Foliar application of selenium affecting pollen viability, grain chalkiness, and transporter genes in cadmium accumulating rice cultivar: A pot study

Under Cadmium (Cd) stress, rice grain quality and quantity are compromised, affecting human health. Appli-cation of Selenium (Se) mitigating Cd stress in rice was already reported, but its role in rescuing Cd induced damage in the reproductive parts in rice plants has not been studied before. To investigate the underlying mechanism, Se mediated alleviation of Cd-stress induced damage to pollen viability, germination rate, and grain chalkiness were studied. A grain Cd accumulating rice genotype was selected and treated with 10 mu M Cd and sprayed with 5 mu M Se during tillering, elongating and heading stages. A significant reduction in pollen viability, germination percentage, and accumulation of higher amount of ROS in the reproductive parts were observed in Cd treated plants. However, Se supplementation (i.e. Cd + Se), decreased the ROS accumulation in anther, pistil, pollen and enhanced the pollen viability and germination percentage. Cd translocation was prevented from flag leaf to grains, under Se treatment. As a result, a signifi-cantly higher seed setting rate, and yield were observed. Additionally, Se improved grain nutrient content and grain quality. Therefore, the recent study suggests that the use of foliar spray of Se could be a cost-effective strategy to prevent Cd-induced yield loss and quality in rice.

Automated summary

It was found that under Cd stress, rice grain quality and quantity are compromised, affecting human health. Previous research has shown that Selenium (Se) can mitigate Cd stress in rice, but its role in rescuing Cd-induced damage in the reproductive parts of rice plants has not been studied. This study investigated the mechanism of Se-mediated alleviation of Cd-stress induced damage to pollen viability, germination rate, and grain chalkiness. The results showed that Se supplementation decreased ROS accumulation in the reproductive parts, improved pollen viability and germination rate, and prevented Cd translocation from leaves to grains. Therefore, foliar spray of Se could be a cost-effective strategy to prevent Cd-induced yield loss and quality reduction in rice.