Morphophysiological analysis and expression of proline genes in rice (Oryza sativa L. cv. BRS AG) subjected to in vitro salt stress
Australian Journal of Crop Science
About 20% of the cultivated land and almost half of the irrigated lands of the planet are affected by the salinization of the soil and the water. Rice cultivar BRS AG is the first grown for other purposes than human consumption and can be used in the production of ethanol and animal feed. The objective of this study was to evaluate the germination, morphological characteristics, proline accumulation, and the expression of the genes involved in the metabolism of proline in rice plants, cv. BRS
... e plants, cv. BRS AG, cultured in vitro under salt stress. The plants were cultivated in a culture MS medium with six different NaCl concentrations (0, 32, 68, 102, 136, 170 mM). The germination was evaluated at days 7 and 14, and morphological characteristics were analyzed only at day 21. For proline quantification and expression of the genes required for its metabolism (P5CS1, P5CS2, P5CR, OAT, P5CDH and PDH), two concentrations (136 mM and 0 mM) of NaCl were used, and the samples were collected at days 5, 10, 15, and 20. The results indicate that the growth of rice cv. BRS is completely impaired at 170 mM NaCl, and at 136 mM NaCl. Regarding proline content, in stressed plants, it was higher (1.24 mM g -1 MF) than in the control plants, and was directly related to a high expression observed for the P5CS2 (QR=5.50) and OAT (QR=5.44) genes at 20 days of stress, which explains the high proline concentration at this period. According to the results, rice cultivar BRS AG, is considered tolerant to salt stress.