光质对番茄幼苗碳氮代谢及相关酶活性的影响

Effects of Light Quality on Carbon and Nitrogen Metabolism and Enzyme Activities in Tomato Seedlings

采用LED光源,研究了白光(对照)、红光、蓝光、紫光和红蓝(3︰1)组合光对番茄幼苗生长、碳氮代谢及相关酶活性的影响。结果表明:与白光相比,紫光明显抑制幼苗生长,红光抑制幼苗,尤其是其地下部的生长,红蓝组合光下幼苗干物质积累量及壮苗指数最高;在紫光下叶片净光合速率(P_n)、RuBP羧化酶活性、总糖和淀粉含量最低,红蓝组合光下最高;红光和紫光下转化酶的活性较高;红、蓝、紫、红蓝组合光均显著提高蔗糖合成酶(SS)活性,以红蓝组合光更明显,但红、蓝、紫光显著降低蔗糖磷酸合成酶(SPS)活性;红光显著降低了硝酸还原酶(NR)、谷氨酰胺合成酶(GS)和谷氨酸合成酶(GOGAT)活性,蓝、紫、红蓝组合光则显著提高了GS、GOGAT活性以及叶片游离氨基酸和可溶性蛋白含量。总之,红蓝组合光有利于番茄幼苗生长,促进碳同化及总糖和淀粉积累,提高氮代谢相关酶活性及可溶性蛋白和游离氨基酸含量。

The effects of different light quality[（white,red,blue,purple and red-blue（3︰1）] on growth and carbon-nitrogen metabolism in tomato seedlings were investigated by using LED lighting in a growth chamber. The results showed that：Compared with white light,purple light inhibited obviously the growth of seedlings,and red light suppressed the growth of roots,while red-blue light led to highest dry matter weight and seedling index;P_n,RuBP carboxylase activities,and contents of sugar and starch in leaves were lowest in purple light,however,highest in red-blue light. The activities of invertases were higher in both red and purple lighting. Red,blue,purple and red-blue light boosted the activities of sucrose synthase,however,red,blue,and purple light reduced the activities of sucrose phosphate synthase（SPS）. The activities of nitrate reductase（NR）,glutamine synthetase（GS）and glutamate synthetase（GOGAT）were reduced significantly in red light,but activities of GS and GOGAT,and contents of soluble protein and free amino acid were remarkably improved in purple,blue and red-blue light. In conclusion,red-blue light is more suitable for growth of tomato seedlings,not only promoting carbon assimilation and accumulation of total sugar and starch,but also increasing enzyme activities of nitrogen metabolism and contents of soluble protein and free amino acids.