Rice proteomics: ending phase I and the beginning of phase II.

Rice is a critically important food crop plant on our planet. It is also an excellent model plant for cereal crops, and now in position to serve as a reference plant for biofuel production. Proteomics study of rice therefore is crucial to better understand "rice" as a whole. Rice proteomics has moved well beyond the initial proteome analysis in the early to late 1990s. Since the year 2000, numerous proteomic studies have been performed in rice during growth and development and against a wide variety of environmental factors. These proteomic investigations have established the high-resolution 2-D reference gels of rice tissues, organs, and organelle under normal and adverse (stressed) conditions by optimizing suitable, reproducible systems for gel, and MS-based proteomic techniques, which "rejuvenated" the rice proteome field. This constituted the "phase I" in rice proteomics, and resulted in rice being labeled as the "cornerstone" of cereal food crop proteomes. Now, we are in position to state that rice proteomics today marks the "beginning of phase II". This is due to the fact that rice researchers are capable of digging deeper into the rice proteome, mapping PTMs (in particular reversible protein phosphorylation), performing inter- and intra-species comparisons, integrating proteomics data with other "omic" technologies-generated data, and probing the functional aspect of individual proteins. These advancements and their impact on the future of rice proteomics are the focus of this review.