水稻叶片对镉胁迫响应的蛋白质差异表达

Differential expression of proteins in Oryza sativa leaves in response to cadmium stress

为揭示水稻镉抗性的分子机理,以抗镉水稻品种PI312777和镉敏感水稻品种IR24为材料,在镉离子浓度为0(对照)、50和100μmol·L-1条件下水培处理7 d,应用蛋白质组学方法分析了2种水稻叶片对镉胁迫响应的蛋白质差异表达.结果表明:镉胁迫下水稻PI312777叶片中共检测到差异表达蛋白质点31个,通过MALDI-TOF/MS分析,鉴定了其中的24个蛋白质(包括20个不同蛋白质,4个重复检出蛋白质);IR24叶片中共检测到差异表达蛋白质点19个,其中15个蛋白质得到鉴定.PI312777叶片鉴定出的20个蛋白质覆盖了IR24叶片鉴定的15个蛋白质,前者有4个与光合作用相关,11个与细胞防御代谢相关,3个与其他代谢相关,2个为功能未知蛋白.与对照相比,不同浓度镉胁迫下,抗镉水稻PI312777叶片中热激蛋白、谷胱甘肽还原酶、蛋白酶体α亚基6型、果糖1,6-二磷酸醛缩酶、硫氧还蛋白和DNA重组修复蛋白均上调表达;镉敏感水稻IR24叶片中热激蛋白、谷胱甘肽还原酶、蛋白酶体α亚基6型的表达无显著差异,果糖1,6-二磷酸醛缩酶和硫氧还蛋白则下调表达.此外,DNA重组修复蛋白仅在镉胁迫的PI312777叶片中表达.水稻PI312777比IR24具有更强的镉抗性与这些差异表达的蛋白质密切相关.

In order to explore the cadmium（Cd）-tolerance mechanism of rice（Oryza sativa）,a hydroponic experiment with Cd-tolerant rice cultivar PI312777 and Cd-sensitive rice cultivar IR24 was conducted.The cultivars were treated with 0（control）,50,and 100 μmol·L-1 of Cd2＋ for 7 days,and the differential expression of proteins in their leaves were analyzed by two-dimensional electrophoresis and MALDI-TOF/MS approach.Under Cd stress,31 protein spots in PI312777 leaves and 19 protein spots in IR24 leaves had significantly different expression,compared with the control.In PI312777 leaves,the 24 of 31 proteins had 4 proteins related to photosynthesis,11 proteins related to cell metabolism and defense,3 proteins related to other metabolism pathway,and 2 proteins were unknown proteins;in IR24 leaves,the 15 of 19 proteins were identified.Under Cd-stress,the heat shock protein,glutathione-diulfide reductase,poteasome subunit alpha type-6,1,6-bisphosphate aldolase,thioredoxin,and DNA repair-recombination protein in PI312777 leaves were up-regulated expressed,while these proteins in IR24 were not significantly changed except the down-regulation of 1,6-bisphosphate aldolase and thioredoxin.The higher Cd-tolerance of PI312777 could have close relations with the differentially expressed proteins.