Abstract: High salinity stress adversely affects plant growth and development. Compared with cultivated soybean, the wild soybean has more salt-tolerant genes in genome because of its broad distribution, the large genetic diversity and the wide adaptation to different environments. The comparative analysis of physiological and biochemical characters of the salt resistant wild soybean ST-335 and salt sensitive one SS-736 were carried out in this study. The effects of some genes mediating Na+ and K+ homeostasis on soybean salt tolerance were analyzed by overexpressing genes in soybean hair roots. The results showed that the content of soluble sugar and the activities of SOD, POD,CAT were higher in ST-335, Na+/K+ ratio was lower in ST-335. The relative expressions of KOR，NHX and NSCC were lower and the relative expressions of SKOR and SOS1 were higher in ST-335 than that in SS-736. The overexpression of SOS1 and SKOR in soybean hair root enhanced the salt tolerance in soybean composite plants, while overexpression of NSCC decreased the salt tolerance in soybean. These results suggested that the oxidative stress tolerance and ion balance in ST-335 were better than that in SS-735. The results of this study provided theoretical basis for deciphering the salt tolerance mechanism and selecting salt tolerant germplasm of wild soybean.

Key words: wild soybean, NaCl stress, physi-biochemical traits, Na+/ K+

摘要： 盐胁迫严重影响植物的生长发育，野生大豆与栽培大豆相比具有更广泛的区域多样性、遗传多样性、环境适应性等优异特征，可能蕴藏着丰富的耐盐基因。以高度耐盐野生大豆资源ST-335和盐敏感资源SS-736为材料，比较了二者在盐胁迫下的生理生化特性；并通过在大豆发状根中过表达离子转运相关基因，分析了这些基因对大豆复合体耐盐性的影响。结果表明：盐胁迫条件下，与盐敏感品种SS-736相比，耐盐品种ST-335的可溶性糖含量高；SOD、POD和CAT活性高；Na+/K+低；且KOR、NHX和NSCC基因表达量低，而SKOR和SOS1基因表达量高。在大豆发状根中过表达SKOR和SOS1基因，提高了大豆复合体的耐盐能力；而过表达NSCC基因，提高了大豆复合体对高盐胁迫的敏感性。说明ST-335与SS-736相比具有较高的抗氧化能力并能较好的维持植物体内Na+、K+的平衡，综合解析了不同抗性野生大豆资源应对高盐胁迫的机理，为野生大豆耐盐资源筛选及耐盐机理解析提供了理论基础。

关键词: 野生大豆, NaCl胁迫, 生理生化性状, Na+ / K+