Comparative proteome analysis of phosphorus-responsive genotypes reveals the proteins differentially expressed under phosphorous starvation stress in rice

Phosphorus (P)-deficiency is one of the major nutrient constraints for global rice production. P-deficiency tolerance in rice involves complex regulatory mechanisms. To gain insights into the proteins involved in phosphorus acquisition and use efficiency in rice, proteome analysis of a high-yielding rice cultivar Pusa-44 and its near-isogenic line (NIL)-23 harboring a major phosphorous uptake (Pup1) QTL, grown under control and P-starvation stress, was performed. Comparative proteome profiling of shoot and root tissues from the plants grown hydroponically with P (16 ppm, +P) or without P (0 ppm, -P) resulted in the identification of 681 and 567 differentially expressed proteins (DEPs) in shoot of Pusa-44 and NIL-23, respectively. Similarly, 66 and 93 DEPs were identified in root of Pusa-44 and NIL-23, respectively. These P-starvation responsive DEPs were annotated to be involved in metabolic processes like photosynthesis, starch-, sucrose-, energy-metabolism, transcription factors (mainly ARF, ZFP, HD-ZIP, MYB), and phytohormone signaling. Comparative analysis of the expression patterns observed by proteome analysis with that reported at the transcriptome level indicated the Pup1 QTL-mediated post-transcriptional regulation plays an important role under -P stress. Thus, the present study describes the molecular aspect of the regulatory functions of Pup1 QTL under P-starvation stress in rice, which might help develop an efficient rice cultivar with enhanced P acquisition and assimilation for better performance in P-deficient soil.