Hydrogen-rich water alleviates salt stress in rice during seed germination

This study investigated the molecular mechanism of hydrogen-rich water (HRW)-mediated enhancement of tolerance against salinity stress during rice seed germination. A combination of physiological and molecular approaches was used to study the effect of HRW on the alleviation of salinity stress. A 100-mM NaCl stress caused the increase of H-2 release in germinating rice seeds. With respect to samples treated with 100 mM NaCl alone, exogenous HRW pretreatments differentially attenuated the inhibition of seed germination and seedling growth caused by salinity. Further results showed that both 50 % (in particular) and 100 % concentration of HRW could activate alpha/beta-amylase activity, thus accelerating the formation of reducing sugar and total soluble sugar. HRW also enhanced total, isozymatic activities or corresponding transcripts of antioxidant enzymes, including superoxide dismutase, catalase, and ascorbate peroxidase. These results were confirmed by the alleviation of oxidative damage, as indicated by a decrease of thiobarbituric acid reactive substances. Additionally, the ratio of potassium (K) to sodium (Na) in both the shoot and root parts was increased. Together, our results suggested that exogenous HRW treatment on rice seeds may be a good option to alleviate salinity stress.