Functional characterization of novel genes of oryza species under salinity

Abstract

Rice (Oryza sativa L.) is the world s most important food crop. To improve the yield under salt stress condition, it is essential to understand the fundamental molecular mechanisms behind stress tolerance in plants. Identifying the salt stress-responsive genes from rice plant and studying their molecular mechanism will enrich our understanding to improve rice tolerance to salinity stress. MADS box and LEA gene family TFs play key regulatory roles in plant growth, development and abiotic stress response. However, knowledge concerning the involvement of rice OsMADS16 and wild rice OC_13330 genes in salinity stress tolerance are largely unknown. In the present study, OsMADS16 and OC_13330 genes were cloned and characterized, that was induced by salinity stress. Subcellular localization analysis of both genes in tobacco leaves indicated that OsMADS16 was localized in the nucleus and OC_13330 was localized in both nucleus and cytosol. OsMADS16 and OC_13330 overexpressing plants showed increased tolerance to salt stress compared with wild-type plants, as are evaluated by higher proline content, total sugar content, chlorophyll content and lower MDA content and Na+/K+ ratio in transgenic plants under salinity stress condition. In addition, OsMADS16 and OC_13330 overexpressing plants also showed increased tolerance to other abiotic stress (osmotic, drought stress, heat, freezing stress, and ABA treatment). These results indicate that OsMADS16 and OC_13330 genes functions as a stress-responsive gene which plays a positive regulatory role in response to salt and other abiotic stress tolerance, and may be used as a candidate gene for salinity stress improvement in plants. newline