Thermal stress induces differential degradation of Rubisco in heat-sensitive and heat-tolerant rice
Thermal stress induces differential degradation of Rubisco in heat-sensitive and heat-tolerant rice
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DOI：
10.1034/j.1399-3054.1999.105114.x
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发表时间：
1999-01-01
影响因子：
6.4
通讯作者：
Ghosh, B
中科院分区：
文献类型：
--
作者：
Bose, A;Tiwari, BS;Ghosh, B
采用[S-35]-蛋氨酸脉冲追踪法、大亚基（LSU）转录水平和蛋白酶活性研究了两个水稻品种在气温升高条件下1，5-二磷酸核酮糖羧化酶/加氧酶（Rubisco，EC.4.1.1.39）的降解以及品种差异对酶损伤程度的影响。N22和IR 8分别被鉴定为耐热和热敏品种.在两个品种中观察到不同的反应，与N 22表现出更大的Rubisco蛋白的热稳定性高达45摄氏度，而IR 8是热不稳定的。通过北方印迹杂交研究，LSU的转录水平在N22中也显示出热稳定性，而在IR 8中它是温度敏感的。通过[S-35]-蛋氨酸和北方印迹分析表明，在两个品种中表现出相同的趋势，并与蛋白质周转相关。结果表明，两个水稻品种间存在遗传差异，耐热品种对Rubisco热降解具有保护机制。
Degradation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC.4.1.1.39), due to elevation in atmospheric temperature, and extent of enzyme damage, due to varietal differences, were studied by [S-35]-methionine pulse-chase, transcript level of the large subunit (LSU), and protease activity in two rice cultivars. The cultivars N 22 and IR 8 are certified as thermotolerant and thermosensitive, respectively. Differential responses were observed in both cultivars, with the N 22 showing greater thermostability of the Rubisco protein up to 45 degrees C, whereas IR 8 was thermolabile. Elevation of the temperature to 50 degrees C favored the degradation of the protein in both cultivars, The transcript level of the LSU, as studied by Northern blot hybridization, also showed thermostability in N 22, whereas it was thermosensitive in IR 8, Protease activity, as measured by Western blot analysis using purified Rubisco, revealed the same trend in both cultivars and was correlated with protein turnover by [S-35]-methionine and Northern blot analysis. The results indicate that genetic differences exist in two rice cultivars and that the heat-tolerant cultivar has a protective mechanism against thermal degradation of Rubisco.