拟南芥MPK3、MPK4、MPK6在酵母hog1Δ中的渗透调节作用

Osmoregulation of MPK3,MPK4 and MPK6 from Arabidopsis thaliana in Yeast hog1Δ Mutant

【目的】研究拟南芥MAPK信号转导途径的关键基因MPK3、MPK4、MPK6的功能,明确其在渗透调节中的作用。【方法】构建拟南芥MPK3、MPK4、MPK6的酿酒酵母表达载体,遗传转化酿酒酵母渗透调节功能丧失的hog1?突变体,筛选得到阳性转化子,并分析其在渗透胁迫下的表型特征。【结果】扩增得到了拟南芥MPK3、MPK4、MPK6的全长cDNA序列,构建了上述3个基因的表达载体,并筛选得到了3个基因的阳性转化子。在1 mol.L-1 KCl、0.3 mol.L-1 LiCl、1 mol.L-1 NaCl、1 mol.L-1 Sorbitol的盐胁迫处理下,阳性转化子生长状态良好,与野生型的表型基本一致,均恢复了hog1?对盐胁迫的抗性。在盐胁迫处理下,hog1?细胞形态异常且体内甘油含量较野生型低,而转化子的形态和体内甘油含量均恢复到正常的表型。【结论】MPK3、MPK4、MPK6均能够使酿酒酵母渗透调节功能丧失突变体hog1?恢复对盐胁迫的抗性,具有渗透调节的功能。

【Objective】The objective of this research is to study MPK3,MPK4 and MPK6 which are the key genes of MAPK signal transduction pathway,and to identify these MAPKs in osmoregulation of Arabidopsis thaliana.【Method】The yeast expression vectors pVT102U-MPK3/MPK4/MPK6 were constructed,and were transformed into the yeast HOG1 null mutant（hog1？）,and the positive transformants were characterized by complementation.【Result】 The full length cDNA of MPK3,MPK4 and MPK6 gene was amplified,and then transformed into hog1？ of Sacharomyces cerevisiae through yeast expression vector.Under salt stress with 1 mol？L-1 KCl,0.3 mol？L-1 LiCl,1 mol？L-1 NaCl and 1 mol？L-1 sorbitol,the growth of transformants was very well which was almost in accordance with wild type strains,and these genes rescued hog1？ to phenotype of wild type which is insensitive to salt stress.Under salt stress,the cell morphology of hog1？ was aberrant and its intracellular glycerol concentration was lower than WT,but the morphology and glycerol content of transformants was a normal phenotype.【Conclusion】With function of osmoregulation,MPK3,MPK4 and MPK6 could rescue hog1？ from loss of resistance to salt.