在不同程度的缺失,其中旗叶和倒二叶的叶枕、叶舌和叶耳全都缺失,叶片呈直立向上生长的状态。突变体MtHS29和野生型衡S29倒二叶、倒三叶和倒四叶的叶枕部位存在共同差异表达基因1567个,主要富集在植物激素信号转导、淀粉和蔗糖的生物合成、苯丙素的生物合成、内质网的蛋白质加工,以及氨基酸和核苷酸糖代谢等通路。进一步分析发现,参与细胞壁松弛的细胞壁主要成分合成相关基因、参与调控叶舌形成和叶夹角大小的生长素和油菜素内酯合成或信号转导相关基因,以及多个参与植物器官形态建成调控相关基因在突变体MtHS29中差异表达,与叶枕处近、远轴面细胞分裂和伸展活动减弱,以及突变体叶舌、叶耳和叶枕等结构的缺失密切相关。本研究为小麦株型育种提供了新的种质资源,也为阐明小麦直立叶形成的分子调控机制提供了一定的理论依据。

To elucidate the molecular mechanism of leaf erectness in wheat,this study analyzed the differentially expressed genes(DEGs)using the transcriptome sequencing in a wheat erect leaf mutant MtHS29,which was identified using fast neutron irradiation in the wild type cultivar Heng S29.The leaves from MtHS29 were observed with degrees of deficiency with leaf pillow,ligule and auricle,in which the flag leaf and the second leaf from top lacked all of these structures and their leaf angles approached to zero.A total of 1567 DEGs were found in the leaf pillow of the second,third and fourth leaves from top between MtHS29 and WT.These genes were enriched in the pathways of plant hormone signal transduction,starch and sucrose biosynthesis,phenylpropanoids biosynthesis,endoplasmic reticulum protein processing,and amino acid and nucleotide glucose metabolism,etc.A proportion of DEGs in MtHS29 were annotated closely associating to regulating the cell division and cell expansion in the proximal and distal axial surfaces of the leaf pillow,and to deficiency of leaf pillow,ligule and auricle in mutant.Several genes involved in the synthesis of cell wall components,synthesis and signal transduction of Auxin and Brassinosteroids,and regulation of plant organ morphogenesis were found.Collectively,this study provided new germplasm in wheat breeding for plant architecture,and insights for future deciphering the molecular mechanism of the erect leaf architecture in wheat.