外源茉莉酸甲酯对小麦幼苗低温耐受性的影响

摘要

The effects of exogenous methyl jasmonate on the physiological and biochemical characteristics and the expression of cold-resistant transcription factor in wheat seedlings under cold acclimation were studied with cuhivar "Aikang 58".The test wheat seedlings were set in two groups:the controlled group was sprayed with double distilled water at low temperature of 4℃,and the treated group was sprayed with 100 μmol/L of methyl jasmonate at 4℃ for a week.The physiological and biochemical results showed that the survival rate of wheat seedling treated with 100 μmol/L of exogenous methyl jasmonate was 91％,significantly increased than that of the controlled group.The SOD、CAT and POD activity of the treated group increased 34％、50％ and 14％ than that of the controlled group,respectively,the content of soluble proteins increased 30％,and intracellular free proline content increased 14％,while MDA content decreased by 5％.There was a significant difference between the treated group and the controlled group.The quantitative real-time PCR showed that 100 μmol/L of exogenous methyl jasmonate significantly increased expression of cold responsive transcription factors TaCBF Ⅳ d-B4,TaCBF Ⅲ d-B19,TaCBF Ⅲ c-D3,and TaCBF Ⅲ d-D19,and the expression of TaCBF Ⅳ d-B4 was the highest.The results indicated that spraying 100 μmol/L exogenous methyl jasmonate enhanced the tolerance of wheat seedlings to low temperature stress.%以矮抗58小麦为材料,探究在冷驯化条件下,外源茉莉酸甲酯对小麦幼苗生理生化特性及抗冻应答因子表达的影响.实验设置两组小麦幼苗,分别用双蒸水和100 μmol/L茉莉酸甲酯溶液喷施4℃低温处理组,低温处理一周.生理生化结果表明,100 u mol/L浓度外源茉莉酸甲酯喷施处理的小麦幼苗存活率达91％,较低温处理组显著升高,细胞内SOD、CAT和POD活性分别较双蒸水喷施对照组活性升高34％、50％和14％,胞内可溶性蛋白含量增加30％,游离脯氨酸含量提高14％,MDA含量相对下降5％,实验组与对照组间具显著性差异;实时荧光定量PCR结果表明,100 μmol/L外源茉莉酸甲酯处理可显著升高冷驯化条件下小麦幼苗中抗寒应答转录因子TaCBFⅣd-B4、TaCBFⅢd-B19、TaCBFⅢc-D3和TaCBFⅢd-D19表达量,其中TaCBFⅣd-B4抗冻应答转录因子表达量最高.结果表明,100 μmol/L外源茉莉酸甲酯的喷施能够增强小麦对低温胁迫的耐受能力.