Expression of OsBADH1 gene in Indica rice (Oryza sativa L.) in correlation with salt, plasmolysis, temperature and light stresses.

The relationship between environmental factors, salt tolerant and the expression of betaine aldehyde dehydrogenase ( BADH ) gene, salt stress related gene, was investigated in Indica rice. The expression was observed in various rice cultivars as well as under different environmental conditions. Northern blot analysis revealed that salt-tolerant in each rice cultivar is correlated to the expression level of OsBADH1 mRNA. The expression studies showed that OsBADH1 can be induced by a variety of environmental factors such as salinity, drought, cold, heat, light intensity and CO 2 concentration. The results demonstrated that the OsBADH1 mRNA expression was upregulated by salinity, drought, cold and high light intensity but down-regulated by CO 2 enrichment and heat stress. The primary response of OsBADH1 gene expression was induced within 24 h after salinity, cold or drought stress treatment. Moreover, these results suggest that the expression of OsBADH1 gene in response to salt stress could be magnified under high light conditions. Interestingly, the effect of salt stress on the expression of OsBADH1 gene was alleviated by CO 2 enrichment. This report showed that BADH1 gene not only plays role in the response of indica rice to salt stress but also to plasmolysis, temperature and light stresses. Therefore, BADH1 gene might involve in multifunctional mechanisms in response to environmental stresses of indica rice.