高粱缺氮特异诱导基因SbMYB-like克隆及功能分析  

Cloning and Functional Analysis of Nitrogen Deficiency Induced Gene SbMYB-like in Sorghum

作　　者：朱振兴[1] 李丹[1] 陆晓春[1] ZHU Zhen-xing;LI Dan;LU Xiao-chun(Liaoning Province Key Laboratory of Crop Molecular Improvement/Sorghum Institute of Liaoning Academy of Agricultural Sciences,Shenyang 110161)

机构地区：[1]辽宁省作物分子改良重点实验室/辽宁省农业科学院高粱研究所,沈阳110161

出　　处：《植物遗传资源学报》2023年第1期252-260,共9页Journal of Plant Genetic Resources

基　　金：辽宁省优秀青年自然基金(2021-YQ-04);中国博士后面上基金(2021M693848);国家谷子高粱产业体系(CARS-06-14.5-A3)。

摘　　要：高粱是全球重要的五大粮食作物之一,具有耐瘠薄、耐旱等特性。氮元素是保障作物稳产、高产的三大重要养分元素之一。氮信号途径相关基因研究在高粱中基本不清楚,挖掘缺氮诱导基因,有助于解析高粱氮素吸收、利用相关分子通路。本研究克隆了先前在高粱BTX623苗期缺氮、缺磷及缺钾表达谱中筛选出的1个地上部分特异受缺氮诱导的MYB-related转录因子家族成员SbMYB-like基因Sb03g030330,该基因编码蛋白预测定位于细胞核。高粱中组织表达qRT-PCR分析表明SbMYB-like基因在根、茎、花中表达较低,主要在叶片中表达。进化树分析表明该基因与玉米、二穗短柄草中同源基因亲缘关系相对较近。通过qRT-PCR在二穗短柄草中验证了该基因同源基因地上部分受缺氮诱导的特性。在高粱BTX623品种中分离并克隆了SbMYB-like基因,构建超表达载体,转化拟南芥获得了超表达株系。通过缺氮和缺磷处理,测定野生型和超表达纯系植株主根长度和开花时间,结果表明该基因在促进根系伸长和开花方面有重要的作用,但此促进作用并不依赖于外源氮素水平。本研究为高粱缺氮响应分子途径解析提供了基础数据。Sorghum is the fifth most important cereal crops in the world and shows strong tolerance to low-fertility soil and drought. Nitrogen is one of the three essential nutrients which ensures stable and high crop yield. The nitrogen signaling pathways in sorghum remains largely unknown. Deciphering the nitrogen deficiency inducible genes will help to analyze the molecular pathways involved in sorghum nitrogen absorption and utilization. A member of MYB-related transcription factor family, SbMYB-like(Sb03g030330) was cloned based on the global gene expression profiles of sorghum seedlings under nitrogen, phosphorus, and potassium deficiency conditions. SbMYB-like was found being inducible by nitrogen deficiency in shoots, and its deduced protein SbMYB-like was predicted to be localized in the nucleus. qRT-PCR analysis showed that the transcripts of SbMYB-like were lower in roots, stems and flowers, whereas abundant in leaves. Phylogenetic tree analysis indicated that SbMYB-like was closely grouped with its homologs in maize and Brachypodium P. Beauv., and both homologs were inducible under nitrogen deficiency condition by qRT-PCR. The SbMYB-like coding sequence from sorghum BTX623 variety was isolated and transformed into Arabidopsis Heynh. driven by a constitutive promoter. The growth parameters of Sb MYB-like over-expressing plants under nitrogen and phosphorus deficiency conditions were measured. The results showed that SbMYB-like was involved in root elongation and flowering independent of the environmental nitrogen levels. Collectively, this study provided basic data for analysis molecular mechanism of sorghum response to nitrogen deficiency.

关 键 词：MYB-related 转录因子 缺氮 开花 根伸长 高粱 

分 类 号：S514[农业科学—作物学]