甘蔗与抗旱性相关差异蛋白质组分析

采用桶栽方式,对抗旱性强的F172和抗旱性弱的YL6甘蔗品种在苗期进行重度干旱胁迫处理后,应用蛋白质双向电泳技术进行差异蛋白质分析,分别找出差异显著的28和20个差异蛋白点,其中部分呈现上调表达,部分呈现下调表达,还有部分新增的蛋白点,因品种抗性不同而表现各异,F172叶片中的差异蛋白主要表现为上调表达,而YL6中大多表现为下调表达。在重度干旱胁迫下,抗旱性不同的甘蔗品种蛋白质丰度变化有显著差异。采用MALDI-TOF-TOF/MS鉴定所获得的差异蛋白,从YL6、F172中分别鉴定出18、14个蛋白的氨基酸序列,对所鉴定的蛋白质根据功能分为8类。YL6中参与自由基清除的2个,参与光合作用的6个,参与细胞生长和分裂的1个,参与基础代谢的6个,参与防卫反应的2个,未知功能蛋白1个。F172中参与自由基清除的1个,参与光合作用的2个,参与细胞生长和分裂的2个,参与基础代谢的4个,参与信号转导的2个,参与蛋白加工的1个,未知功能蛋白2个,其中22 k D干旱诱导蛋白的丰度明显提高,而在YL6中则检测不到此蛋白。这说明在干旱胁迫下抗旱性不同的甘蔗品种在蛋白质组成上有很大差异,推测这是不同甘蔗品种间抗旱性差异的重要分子基础。

Analysis of Differential Proteome in Relation to Drought Resistance in Sugarcane

Drought stress is a major restraint in sugarcane production in China. Proteomic study in relation to drought stress provides valuable information in drought resistant breeding of sugarcane. In this study, the drought-resistant sugarcane variety, F172, and the drought-sensitive variety, YL6, were used in a pot experiment for differential proteome analysis. Seedlings of both varieties were exposed to severe drought stress for seven days and the leaf proteins were separated and analyzed using 2-DE technique and PDQuest software. From the protein profiles of F172 and YL6, 28 and 20 differential protein spots were detected between normal-irrigation and drought-stress treatments, respectively, including up- and down-regulated proteins and new protein spots. The differential proteins varied across the two varieties. Using MALDI-TOF-TOF/MS, 18 and 14 amino acid sequences were identified from YL6 and F172, respectively, and they were in eight function categories. In YL6, the 18 proteins consist of two participating in oxygen radical scavenging, six participating in photosynthesis, one participating in cell growth and division, six participating in basic metabolisms, two participating in protective response, and one unknown in function. In F172, the 14 proteins consist of one participating in oxygen radical scavenging, two participating in photosynthesis, two participating in cell growth and division, four participating in basic metabolisms, two participating in information transfer, one participating in protein processing, and one unknown in function. A drought-induced protein of 22 kDa was in high level in F172 but absence in YL6. These results indicate that protein compositions under drought stress are highly different in sugarcane varieties with different drought resistance and the differential proteins might give a hint to drought-resistant mechanism.