Zhao Caifeng, Wang Jingqiang, Cao Mengliang, Zhao Kang, Shao Jianmin, Lei Tingting, Yin Jianning, Hill Gradford G, Xu Ningzhi, Liu Siqi
Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China.
Proteomics. 2005 Mar;5(4):961-72. doi: 10.1002/pmic.200401131.
Of the numerous factors affecting rice yield, how solar radiation is transformed into biomass through rice leaves is the most important. We have analyzed proteomic changes in rice leaves collected from six different developing stages (vegetative to ripening). We studied protein expression profiles of rice leaves by running two-dimensional gel electrophoresis. Differential protein expression among the six phases were analyzed by image analysis, which allowed the identification of 49 significantly different gel spots. The spots were further verified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, in which 89.8% of them were confirmed to be rice proteins. Finally, we confirmed some of the interesting rice proteins by immunoblotting. Three major conclusions can be drawn from these experimental results. (i) Protein expression in rice leaves, at least for high or middle abundance proteins, is attenuated during growth (especially some chloroplast proteins). However, the change is slow and the expression profiles are relatively stable during rice development. (ii) Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), a major protein in rice leaves, is expressed at constant levels at different growth stages. Interestingly, a high ratio of degradation of the RuBisCO large subunit was found in all samples. This was confirmed by two approaches, mass spectrometry and immunoblotting. The degraded fragments are similar to other digested products of RuBisCO mediated by free radials. (iii) The expression of antioxidant proteins such as superoxide dismutase and peroxidase decline at the early ripening stage.
在影响水稻产量的众多因素中，太阳辐射如何通过水稻叶片转化为生物量是最为重要的。我们分析了从六个不同发育阶段（营养生长至成熟）采集的水稻叶片中的蛋白质组变化。我们通过二维凝胶电泳研究了水稻叶片的蛋白质表达谱。通过图像分析对六个阶段之间的差异蛋白质表达进行了分析，从而鉴定出49个显著不同的凝胶斑点。这些斑点通过基质辅助激光解吸/电离飞行时间质谱进一步验证，其中89.8%被确认为水稻蛋白质。最后，我们通过免疫印迹法确认了一些有趣的水稻蛋白质。从这些实验结果可以得出三个主要结论。（i）水稻叶片中的蛋白质表达，至少对于高丰度或中等丰度的蛋白质而言，在生长过程中会减弱（尤其是一些叶绿体蛋白质）。然而，这种变化较为缓慢，且在水稻发育过程中表达谱相对稳定。（ii）核酮糖-1,5-二磷酸羧化酶/加氧酶（RuBisCO）是水稻叶片中的一种主要蛋白质，在不同生长阶段表达水平恒定。有趣的是，在所有样品中都发现RuBisCO大亚基的降解比例很高。这通过质谱和免疫印迹两种方法得到了证实。降解片段与由自由基介导的RuBisCO的其他消化产物相似。（iii）超氧化物歧化酶和过氧化物酶等抗氧化蛋白的表达在早熟阶段下降。
