粳稻95122A和95122B悬浮系建立及抗氧化性分析

Establishment and Antioxidation Ability of Suspension Cell Lines of Japonica Rice 95122A and 95122B

细胞质雄性不育是杂种优势利用的基石,揭示其发生机理将有助于水稻杂种优势的利用。本研究选取已有配组品种的包台型粳稻细胞质雄性不育系95122A及其保持系95122B为材料,基于MS(N6)培养基主成分建立了其状态良好的悬浮细胞系,发现95122B悬浮细胞活力和生长势在各个生长阶段均比95122A的强,两种悬浮细胞从第3~6天进入指数生长期。用不同浓度的H2O2处理第4天活力较强的两种悬浮细胞,对其4种抗氧化酶即过氧化物酶(peroxidase,POD)、过氧化氢酶(catalase,CAT)、超氧化物歧化酶(superoxide dismutase,SOD)和抗坏血酸过氧化物酶(ascorbate peroxidase,APX)活性进行检测时发现,两种悬浮细胞中的4种酶活性均是低H2O2浓度时先略有升高,随后降低,但升高和降低的程度及对应的H2O2浓度依酶的种类不同有所差异,而在相同的情况下,95122B悬浮细胞比95122A悬浮细胞具有较高的抗氧化酶活性,显示95122B具有较95122A强的H2O2抗性。初步确定了适于95122A和95122B悬浮细胞逆境处理的H2O2浓度为10~20 mmol/L。为进一步研究粳稻95122A不育发生的分子遗传机理奠定基础,也为粳型细胞质雄性不育系应用于生产实践提供有力的理论依据。

Cytoplasmic male sterility(CMS) is the basis of utilizing heterosis. Revealing the mechanism of CMS will be helpful for utilizing rice heterosis. In this study, japonica CMS line 95122 A and its maintainer line 95122 B were selected as materials. Their good suspension cell lines were established based on MS(N6) medium. Cell activity and growth potential of 95122 B suspension cell line were higher than those of 95122 A suspension line at all measured growth stages. Suspension cells of 95122 A and 95122 B entered the exponential growth period from the3~6 days, and their four-day suspension cells with higher cell activities were treated with different concentrations of H2O2. Then activities of four antioxidative enzymes SOD(superoxide dismutase), POD(peroxidase), CAT(catalase) and APX(ascorbate peroxidase) in the above treated suspension cells of 95122 A and 95122 B were measured.The results showed that all the enzyme activities increased slightly at low concentrations, and then decreased gradually as the concentrations of H2O2 increased. However, the degree of enzyme activity change(increase or decrease) and its corresponding concentration of H2O2 were different according to different antioxidative enzymes.Under the same conditions, all the four antioxidative enzyme activities in the suspension cells of 95122 B were higher than those in the suspension cells of 95122 A, implying that 95122 B should have higher tolerance under H2O2 stress. A suitable H2O2 concentration of 10~20 mmol/L was suggested for treatment on suspension cells of 95122 A and 95122 B. The results obtained in this study will lay the foundation for further research on the molecular and genetic mechanisms of japonica CMS line 95122 A, and they will also provide a strong theoretical basis for utilizing japonica CMS lines in practice.