干旱-高温交叉逆境对小麦叶片蛋白质表达的影响

Effect of Drought and Heat Cross-stress on Protein Expression in Wheat Leaves

采用溶液培养、PEG处理等方法,研究干旱、高温单一逆境以及干旱-高温和高温-干旱交叉逆境下小麦叶片蛋白质含量和组分的变化,同时探究外源Ca2+和Ca2+螯合剂EGTA对交叉逆境下小麦叶片诱导蛋白表达的影响,以探讨Ca2+信使系统及逆境蛋白表达与交叉适应的关系。结果表明,逆境胁迫会引起小麦叶片可溶性蛋白含量的升高,且交叉逆境下可溶性蛋白含量高于单一逆境胁迫;对小麦叶片全蛋白进行SDS-PAGE分析发现,逆境胁迫诱导产生新的蛋白质,其中最为显著的是分子质量为34.3ku和24.0ku的两种新蛋白,且交叉逆境下两种逆境蛋白的百分含量明也显高于单一逆境,特别是干旱-高温交叉胁迫表达量最高。用不同浓度的Ca2+(CaCl2)处理小麦幼苗,均可提高两种逆境蛋白的表达量;而EGTA对两种逆境蛋白的表达产生抑制作用。逆境下可溶性蛋白质(包括新的逆境蛋白)的表达是植物对不同逆境交叉适应的生理基础之一。可见,Ca2+作为胞内信使参与植物的逆境信号传递过程。

Using the methods of solution culture and PEG treatment,the changes of soluble protein content and protein components and the impact of exogenous Ca2＋and EGTA to protein expression were studied under the conditions of drought and heat cross-stress,and to explore the relationship between the Ca2＋ messenger system,stress protein expression and cross-adaptation.The results showed that stress treatment caused the increase of soluble protein content in wheat leaves,and the content of soluble protein was lager under cross-stress treatment than single stress treatment.The SDS-PAGE analysis revealed that two kinds of stress-inducible protein were expressed with the molecular mass of 34.3 ku and 24.0 ku in the leaves of wheat seedlings,the percentage content of the two kinds of stress-inducible protein was more under drought and heat cross-stress condition than under single stress condition.The percentage content of the two kinds of stress-inducible protein increased in wheat seedlings treated with different concentrations of CaCl2,but 1 mmol/L EGTA inhibited the increase of the two kinds of stress-inducible protein.These results indicated that plant resistance to different stress may share the same physical and molecular mechanism,Ca2＋ may participate in plant signaling process to stress.