Shotgun Proteomic Analysis of Germinated Rice (Oryza sativa L.) under Salt Stress

Abstract

Rice (Oryza sativa L.) is an important staple crop that feeds more than one half of the world’s population. However, salt stress caused a dramatic decline of rice production. Proteome study of salt tolerant mechanism supplied a span-new viewpoint and valuable clue to rice tolerant improvement. In this study, the salt tolerant capacity and stress response proteins of seven Thai rice cultivars at the germination stage were determined. Pathumthani, Phitsanulok2, RD29, RD31, RD41, RD47, and Riceberry rice cultivars were germinated under 200 mm NaCl for 4 days. Based on germination rate, Pathumthani, Phitsanulok2 and RD31 cultivars were categorized as tolerant, while RD29, RD41 and Riceberry were moderately tolerant and RD47 as susceptible. Shotgun proteome analysis of total proteins prepared from 7 rice seeds grown under salt stress identified 1339 proteins, 51 of which were expressed only in salt tolerant cultivars including Pathumthani, Phitsanulok2 and RD31. These proteins played role in development, protein modification, signal transduction, stress response, transport and transcription. Proteome mechanism during the process of seed germination under salt stress was proposed. This data may be used for not only improvement of rice yield under salinity stress but also enhancing salinity stress tolerance in this important crop.