NaCl 胁迫下小麦突变体和野生型叶片中一些有机溶质累积和基因表达差异

Differences in the Accumulation of Some Organic Solutes and Gene Expression in Leaves Between the Salt tolerant Mutant and the Wild Type of Wheat Under NaCl Stress

盐胁迫下突变体和野生型叶片中的脯氨酸累积量均有显著的增加，野生型的增加幅度不及突变体。至９６ ｈ ，两者含量均下降，但突变体的脯氨酸含量仍高于野生型。１００ｍ ｍｏｌ／Ｌ的ＮａＣｌ 胁迫７２ ｈ ，突变体叶片中可溶性糖的含量有显著的增加，增加量随盐浓度增加而降低。至９６ ｈ，各个盐浓度处理的突变体可溶性糖的含量基本恢复到其对照的水平；除１００ ｍｍｏｌ／Ｌ 盐胁迫处理组外，野生型叶片中可溶性糖含量均大幅度下降。盐胁迫下突变体和野生型叶片细胞可溶性蛋白组分有明显的差异。ｍＲＮＡ 差异显示结果表明，突变体有６ 个差异性的ｃＤＮＡ

Proline content in leaves of the mutant increased more significantly than that of the wild type when exposed to NaCl stress (Fig.1). The content of proline increased for 72 h and then decreased in both types, but was higher in the mutant than in the wild type (Fig.2).When exposed to NaCl stress of 200 or 300 mmol/L for 96 h, the content of soluble sugars in leaves of the mutant maintained a higher level than that of the group without NaCl treatment, but that in the wild type became much lower than that of its control group (Fig.3). These results indicated that the contents of proline and soluble sugars in leaves of the mutant were higher than those of the wild type, which played the role of osmotic adjustment.The protein compositions of leaf cells of the mutant and the wild type were different. Under salt stress, the 88 kD peptide disappeared and an increase in 56 kD peptide was induced in leaf cells of the mutant by salt. In contrast, the quantity of the 88 kD peptide remained stable while the 56 kD peptide became less or even disappeared with the increase in salt concentration (Fig.4). By using DD PCR techniques, it was found that the mutant had six cDNA fragments specially expressed more than the wild type under salt stress (Fig.5).