外源CO和NO对水稻种子萌发过程中干旱胁迫损伤的缓解效应

摘要

选用水稻品种'Ⅱ优128'种子为材料,以1.0 μmol·L-1高铁血红素(Hematin,H)和200 μmol·L-1硝普钠(sodium nitroprusside,SNP)分别作为CO和NO供体,采用PEG-6000模拟干旱胁迫,研究外源CO和NO对干旱胁迫下水稻种子萌发和萌发过程中抗氧化能力的影响.结果表明:高铁血红素和硝普钠处理可以显著提高干旱胁迫下水稻种子的发芽率、芽长和根长;同时显著提高种子淀粉酶活性,显著增加其可溶性糖、可溶性蛋白和脯氨酸含量;还不同程度地诱导增强超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性,同时降低质膜相对透性和丙二醛(MDA)含量.研究证实,外源CO和NO可通过调节渗透调节物质含量和保护酶活性来有效缓解干旱胁迫对萌发水稻种子造成的氧化伤害,促进种子萌发生长.%Rice (Oryza sativa L.) variety, 'You Ⅱ 128' seeds were treated with 1.0 μmol · L-1 Hematin (CO donor) and 200 μmol · L-1 SNP (NO donor) to explore the effects of exogenous carbon monoxide (CO) and nitric oxide (NO) on the oxidative damage during rice seed germination under drought stress.The results showed that exogenous CO and NO significantly raised seed germination rate, shoot and root length,activated amylase activity, increased soluble sugar content, soluble protein and proline content.Meanwhile,the results also indicated that CO and NO apparently up-regulated the activities of superoxide dismutase (SOD),catalase (CAT),and peroxidase (POD) ,resulting in the apparent decrease of membrane permeability and MDA content.These results suggested that CO and NO may alleviate drought-induced oxidative damage during seed germination and subsequently induce rice seed germination.