锌对不同基因型玉米幼苗碳氮代谢的影响

Effect of Zinc on C,N Metabolism of Different Varied Maize (Zea mays L.) Genotype Seedlings

选用不同耐锌玉米品种‘四单19’(低锌敏感型)和‘牡丹9’(低锌不敏感型),采用营养液水培,研究不同锌浓度对碳酸酐酶(CA)活性、光合特性、可溶性糖含量等的影响。结果表明:玉米对锌具有选择运输的能力,当锌浓度过大对幼苗造成伤害时,根系吸收的锌向地上部运输的比例减少,以减少过量的锌对地上部造成的伤害。锌与CA活性密切相关,而CA活性与净光合速率的变化并非密切相关。低锌和高锌均显著增加了‘四单19’的可溶性糖含量,而‘牡丹9’的可溶性糖含量在缺锌与低锌处理下增加幅度并不明显,但在高锌处理下可溶性糖含量迅速增加。低锌和高锌处理都显著降低了‘四单19’叶片的蛋白质含量,而‘牡丹9’低锌处理下叶片可溶性蛋白含量下降并不明显,但在高锌处理下叶片可溶性蛋白含量大幅度下降。低锌处理下,‘四单19’的蛋白质合成受到抑制,而游离氨基酸大量积累,明显抑制了植株的生长;‘牡丹9’的蛋白质和氨基酸含量变化较小。

Two Zn-tolerant maize cultivars ‘Sidan 19＇ （low zinc sensitive） and ‘Mudan 9＇ （low zinc insensitive） were used as materials to investigate the effects of different Zn contents on CA activity,photosynthetic characteristics,soluble sugar content.The results showed that maize could transport zinc selectively.When zinc concentration was enough to damage seedlings,zinc absorbed by the roots reaching the above-ground decreased to reduce harm them.CA activity and zinc supply were closely related to each other,but CA activity and net photosynthesis,were not closely related to each other.Low zinc and high zinc promoted ＇Sidan 19＇ soluble sugar content notablely;for ‘Mudan 9＇,the soluble sugar content under zinc deficiency and low zinc treatment did not increase significantly,while displayed a rapid increase in high-zinc processing.Under low zinc and high zinc treatment the blades protein content of ‘Sidan 19＇ reduced significantly.The soluble protein content in blades of ‘Mudan 9＇ reduced non-significantly under low zinc processing,and decreased sharply undert high zinc processing.Under low zinc treatment,protein synthesis of ‘Sidan 19＇ was suppressed with a large accumulation of free amino acids,which significantly inhibited the growth of the plants;while the protein and amino acid content of ‘Mudan 9＇ altered a little.