中文摘要：

为了探索H2S对干旱胁迫下萌发水稻种子中淀粉酶活性的影响,本研究以‘粤优589’水稻（Oryza sativa L.）杂交种子为实验材料,以20%PEG模拟干旱,0.75 mmol/L硫氢化钠（NaHS）作为外源H2S供体,采用DNS比色法、碘染等方法探究水稻种子萌发过程中淀粉酶活性变化、种子吸胀速率、胚乳乳化等现象。结果表明：在干旱胁迫条件下,外源H2S供体NaHS处理使水稻种子吸水速度加快1.5 h;在胚乳乳化过程中,NaHS处理的淀粉分泌斑块较PEG处理大,碘染后液化现象明显优于PEG处理;与PEG相比,NaHS处理的淀粉酶活性呈现显著增强趋势,且第4天增高幅度最大,总淀粉酶活性提高67.14%,α-淀粉酶活性提高35.31%,β-淀粉酶活性提高71.79%,且在水稻种子萌发初期,β-淀粉酶的贡献大于α-淀粉酶;H2S的抑制剂羟胺（NH2OH）则逆转了外源H2S供体NaHS对水稻种子萌发的作用效应。证实外源H2S有效地缓解干旱胁迫对水稻种子萌发的抑制作用,提高淀粉酶活性,加快种子吸胀速率、胚乳乳化速度,显著地促进水稻种子的萌发。

英文摘要：

To explore the effect of H2S on the amylase activity in germinating rice seeds under drought stress,‘Yueyou 589＇（Oryza sativa L.） hybrid rice（Oryza sativa L.） seeds were used as the experimental materials with20% PEG imitating drought and sodium hydrosulfide（NaHS） as the donor of exogenous H2S in this study. The change of amylase activity, the imbibitions rate of seeds and the emulsification of endosperm were investigated by using the methods including DNS Colorimetry and I-KI staining. The results showed that, NaHS treatment could decrease absorption time by 1.5 hours under drought stress conditions; The secretion of starch plaque and iodine staining for liquefaction of NaHS treatment was significantly higher than that of PEG in the emulsification process of endosperm; Amylase activity of NaHS showed an obvious growth than that of PEG, where the biggest increase of the total amylase（67.14%）, alpha amylase（35.31%） and beta amylase activity（71.79%） at the fourth day; The contribution of beta amylase was greater than alpha amylase during the primary germination of rice seed. The H2S inhibitors hydroxylamine（NH2OH） reversed the effect of NaHS on the rice seeds germinating. All the results confirmed that exogenous H2S could effectively alleviate the inhibition by drought stress in rice seeds germination,increase amylase activity, accelerate the rate of seed imbibitions and endosperm emulsification, and significantly promote the germination of rice seeds.