低分子有机酸和镉对小麦幼苗生化作用及生长的影响

本研究采用营养液培养的方法，以小麦为实验材料(辽春9号，Triticum aestivum L.)，研究了重金属镉和低分子有机酸(柠檬酸和苹果酸)对小麦生化作用及生长的影响．在镉浓度为0.5mmol I^-1时，小麦呈现叶片失绿、枯萎的症状，生长受到严重影响．与只施加镉的处理相比较，柠檬酸和苹果酸均能一定程度上提高小麦的鲜重、干重及叶片中叶绿素的含量，降低小麦干／鲜重比、叶片内自由脯氨酸和丙二醛的含量．在营养液培养条件下，有机酸表现出能阻止镉通过根系进入小麦体内，降低小麦中的镉浓度．对小麦的形态和体内一些生物化学指标的研究表明，有机酸能明显减轻镉对小麦的毒性．

Interactive Effects of Low Molecular Weight Organic Acids and Cadmium on Some Biochemical Compounds and Growth in Wheat Seedlings

In this study, the interaction between low molecular weight organic acids (LMWOA) and cadmium stress was investigated in wheat seedlings ( Triticum aestivum L. cv. Liaochun-9) with a method of nutrient solution culture. Effects of different concentration of citric and malic acids (0,0.5 1.0mgL-1) under the condition of cadmium stress (0.5 mM L-1) to the wheat seedlings were detected by measuring changes in the plant biomass, total chlorophyll, free proline, malondialdehyde (MDA) and cadmium concentration. The Results showed that citric and malic acids appeared to inhibit cadmium transporting into wheat seedlings through root, and hence decreased wheat cadmium concentration to a relative extent. Total chlorophyll in wheat seedlings treated with organic acids was higher than that only treated with cadmium, whereas proline, malondialdehyde (MDA) in wheat seedlings with organic acids applied represented the contrary trend as compared that only with cadmium applied. These data indicated that low molecular weight organic acids decreased cadmium toxicity to plant.