小麦叶绿素缺失突变体Mt6172及其野生型叶片蛋白质组学双向差异凝胶电泳分析

Proteomic Analysis of Leaves of the Chlorophyll-Deficient Wheat Mutant Mt6172 and Its Wild-Type through 2D-Difference Gel Electrophoresis

以空间环境诱变获得的小麦叶绿素缺失突变体Mt6172的白化苗及其野生型邯6172的叶片为材料,进行双向差异凝胶电泳(2D-DIGE)蛋白质组学分析。在1645个蛋白点中,发现100个差异1.5倍以上的蛋白点,对在分析胶中得到的85个点进行质谱鉴定,最终鉴定出29种差异蛋白的62个差异点,其中50个表达下调,12个表达上调,可分为10个功能群。表达下调的蛋白主要定位于叶绿体中,包括光系统I、光系统II、NAD(P)H脱氢酶复合体和ATP合酶的部分亚基,以及参与卡尔文-本森循环、糖代谢和应激反应的蛋白。非叶绿体蛋白中的大部分表达上调,主要参与抗氧化反应、转录激活和蛋白质折叠等途径。初步推断,光合作用主要蛋白复合体的缺失、叶绿体抗氧化能力的下降和叶绿体RNA转录后编辑途径受阻等可能是Mt6172白化致死的重要原因。

Two-dimensional difference gel electrophoresis （2D-DIGE） proteomic approach was used to identify differentially expressed proteins in the leaves of chlorophyll-deficient wheat mutant Mt6172 derived from space environment mutagenesis. A total of 1 654 protein spots were detected, of which 100 spots showed 1.5-fold or higher volume ratio in the leaves of Mt6172 or its wide-type H6172. Eighty-five spots subject to mass spectrometry and 62 spots representing 29 distinct proteins were identified and classified into 10 functional groups. Among these differential proteins, 50 were down-regulated and 12 were up-regulated. Most of the down-regulated proteins were located in the subcellular system of chloroplast, including the subunits of PSI, PSII, NAD（P）H dehydrogenase complex and ATP synthase, and the proteins involved in Calvin-Benson cycle, glucose metabolic proc- ess and stress responses. Compared to the proteins in chloroplast, the identified non-chloroplast proteins were mainly up-regulated, including the proteins involved in response to oxidative stress, transcriptional activation, and protein folding process. The results suggested that the early death of the albino phenotype of Mt6172 might result from the deficiency of main photosynthesis protein complexes, the decrease of chloroplast antioxidant capacity, and the obstacle of post-transcriptional modification process for chloroplast RNAs.