一氧化氮参与调节盐胁迫诱导的玉米幼苗脱落酸积累

以三叶一心期的玉米幼苗为实验材料，研究了盐胁迫下玉米幼苗根尖和叶片中一氧化氮（NO）和脱落酸（ABA）积累之间的关系。结果表明，盐胁迫下玉米幼苗NO和ABA的含量均增加，用NO供体硝普钠（Sodium nitroprusside，SNP）处理时，ABA含量亦增加，且累积的时间较盐胁迫下早。用NO合成的抑制剂L-NAME （Nω-nitro-L-arginine methyl ester hydrochloride）和NaN，处理时，可减弱盐胁迫诱导的ABA含量的增加，用NO清除剂cPTIO处理时，这种盐胁迫诱导的ABA增加减少。推测盐胁迫下产生的NO参与调节ABA的积累及逆境下植物的防御反应。

Involvement of Nitric Oxide in Regulation of Salt Stress-induced ABA Accumulation in Maize Seedling

Possible regulation of salt stress-in-duced ABA accumulation by nitric oxide(NO)in maize seedling was investigated.Both NO and ABA contents of maize leaves and root tips were increased in response to salt stress(Figs.1,2).Simi-lar to the effects of salt stress,ABA contents of maize leaves and root tips were increased after the treatment of maize leaves with sodium nitroprus-side(SNP,a nitric oxide donor)alone(Fig.3).Compared to the salt stress-induced ABA accumulation,this SNP-induced ABA increase was much faster,suggesting that NO may be an inter-mediate signal from salt stress to ABA accumulation.When NO production inhibitors L-NAME and NaN3 treatments were applied,saltstress-induced ABA accumulation was lowered(Fig.4).Treatment with NO scavenger cPTIO also inhibited the salt stress-induced ABA increase(Fig.5).From these results it is deduced that NO is in-volved in regulation of ABA accumulation under salt stress.