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作者	单位
杜红阳，李青芝，杨青华，刘怀攀	（1.周口师范学院生命科学与农学学院，河南周口 460001； 2.河南农业大学农学院，河南郑州 450003）

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中文摘要:

为了探讨多胺提高小麦抗旱性的机理，以两个抗旱性不同的小麦品种（豫麦48，抗旱性较弱；洛麦22，抗旱性较强）为材料，研究了亚精胺对短期渗透胁迫下小麦幼苗叶片渗透调节物质含量以及脯氨酸代谢的调控效应。结果表明，渗透胁迫下，两个小麦品种幼苗叶片中脯氨酸、葡萄糖和蔗糖含量增加，且抗旱性较强的洛麦22增加幅度显著大于抗旱性较弱的豫麦48；脯氨酸代谢关键酶Δ 吡咯啉 5 羧酸合成酶（P5CS）和Δ 吡咯啉 5 羧酸还原酶（P5CR）活性增强，且洛麦22的P5CS活性增强幅度大于P5CR。但渗透胁迫处理对两个品种鸟氨酸转氨酶（OAT）活性影响不大。外源亚精胺处理则进一步提高了渗透胁迫下脯氨酸、葡萄糖、蔗糖含量以及P5CS和P5CR活性，且对抗旱性较弱的豫麦48效应较明显，但对两个品种的OAT活性基本没什么影响。这些结果表明，外源亚精胺处理能通过提高脯氨酸合成代谢谷氨酸途径的关键酶P5CS和P5CR的活性促进脯氨酸和可溶性糖的积累，从而提高小麦幼苗的保水性，增强其抗旱性，对抗旱性较弱的小麦品种的效果更加明显。

英文摘要:

In order to elucidate the mechanism that polyamines improve the drought resistance of wheat seedling, two wheat (Triticum aestivum L.) cultivars Yumai 48 (drought sensitive) and Luomai 22 (drought tolerant) were used as experiment materials, the effects of spermidine(Spd) on the contents of osmoregulation substance and the activity of proline metabolic enzyme in wheat seedling were studied under short time osmotic stress. Results showed that under osmotic stress, the contents of proline, glucose and saccharose increased in the two cultivars, and those of drought tolerant cultivar Luomai 22 increased more significantly than that of drought sensitive cultivar Yumai 48; the activities of pyrroline 5 carboxylate synthase (P5CS) and pyrroline 5 carboxylated reductase (P5CR) also improved, and the P5CS activity of Luomai 22 increased more significantly than P5CS activity. However, the ornithine aminotransferase (OAT) activity was slightly affected by osmotic stress in the two cultivars. The treatment with exogenous spermidine further improved the contents of proline, glucose, saccharose and the activities of P5CS and P5CR, and the effect on Yumai 48 was more obvious than on Luomai 22. Nevertheless, there was little effects on OAT activity. The results suggested exogenous spermidine (Spd) promoted proline accumulation via improving the activity of P5CS and P5CR, and increased soluble sugar contents, which enhanced water retaining capacity and drought resistance of wheat seedling, especially there were more obvious effects on the drought sensitive cultivar.

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