【Objectives】In this study, the wild type (WT) and the transgenic rice carrying TsIPK2 gene were evaluated to clarify responsive characteristics of rice under salt stress.【Methods】The seeds and 3-leaves-old seedlings of the transgenic rice and the WT were subjected to the solutions containing concentrations of NaCl 0, 50, 100, 150, 200 mmol/L, and physiologically profiled by investigating the seed germination rate, main root and shoot length, MDA and proline content,SOD, POD and CAT activity, and the relative expression of target genes associated with salt stress.【Results】The results showed that the germination rate, main root length and shoot height in the transgenic rice were significantly higher than those in the wild type. Although the accumulations of proline and MDA in the two types were increased, the MDA contents in transgenic type were lower than that in the wild type. While the accumulation of proline in the transgenic rice was significantly higher than that in the wild type under salt stress. Meanwhile, under the salt stress treatment, the activity of SOD in the transgenic rice was much higher than that in the wild type, but the POD activity increased firstly and then decreased without obvious differences in both the transgenic rice and the wild type, and the CAT activity demonstrated similar trends in both the transgenic rice and the wild type. High-salt stress induced up-regulation of five stress-responsive genes at transcriptional level, in which, the expressions of the OsP5CS1, OsSOD, OsCATB and OsLEA3 were significantly increased in transgenic rice compared with the wild type except for the OsPOX1.【Conclusions】This study demonstrates that the overexpression of the TsIPK2 gene improved the salt tolerance in rice via participating in the regulations of compatible solutes, antioxidant capacity and expressions of the stress-responsive genes.
Plant Nutrition and Fertilizer Science