Hydrogen rich water (HRW) induces plant growth and physiological attributes in fragrant rice varieties under salt stress

Abstract Hydrogen is an important molecule, exerting antioxidant ability in plants and animals through antioxidant enzymes, which can be dissolved in water. Previous studies have showed that application of hydrogen rich water (HRW), containing a high concentration of hydrogen, plays an important role in enhancing drought tolerance and alleviating the metal stress in plants. However, the effects of HRW on plant growth and physiological attributes in fragrant rice varieties under salt stress are still unclear. A pot experiment was conducted with two fragrant rice varieties i.e. Yuxiangyouzhan and Xiangyaxiangzhan to study the effects of HRW treatments i.e. foliar application of HRW (F-HRW) and irrigation application of HRW (I-HRW) on plant growth and physiological attributes under two NaCl levels (0 mmol L -1 and 150 mmol L -1 ). The results depicte d that, compared with without HRW treatment (CK), the F-HRW and I-HRW treatments significantly increased the dry weight per unit seedling height by 12.64% and 22.99%, while decreased the plant height by 3.92% and 2.97% respectively of two fragrant rice varieties under salt stress. Moreover, compared with CK treatment, the activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) were enhanced by F-HRW and I-HRW treatments in NaCl-stressed fragrant rice cultivars and opposite results were observed for MDA content. In crux, our findings conclude that application of HRW modulates the plant growth and physiological attributes in salt-stressed fragrant rice cultivars.