Hydrogen Gas Improves Seed Germination in Cucumber by Regulating Sugar and Starch Metabolisms

Abstract

Hydrogen gas (H2), an important gaseous regulator, is involved in various plant growth and development processes. However, there have been few studies on the role of H2 in seed germination. In this study, the role and underlying mechanisms of H2 in enhancing seed germination were investigated in cucumber (Cucumis sativus L.). The results revealed that the germination rate, germ length, germination index, and vitality index of cucumber exhibited a dose-dependent relationship with the increase in concentrations of hydrogen-rich water (HRW, a H2 donor; 0, 1, 10, 25, 50, 75, and 100%), attaining the maximum values with 75% HRW treatment. Treatment with 75% HRW resulted in higher contents of soluble sugar, soluble protein, and starch than the control. Additionally, the activity of α-amylase, β-amylase, and total amylase was significantly improved by 75% HRW treatment compared to the control, reaching the maximum values at 36 h. Moreover, the expression levels of starch-related genes AMY and BMY and sugar-related genes SS4 and SS3 were significantly upregulated by 75% HRW treatment during germination, particularly at 36 h. These results suggest that H2 might promote cucumber seed germination by increasing sugar and starch metabolisms.

Hydrogen‐rich water alleviates chilling injury‐induced lignification of kiwifruit by inhibiting peroxidase activity and improving antioxidant system

“…33 The enhancement of the antioxidant system conferred by H 2 could be the result of triggering signaling such as phytohormones and sugars. 34 HRW improves sugar levels to further feed the antioxidant system Emerging evidence supports the notion that sugars play vital roles in the defense of cold stress in horticultural crops. However, the differential roles of sugars depend on their species.…”

“…Indeed, H 2 has been reported to be involved in phytohormone signaling via regulating their receptor genes in response to stresses 33 . The enhancement of the antioxidant system conferred by H 2 could be the result of triggering signaling such as phytohormones and sugars 34 …”

Effects of Hydrogen-Rich Water on Postharvest Physiology in Scales of Lanzhou Lily during Storage

“…Hydrogen-rich water (HRW) as a H 2 donor was prepared and analyzed from a hydrogen gas generator (QL-300, Saikesaisi Hydrogen Energy Co., Ltd., Shandong, China) and a dissolved hydrogen portable meter (ENH-1000, Trustlex Co., Led, Tokyo, Japan) in reference to Hou et al [45]. In our experiments, a solution with H 2 concentration of 0.45 mM and maintained at a relative constant level at room temperature for at least 12 h was defined as 100% HRW [6]. The prepared HRW was immediately diluted to various concentrations (10%, 50%, and 100%, [v/v]).…”

“…For example, 100% hydrogen-rich water (HRW) could effectively increase the germination efficiency and the concentration of bioactive phytochemicals in black barley [5]. Treatment with 75% HRW promoted the germination of cucumber seeds by increasing the metabolism of sugar and starch [6]. HRW (75%) induced the tolerance of maize seedlings by maintaining redox balance and nutrient balance [7].…”

Nitric Oxide Acts as an Inhibitor of Postharvest Senescence in Horticultural Products

“…H 2 , a new signaling molecule, has been found to be involved in important physiological processes in plants, including germination [ 66 ], lateral and adventitious rooting [ 67 , 68 ], and plant tolerance against abiotic stress [ 69 , 70 , 71 ]. Recently, the roles of H 2 in delaying postharvest senescence have been reported in cut flowers [ 72 , 73 ], fruits [ 74 , 75 ], and vegetables [ 76 , 77 ].…”