Glutathione produced by γ-glutamyl cysteine synthetase acts downstream of hydrogen to positively influence lateral root branching

H2 supplied via ammonia borane stimulates lateral root branching via phytomelatonin signaling

A reliable and stable hydrogen gas (H2) supply will benefit agricultural laboratory and field trials. Here, we assessed ammonia borane (AB), an efficient hydrogen storage material used in the energy industry, and determined its effect on plant physiology and the corresponding mechanism. Through hydroponics and pot experiments, we discovered that AB increases tomato (Solanum lycopersicum) lateral root (LR) branching and this function depended on the increased endogenous H2 level caused by the sustainable H2 supply. In particular, AB might trigger LR primordia initiation. Transgenic tomato and Arabidopsis (Arabidopsis thaliana) expressing hydrogenase1 (CrHYD1) from Chlamydomonas reinhardtii not only accumulated higher endogenous H2 and phytomelatonin levels but also displayed pronounced LR branching. These endogenous H2 responses achieved by AB or genetic manipulation were sensitive to the pharmacological removal of phytomelatonin, indicating the downstream role of phytomelatonin in endogenous H2 control of LR formation. Consistently, extra H2 supply failed to influence the LR defective phenotypes in phytomelatonin synthetic mutants. Molecular evidence showed that the phytomelatonin-regulated auxin signaling network and cell-cycle regulation were associated with the AB/H2 control of LR branching. Also, AB and melatonin had little effect on LR branching in the presence of auxin synthetic inhibitors. Collectively, our integrated approaches show that supplying H2 via AB increases LR branching via phytomelatonin signaling. This finding might open the way for applying hydrogen storage materials to horticultural production.

Molecular hydrogen positively influences lateral root formation by regulating hydrogen peroxide signaling

Although a previous study discovered that exogenous molecular hydrogen (H₂) supplied with hydrogen-rich water (HRW) can mediate lateral root (LR) development, whether or how endogenous H₂ influences LR formation is still elusive. In this report, mimicking the induction responses in tomato seedlings achieved by HRW or exogenous hydrogen peroxide (H₂O₂; a positive control), transgenic Arabidopsis that overexpressed the hydrogenase1 gene (CrHYD1) from Chlamydomonas reinhardtii not only stimulated endogenous hydrogen peroxide (H₂O₂) production, but also markedly promoted LR formation. Above H₂ and H₂O₂ responses were abolished by the removal of endogenous H₂O₂. Moreover, the changes in transcriptional patterns of representative cell cycle genes and auxin signaling-related genes during LR development in both tomato and transgenic Arabidopsis thaliana matched with above phenotypes. The alternations in the levels of GUS transcripts driven by the CYCB1 promoter and expression of PIN1 protein further indicated that H₂O₂ synthesis was tightly linked to LR formation achieved by endogenous H₂, and cell cycle regulation and auxin-dependent pathway might be their targets. There results might provide a reference for molecular mechanism underlying the regulation of root morphogenesis by H₂.

Degradation of Carbendazim by Molecular Hydrogen on Leaf Models

Although molecular hydrogen can alleviate herbicide paraquat and Fusarium mycotoxins toxicity in plants and animals, whether or how molecular hydrogen influences pesticide residues in plants is not clear. Here, pot experiments in greenhouse revealed that degradation of carbendazim (a benzimidazole pesticide) in leaves could be positively stimulated by molecular hydrogen, either exogenously applied or with genetic manipulation. Pharmacological and genetic increased hydrogen gas could increase glutathione metabolism and thereafter carbendazim degradation, both of which were abolished by the removal of endogenous glutathione with its synthetic inhibitor, in both tomato and in transgenic Arabidopsis when overexpressing the hydrogenase 1 gene from Chlamydomonas reinhardtii. Importantly, the antifungal effect of carbendazim in tomato plants was not obviously altered regardless of molecular hydrogen addition. The contribution of glutathione-related detoxification mechanism achieved by molecular hydrogen was confirmed. Our results might not only illustrate a previously undescribed function of molecular hydrogen in plants, but also provide an environmental-friendly approach for the effective elimination or reduction of pesticides residues in crops when grown in pesticides-overused environmental conditions.

A rational synthesis of ultrasmall palladium-based alloys with superhydrophilicity as biocompatible agents and recyclable catalysts

As essential controlling parameters, the local surface area (size distribution) and polarity property of the surface molecules can determine the catalytic activity and biocompatibility directly.

The Applications of Molecular Hydrogen in Horticulture

Improvements in the growth, yield, and quality of horticultural crops require the development of simply integrated, cost-efficient, and eco-friendly solutions. Hydrogen gas (H2) has been observed to have fertilization effects on soils by influencing rhizospheric microorganisms, resulting in improvements in crop yield and quality. Ample studies have shown that H2 has positive effects on horticultural crops, such as promoting root development, enhancing tolerance against abiotic and biotic stress, prolonging storage life, and improving postharvest quality of fruits, vegetables and cut flowers. In this review, we aim to evaluate the feasibility of molecular hydrogen application in horticulture and the strategies for its application, including H2 delivery methods, treatment timing, and the concentration of H2 applied. The discussion will be accompanied by outlining the effects of H2 and the likely mechanisms of its efficacy. In short, the application of H2 may provide novel opportunities for simple and cost efficient improvements of horticultural production in terms of increased yield and product quality but with low carbon dioxide emissions.