Identification of differentially expressed proteins of a new rice mutant with albino green-revertible trait in the seedling stage

Abstract

Chlorophyll-deficient mutants have been employed to study the mechanism of chlorophyll and chloroplast biogenesis in plants. We found a new chlorophyll-deficient mutant rice line (W02S) whose leaves, unlike those of its isogenic line (Peiai64S), became etiolated at the two-leaf stage and turned green at the three-leaf stage. 2-D gel electrophoresis was performed, and proteins that were differentially expressed between W02S and Peiai64S were selected for MALDI-TOF MS analysis. A total of 44 highly differentially expressed proteins were collected from the two-leaf stage of W02S. These 44 proteins can be classified into 10 categories, 15 were novel and unknown functional proteins, 6 proteins participated in the EMP-TCA-ETC pathway, and 4 proteins were involved in the in signal transduction. Four representative protein spots were selected for real-time quantitative PCR analysis. The mRNA levels of three genes encoding an enolase, a chloroplast 29 kDa ribonucleoprotein and a proteasome alpha subunit were significantly increased in the samples from the two-leaf stage of W02S, indicating that a substantial proportion of protein changes is the consequence of altered mRNA levels during the seedling stages of the mutant rice. These findings provide new insights into the mechanisms for chlorophyll-deficient mutant rice and other plants as well.Key words: Oryza sativa L., 2-D gel , real time PCR, chlorophyll-deficient mutant