Bt转基因棉氮代谢生理变化的研究

Study on the Physiological Change of Nitrogen Metabolism in Bt Transgenic Cotton

在田间条件下,对Bt杂交棉科棉1号和常规棉新洋822及其亲本的氮代谢生理情况进行研究。结果表明:Bt棉的氮代谢较强,以盛铃期最为明显,表现为叶片全氮含量明显升高,科棉1号和新洋822在盛铃期分别比亲本增加36.01%和18.96%,而棉铃全氮含量显著下降。氨基酸和可溶性蛋白质含量显著提高,盛铃期科棉1号和新洋822叶片游离氨基酸分别增加10.86%和9.44%,可溶性蛋白分别增加9.82%和8.31%。叶片硝酸还原酶(NR)、丙酮酸转氨酶(GPT)活性增强,科棉1号和新洋822盛蕾期NR活性比其亲本分别高28.37%和12.83%;GPT活性在盛蕾期和盛铃期比亲本分别增加10.51%、4.38%和39.04%、29.05%,蛋白酶活性则明显下降。因此对于Bt基因导入的棉花品种在推广应用过程中应及时调控棉株氮代谢生理强度,以保持营养生长和生殖生长的平衡。

Two Bt transgenic cotton cultivars, one is hybrid for Kemian No.1, another is conventional for Xingyang 822, were used to study the change of nitrogen metabolism comparing their parents under field condition during the 2001, 2002 cotton growing seasons. The results showed that the intensity of nitrogen metabolism was higher for Bt cotton than that for their parents, especially in peak boll period. In comparison to their parents, the total nitrogen content in the leaf increased, the apparent increase was 36.01% in boll period for Kemian No1, 18.96% for Xingyang 822. The total nitrogen in boll decreased significantly. The NP and GPT activity was higher, the NP activity increased 28.37% for Kemian No1 and 12.83% for Xingyang 822 during peak square period; the GPT activity increased 10.51% and 4.38% during peak square period and peak boll stage for Kemian No.1, 39.04% and 29.05% for Xingyang 822. The content of free amino acid and soluble protein increased significantly, during boll period, the free amino acid increased 10.86% for Kemian No.1, 9.44% for Xingyang 822, the soluble protein rose 9.82% for Kemian No.1, 8.31% for Xingyang 822. the protease activity declined significantly. These results indicated that the mediation of nitrogen metabolism was necessary for keeping the balance between carbon and nitrogen metabolism as the Bt cotton extension in field production.