Abstract:

Development of an appropriate two-dimensional gel electrophoresis (2-DE) technique for samples from various sources is important for proteomics study. Here, we report a modified 2-DE protocol suitable for rice microsomal proteins by using differential centrifugation in sample preparation, optimizing length and pH range of immobilized pH gradient (IPG) strips, and modifying the electrophoresis program. We used the 2-DE technique to detect the change of rice microsomal proteins expression induced by bentazon in Norin 8 (N8) as well as its bentazon sensitive lethal mutant Norin 8m (N8m). Results showed that 15 differentially expressed protein spots were found after bentazon treatment between or within the two lines. The proteins in these spots were classified into three types. TypeⅠ proteins showed differential expression between the two lines while typeⅡ proteins differed between the treated and untreated samples, and typeⅢ proteins were only induced in N8 after the treatment. TypeⅠ proteins arise from rice DNA damage by γ-ray radiation, based on the fact that N8m is a new strain from N8 mutated by γ-ray. Our previous study indicated that N8 and N8m showed no significant difference in the alteration of photosynthesis in the early stage after bentazon treatment, which induced accumulation of oxidative stress. It can be confirmed that typeⅡ proteins are related to the reactive oxygen scavenging system or systemic acquired resistance. The analysis of bentazon content change in 24 h indicated that N8 could metabolize the absorbed bentazon thoroughly while residual bentazon was present in the treated leaves of N8m. Therefore, we predict the typeⅢ proteins to be related to bentazon metabolism.

Key words: Rice, Microsome, Two-dimensional gel electrophoresis, Bentazon, Tolerance