中文摘要：

在不同光信号下，用NO供体（SNP）、ROS清除剂（NAC）、氮合酶（NOS）专一抑制剂（LNNA）处理露白的玉米种子，探讨玉米胚芽鞘生长与NO信号分子间的关系．结果表明：胚芽鞘中存在类NOS活性，并受外源NO和ROS的反馈抑制；尽管外源NO对胚芽鞘的生长有一定的促进作用，但与类NOS活性共同消长的内源NO明显地阻抑胚芽鞘生长．由于黑暗是胚芽鞘适宜的生长环境，所以与黑暗相比较，增强UV-B辐射抑制类NOS活性和内源NO的产生，促进胚芽鞘的生长；正常光周期激活类NOS活性和内源NO的产生，减少胚芽鞘的生长．SNP，NAC和LNNA通过各种不同的机制抑制了NOS活性和内源NO的产生，胚芽鞘的生长就被促进，因此，不同光信号对玉米胚芽鞘生长的影响是通过内源NO信号分子实现的．

英文摘要：

The germinated first seeds were treated with a solution containing SNP, NAC and LNNA under different light signals （such as darkness, photoperiod and enhanced UV-B） to explore the relationship between the growth and NO production in coleoptiles. The results show that NOS-like activities were measured in the cellular microsome and cytosol of the coleoptiles. The exogenous NO might inhibit NOS activities through a negative feedback, but increased the growth of the coleoptiles, whereas the endogenous NO significantly depending on the NOS-like activity inhibited the coleoptile growth. It was well-known that darkness contributes to coleoptile growth ang development. Compared with the darkness signal, the enhanced UV-B inhibited the NOS-like activity to decrease endogenous NO production and promoted the coleoptile growth, while the photoperiod signal sharply contrasted with the enhanced UV-B signal in its function. At the same time, SNP, NAC and LNNA inhibited the NOS-like activity and endogenous NO production and increased the coleoptile growth by various mechanisms. Therefore, the effects of different light signals on the growth of maize coleoptiles were achieved through the production regulation of endogenous NO signal moleculars in the coleoptile.