Figure 7.

Proteomics of PEG fractionated soluble and peripheral thylakoid proteins of rice leaves after 72 h of water-stress treatment in light. Five-day old etiolated seedlings were subject to water-stress as in Fig. 1. The 2D gel of control and treated samples were done several times till a consistent pattern was obtained. (A) Representative 2-D gel of PEG fractionated soluble proteins of control rice seedlings, (B) functional category distribution of 34 down-regulated and (C) 25 up-regulated differentially expressed proteins based on actual number of identified proteins. Soluble proteome was isolated and PEG fractionated in two steps; first upto 10% and later upto 20% to remove abundant proteins e.g. Rubisco. Protein (800 µg) from supernatant was treated with G-Biosciences Perfect Focus kit to remove impurities; the obtained pellet was air dried and dissolved in rehydration buffer. After rehydration, isoelectric focusing of proteins was done on a 17 cm IP strip overnight; strip was equilibrated and second dimension was run on a 12.5% SDS-PAGE. 2-D gel was stained with Coomassie Brilliant Blue (CBB), Imaged with UMAX PowerLook 2100XL Image Scanner. Spots were detected, and matched with the Image Master-2D Platinum 6.0 software to get differentially expressed proteins. Numbered spots showing down-regulated proteins in the representative gel from control seedlings are mentioned in text and tables starting with CBC3.