转录因子Cc-NAC基因调控苏丹草次生细胞壁合成的功能分析

Secondary cell wall synthesis study of Sorghum sudanense is the most impotant mean for improvement of forage’s biomass yield and digestibility, however, the knowledge of mechanism underlying Secondary cell wall synthesis of Sorghum sudanense is still limited. Tracheary elements reducing play important role in Secondary cell wall synthesis research, there are more Secondary cell wall synthesis study on the basis of tracheary elements reducing in model plant, such as Arabidopsis, but without any report on foragegrass. Previous studies, a system of tracheary elements induction in vitro of calli in sudangrass was established. To profile the gene expression patterns related Sorghum sudanense’s Secondary cell wall synthesis, a high-throughput RNA sequencing based on next generation sequencing technology were performed. A NAC transcription factors(Cc-NAC) were detected as candidate gene concerning secondary cell wall synthesis of sudangrass and full-length gene has been cloned. This project will explore the function and performing mechanism of CcNAC by Expression characterize, subcellular localization, transgenic technology and yeast two-hybrid system. The purpose of this project is to provide further insight into the molecular mechanism of secondary cell wall synthesis in Sorghum sudanense.

禾本科C4牧草苏丹草次生细胞壁合成的研究，对提高牧草生物质产量和家畜对牧草的消化率具有重要意义，但至今苏丹草等牧草的次生细胞壁合成分子机理尚不明确。管状分子体外合成体系是研究次生细胞壁机制的重要基础，在拟南芥等模式植物中已建立了相关的研究体系，但在牧草次生细胞壁研究中尚属空缺。本项目组前期高频率诱导苏丹草管状分子建立了苏丹草次生细胞壁体外合成体系，通过转录组测序和差异表达基因分析，挖掘并克隆了苏丹草次生细胞壁合成通路上的1个关键候选基因转录因子Cc-NAC。本项目拟以该基因为研究对象，通过表达特征分析、亚细胞定位分析、转基因验证和酵母双杂交的研究，明确该基因在苏丹草次生细胞壁合成中的作用，挖掘该基因的互作基因，为进一步阐明苏丹草次生细胞壁合成的分子机理奠定基础。

禾本科C4牧草苏丹草次生细胞壁合成的研究，对提高牧草生物质产量和家畜对牧草的消化率具有重要意义，但至今苏丹草等牧草的次生细胞壁合成分子机理尚不明确。本项目组前期高频率诱导苏丹草管状分子建立了苏丹草次生细胞壁体外合成体系，通过转录组测序和差异表达基因分析，挖掘并克隆了苏丹草次生细胞壁合成通路上的1个关键候选基因转录因子Cc-NAC，本项目以Cc-NAC基因为研究对象，通过表达特征分析、亚细胞定位分析、转基因验证和酵母双杂交的研究，明确了Cc-NAC在苏丹草的根、茎杆、叶、地下茎中均有表达，且在地下茎中的表达量最高，亚细胞定位在细胞核中，转基因验证发现，沉默表达Cc-NAC会抑制愈伤管状分子的形成，过量表达Cc-NAC会提高植株的木质素含量，酵母双杂交结果发现了26个Cc-NAC互做蛋白，其中有与植物木质合成通路相关的WRKY转录因子。本研究结果有助于阐明Cc-NAC作用于植物次生细胞壁合成的分子机理，为苏丹草次生细胞壁含量的遗传改良提供理论基础。