NaCl induced changes in the ionic and osmotic components in rice cultivars vis-a-vis that in a natural halophyte

Although accumulation of osmolytes like proline and glycinebetaine is well known phenomenon in plants under salt stress, the report on influence of salinity on accumulation osmolytes is scarce in halophytes, which grow in saline habitat. Hence, the present study was designed to address the same with aim to identify any commonness in the salt tolerance mechanism operative in glycophytes and halophytes considering salt-sensitive and -tolerant rice cultivars, Badami and Pokali, respectively as glycophytes and Suaeda maritima as halophyte. The study revealed accumulation of Na+ in both the rice cultivars and S. maritima upon application of NaCl, but while NaCl promoted the growth of S. maritima, it inhibited the growth of the rice cultivars. However, the growth of Badami was inhibited more severely than that of Pokali. Estimation of accumulation of osmolytes, such as proline and quaternary ammonium compound (QAC) revealed that both the rice cultivars accumulated proline, but only Pokali accumulated QAC highly significantly. The accumulation of QAC was even greater in S. maritima. Expression analysis of the genes involved in synthesis of proline and glycinebetaine suggested the latter to be the most probable compound protecting Pokali and S. maritima against osmotic stress.

Author : SA Gharat and BP Shaw*