【摘要】 本研究以籼稻（Oryza sativa subsp. indica）‘华占’、‘9311’以及粳稻（O. sativa subsp. japonica）‘越光’、‘中华11’为材料,探讨外源过氧化氢（H₂O₂）对两个亚种种子萌发和幼苗发育的影响。结果表明:质量分数为0.1%的H₂O₂对4个品种种子萌发具有促进作用,对籼稻种子萌发的促进作用尤为显著;水稻幼苗经H₂O₂处理后生长受到明显抑制,叶片中过氧化物酶（POD）和过氧化氢酶（CAT）活性下降,丙二醛（MDA）和内源H₂O₂含量升高,且粳稻中MDA含量变化较籼稻显著,表明H₂O₂对粳稻细胞质膜的氧化损伤更严重; 6个抗氧化酶基因在幼苗叶片中表达下调,过氧化氢酶基因（CATA）在粳稻中下调更明显,谷胱甘肽-S-转移酶基因（GSTU36）在籼稻中下调更明显。以上结果表明,不同品种水稻种子萌发和生长过程中对H₂O₂的敏感性不同,籼稻受外源H₂O₂影响较粳稻明显;在响应环境氧化胁迫时,籼、粳稻幼苗的抗氧化酶基因表达也存在差异性。更多还原

【Abstract】 Four rice（Oryza sativa） varieties（’Huazhan’, ’9311’, ’Koshihikari’ and ’Zhonghua 11’） from two subspecies（indica and japonica） were used to investigate the effect of exogenous hydrogen peroxide（H₂O₂） on seed germination and seedling growth in this study. The seed germination was promoted by H₂O₂ with mass fraction of 0.1%, especially in indica rice. After H₂O₂ treatment, the activities of peroxidase and catalase declined, while the contents of malondialdehyde（MDA） and endogenous H₂O₂ increased in seedling leaves. There was distinct change of MDA content in japonica rice, indicating that more serious oxidative membrane damage was caused than that in indica rice by H₂O₂. In addition, six antioxidant enzyme genes were down-regulated, among which catalase（CATA） and glutathione S-transferase（GSTU36）were more significantly in leaves of japonica and indica subspecies, respectively. These results suggest that different rice varieties have different sensitivity to H₂O₂, and indica rice was more affected by exogenous H₂O₂ than japonica rice. Moreover, the gene expression of antioxidant enzymes was also different in response to environmental oxidative stress in indica and japonica rice seedlings.更多还原