木薯C4 途径对温度应答的蛋白质调控研究

Cassava is a potential bioenergy and food crop, which has characteristics of high photosynthesis and high starch accumulation. It has two kinds of important enzyme-complexes including RuBPCase and PEPCase, but the efficiency of photosynthesis is significant differences between cassava different germplasms. So far, the effect of PEPCase in C4 photosynthetic pathway on the photosynthetic efficiency is little reported. In this project, different cassava cultivars in response to different temperatures will be employed to establish the proteome expressed maps of chloroplasts. The differential proteins between different cultivars will be investigated through Delta2D software and identified by MALDI-TOF-TOF-MS/MS. The protein-protein interaction between PEPCase and differential expressed proteins will be detected by Pull-down technique. In order to understand the photosynthesis efficiency, we detected the expression level of PEPCase under temperature treatments using western blotting method and reveal the relativity involved in the net photosynthesis and PEPCase. Furthermore, the biological network of protein-protein interaction regarding PEPCase regulation in cassava photosynthesis will be established through Pathway Studio software for providing a new clue for screen out a high photosynthesis efficient varieties in cassava breeding.

木薯是一种生物质能源与粮食作物，具有高光效和高淀粉积累的特性,叶片存在光合作用C3和C4途径的两种酶系（RuBPCase和PEPCase）,但不同品系间的光合效率差异较大，迄今为止关于C4途径对木薯光合作用的调控研究尚未见报道。本项目利用蛋白质组学方法构建不同温度条件下不同木薯品系叶绿体的蛋白质表达谱并进行蛋白质差异表达分析，差异表达蛋白质鉴定采用MALDI-TOF-TOF-MS/MS质谱法。通过免疫共沉淀方法明确差异表达蛋白质与木薯C4途径关键酶PEPCase的相互作用关系。利用Western blot方法分析不同温度条件下PEPCase的表达水平及叶片光合速率的相关性；结合不同温度条件下叶片净光合效率的差异，利用Pathway Studio软件构建C4途径PEPCase对温度应答的蛋白质互作生物调控网络；阐述C4途径PEPCase对温度的应答机理，为木薯高光效种质的创制提供新思路。

木薯是一种生物质能源与粮食作物，具有高光效和高淀粉积累的特性,叶片存在光合作用C3和C4途径的两种酶系（RuBPCase和PEPCase）,但不同品系间的光合效率差异较大，迄今为止关于C4途径对木薯光合作用的调控研究尚未见报道。本项目利用iTRAQ技术结合蛋白质组双向电泳方法研究不同温度条件下不同木薯品系叶绿体的蛋白质表达谱并进行蛋白质差异表达分析，通过GO富集方法明确差异表达蛋白质与木薯C4途径关键酶PEPCase的相互作用蛋白质，发现差异表达的蛋白质中与氧化还原酶和四吡咯相关功能的蛋白分别占15%和10%，并在KEGG平台基于String软件构建了C4光合途径PEPCase对温度应答的蛋白质互作生物调控网络，发现通路中4.1.1.39，4.1.2.13和2.7.2.3三个蛋白调节叶片对温度响应的关键蛋白。