水稻依赖抗坏血酸H_2O_2清除系统在抗铁毒中的作用

Effect of Ascorbate specific H_2O_2 scavenging on Tolerance to Iron Toxicity in Rice

根据营养液培养试验从水稻Ａｚｕｃｅｎａ×ＩＲ６４ 发展的一双单倍体（ＤＨ） 群体中筛选出抗铁毒与敏感品系。在铁毒害处理后，各品系的抗坏血酸过氧化物酶（ＡＰ） 、脱氢抗坏血酸还原酶（ＤＲ） 、谷胱甘肽还原酶（ＧＲ） 的活性均有明显提高；水稻受铁毒后的生物量递减量与ＡＰ、ＤＲ、ＧＲ 活性呈负相关。说明抗坏血酸过氧化物酶Ｈ２Ｏ２ 清除系统在水稻抗铁毒中起着十分重要的作用。

Segregation for tolerance to ferrous iron(Fe 2+ ) was observed in a double haploid(DH) population derived from a cross between a japonica rice cv. Azuacen and an indica rice cv. IR64 in a solution culture experiment conducted. Twenty tolerant and sensitive lines, respectively selected from the population, were used to investigate the role of ascorbate specific H 2O 2 scavenging system in the detoxification of iron in plant(Fig.1). The results indicate that iron stress significantly increases the activities of ascorbate peroxidase (AP), dehydroascorbate reductase (DR) and glutathione reductase(GR)(Table 2). The activities in the tolerant lines are higher than those in the sensitive lines,and significantly negatively correlated with relative decrease in shoot dry weight (RDS)(Table 3). The results suggest that ascorbate specific H 2O 2 scavenging system may play an important role in the detoxification of iron toxicity in rice.