Abstract
We show three proteome analyses using a highly sensitive nanoLC/MS/MS system to identify novel plant proteins involved in signal responses. In the first example, nuclear and nucleic acids-associated proteome analyses of rice proteins resulted in the identification of about 150 proteins that were likely involved in signal responses. The identified proteins included evolutionarily conserved and glucose responsive WD40 proteins and armadillo/pumilio protein. In the second example, proteome analysis of the phloem sap obtained by the insect laser method resulted in the identification of three FT-like proteins that might act as long-distance signaling molecules. In the third example, comparative proteome analysis using the MS intensity-based and label-free method allowed us to estimate relative abundances for 889 proteins during the greening process of rice seedlings. By the comparison with the results of transcriptome analysis, several proteins appeared to be regulated at the translation step or the degradation process of the proteins. Based on these results, we will discuss the potential of proteomics as a tool for screening novel proteins involved in signal responses in plants.
