Abstract

Molecular hydrogen (H2) exhibits a wide breadth of botanical effects especially in improving the resistance to abiotic stress. However, the primary target is not clear. Bidirectional hydrogenases have been well studied in microbes and alga, but there is a paucity of research in higher plants. Here, we used real-time spectrophotometry, gas chromatography and H2 sensor to detect the H2-evolving and H2-uptake activity of the plasma membrane (PM) vesicles of higher plants. Net H+, Na+ and K+ fluxes were measured using Non-invasive Micro-test Technology (NMT). We found that the PM vesicles of Vigna radiata hypocotyls and Capsicum annuum stems have the ability of both oxidizing and producing H2. This two-way enzymatic activity coupled with the redox of ferricyanide/ferrocyanide and NADH/NAD+. H2 affected the H+ and Na+ fluxes on the surface of V. radiata hypocotyls. These results demonstrate that the PM vesicles of higher plants have the abilities of H2 evolution and absorption. The bidirectional activities may act as a valve to regulate the energy balance in plant cells.