Abstract
To identify the mechanism of GA signal transduction in rice basal part, a proteomic approach was used. Growth of rice seedlings were stimulated when treated with 5 μM GA3 for 24 h to extract proteins. The difference in protein expression pattern between control and treatment was displayed by 2D-DIGE. The expression of five proteins were increased and one protein was decreased. Identification of these proteins by mass spectrometry analysed that they were elongation factor 1 beta, 21 kDa polypeptide, abscisic acid, stress and ripening 5 (ASR5) and fructose-diphosphate aldolase. After quantification of the relative expression levels of these proteins, ASR5 was significantly up-regulated by GA3. However, ASR5 did not change at mRNA level. Polyclonal antibody was raised against ASR5 that was analyzed for subcellular distribution and ABA response. The results indicate that ASR5 is distributed in nucleus and cytoplasm, and responded to both ABA and GA.
