Antitranspirant modulates Na+ enrichment and yield in indica rice under salt stress

Rising salinity in agricultural land is a major barrier limiting yields of crops like rice, which has been reported as a salt-sensitive plant. An improvement in salt tolerant ability of rice has been achieved by obstructing the sodium (Na) transpiration flow via apoplastic route. Here we assess the potential of an antitranspirant (AT) in modulating Na enrichment and yield in rice under salt stress. Sodium concentration in flag leaf was enriched in relation to the salt exposure time and significantly decreased in plants grown under 0.2% AT foliar application. Free proline accumulation in salt-stressed plants was increased by 15.3 folds over the control, whereas it was stable in plants grown under 0.2% AT foliar application. Chlorophyll a, chlorophyll b, total chlorophyll, total carotenoids, photon yield of photosystem II (PSII), net photosynthetic rate, transpiration rate, and stomatal conductance in salt-stressed plants were lower than the control with the exogenous foliar spray of 0.2% AT. Positive relationships between total chlorophyll and photon yield of PSII, photon yield of PSII and net photosynthetic rate, and net photosynthetic rate and fertile seed were also evident. Number of seeds per panicle in salt-stressed plants was significantly enhanced by 0.2% AT foliar application, whereas other yield attributes declined. Antitranspirants could be a promising option to improve the growth and yield of rice cultivated on salt-affected soils.