Differential Physiological Responses to Salt Stress between Salt-Sensitive and Salt-Tolerant Rice Cultivars at the Post-Germination and Seedling Stages.

Soil salinity is a key source of abiotic stress in the cultivation of rice. In this study, two currently cultivated rice species-Zhegeng 78 (salt-tolerant) and Zhegeng 99 (salt-sensitive)-with similar backgrounds were identified and used to investigate their differential responses to salt stress at the post-germination and seedling stages. Quantitative RT-PCR analysis demonstrated that the expression of , , and at the post-germination stage, and the expression of , , and at the seedling stage, were significantly higher in the salt-tolerant Zhegeng 78 compared with those of the salt-sensitive Zhegeng 99 under salt stress. The significantly lower Na net uptake rate at the post-germination and higher K net uptake rates at the post-germination and seedling stages were observed in the salt-tolerant Zhegeng 78 compared with those of the salt-sensitive Zhegeng 99 under salt stress. Significantly higher activity of peroxidase (POD) and the lower hydrogen peroxide (HO) accumulation were observed in the salt-tolerant Zhegeng 78 compared with those of salt-sensitive Zhegeng 99 under salt stress at the seeding stage. The salt-tolerant Zhegeng 78 might be valuable in future cultivation in salinity soils.