盐胁迫对苗期番茄蔗糖代谢的影响

研究了不同浓度盐胁迫下番茄苗期蔗糖代谢相关酶（转化酶、蔗糖合成酶、蔗糖磷酸合成酶）的活性变化与糖积累的关系。结果表明：盐胁迫在一定程度上可以提高番茄幼苗体内的果糖和葡萄糖含量，降低蔗糖的含量。短期盐胁迫可以提高番茄幼苗体内转化酶的活性，使相应的可溶性酸性转化酶mRNA水平提高，处理后期转化酶活性及可溶性酸性转化酶mRNA水平下降；蔗糖合成酶和蔗糖磷酸合成酶的活性降低，但与对照之间的差异不显著；表明盐胁迫主要通过调节转化酶表达与活性变化来影响番茄苗期的蔗糖代谢水平。

Effect of Salt Stress on Sucrose Metabolism of Tomato Seedlings

The correlation between the related enzymes activities of sucrose metabolism ( invertase, sucrose synthase, sucrose phosphate synthase) and sugar composition (sucrose, glucose, fructose) and content of tomato (Lycopersicon esculentu) were determined and analyzed under different concentration of salt stress. The results indicated that fructose and glucose content were increased under salt stress to a certain degree in tomato seedlings, but sucrose content was reduced. Invertase activities were enhanced in a short period of time, and also elevated expression of soluble acid invertase mRNA in tomato seedlings under salt stress, moreover. Sucrose synthase and sucrose phosphate synthase were reduced under salt stress, but compared no significant difference with control. It was suggested that the level of tomato seedlings sucrose metabolism were mainly modulated by gene expression and activities of acid invertase under salt stress.