一氧化氮在萘乙酸诱导不定根形成过程中的作用研究

The role of nitric oxide in 1-naphthylacetic acid-induced adventitious roots formation

研究了新型信号分子一氧化氮(NO)在萘乙酸(NAA)诱导绿豆下胚轴插条不定根形成过程中的作用.结果表明,与对照相比,一氧化氮供体硝普钠(SNP)和NAA都显著诱导插条不定根形成,根数、鲜重和干重都显著高于对照.SNP和NAA复合处理的生根效果明显好于两者单独处理.不同浓度NO清除剂羧基-2-苯-4,4,5,5-四甲基咪唑-1-氧-3-氧化物(c-PTIO)能够有效抑制NAA诱导不定根形成,其最适浓度为200μmol/L.此外,一氧化氮合酶(NOS)抑制剂L-硝基精氨酸甲酯(L-NAME)也能够部分抑制NAA诱导的生根效应,最适浓度为30mmol/L.内源NO检测结果表明NAA处理后NO水平明显提高,c-PTIO和L-NAME则抑制此效应.结果表明,NO在NAA诱导绿豆下胚轴插条不定根形成过程中起着至关重要的作用,NOS参与此过程中NO的产生.

The role of nitric oxide（NO） in naphthaleneacetic acid（NAA）-induced adventitious roots formation in mung bean（Phaseolus radiatus L.） hypocotyl cuttings was studied.The results showed that,compared with the control,both NO donor sodium nitroprusside（SNP） and NAA significantly raised number,fresh and dry weight of adventitious roots.The treatment with complex of NAA and SNP resulted in significant increase in adventitious roots number compared with the treatment using SNP or NAA alone.Carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline（c-PTIO）,a NO specific scavenger,effectively inhibited NAA-induced adventitious root formation,and the optimal concentration was 200 μmol/L.Furthermore,inhibitor of nitric oxide synthase（NOS）,N＇-nitro-L-arginine methyl ester（L-NAME） partly inhibited the effect from NAA,the optimal concentration was 30mmol/L.Detection of endogenous NO showed that the level of NO was obviously promoted by NAA,however,innibitd by c-PTIO and L-NAME.All results mentioned above indicated that NO plays a key role in NAA-induced adventitious roots formation,and NOS is involved in the generation of NO in this process.