Physiological and comparative proteomic analyses of Thai jasmine rice and two check cultivars in response to drought stress

To understand the molecular responses of Thai jasmine rice (Oryza sativa L. ssp. indica cv. KDML105) under drought, proteomes of KDML105 cultivars and two check cultivars, namely NSG19 (tolerant) and IR20 (sensitive) were investigated. The effect of PEG6000 and mannitol for creating osmotic stress (-0.1 MPa to -2.1 MPa) was tested in KDML105 before applied to the three cultivars. The leaf proteomes were analyzed by GeLC-MS/MS shotgun proteomics. Among 623 proteins identified, 53 proteins showed significant difference in protein expressions, which could be hierarchically classified into three clusters of proteins up-regulated in IR20, NSG19, or in KDML105. Coronatine-insensitive 1 protein that thought to be involved in stomatal closing was prominently observed in NSG19, regarding to its physiology of rapid stomatal closing and highest stability of photosystem II. WD-40 repeat protein which involves in cell death was induced in IR20. On the other hand, H-protein promoter binding factor-2a remarkably increased in KDML105.