Chinese chive usually becomes decayed after a short storage time, which was closely observed with the redox imbalance. To cope with this practical problem, in this report, molecular hydrogen (H₂) was used to evaluate its influence in maintaining storage quality of Chinese chive, and the changes in antioxidant capacity were also analyzed. Chives were treated with 1%, 2%, or 3% H₂, and with air as the control, and then were stored at 4 ± 1 °C. We observed that, compared with other treatment groups, the application of 3% H₂ could significantly prolong the shelf life of Chinese chive, which was also confirmed by the obvious mitigation of decreased decay index, the loss ratio of weight, and the reduction in soluble protein content. Meanwhile, the decreasing tendency in total phenolic, flavonoid, and vitamin C contents was obviously impaired or slowed down by H₂. Results of antioxidant capacity revealed that the accumulation of reactive oxygen species (ROS) and hydrogen peroxide (H₂O₂) was differentially alleviated, which positively matched with 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and the improved activities of antioxidant enzymes, including superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Above results clearly suggest that postharvest molecular hydrogen application might be a potential useful approach to improve the storage quality of Chinese chive, which is partially achieved through the alleviation of oxidative damage happening during the storage periods. These findings also provide potential theoretical and practical significance for transportation and consumption of perishable vegetables.

Molecular hydrogen (H₂) is crucial for agricultural microbial systems. However, the mechanisms underlying its influence on crop yields is yet to be fully elucidated. This study observed that H₂-based irrigation significantly increased strawberry (Fragaria × ananassa Duch.) yield with/without nutrient fertilization. The reduction in soil available nitrogen (N), phosphorus (P), potassium (K), and organic matter was consistent with the increased expression levels of N/P/K-absorption-related genes in root tissues at the fruiting stage. Metagenomics profiling showed the alterations in rhizosphere microbial community composition achieved by H₂, particularly under the conditions without fertilizers. These included the enrichment of plant-growth-promoting rhizobacteria, such as Burkholderia, Pseudomonas, and Cupriavidus genera. Rhizobacteria with the capability to oxidize H₂ (group 2a [NiFe] hydrogenase) were also enriched. Consistently, genes related to soil carbon (C) fixation (i.e., rbcL, porD, frdAB, etc.), dissimilar nitrate reduction (i.e., napAB and nrfAH), and P solublization, mineralization, and transportation (i.e., ppx-gppA, appA, and ugpABCE) exhibited higher abundance. Contrary tendencies were observed in the soil C degradation and N denitrification genes. Together, these results clearly indicate that microbe-mediated soil C, N, and P cycles might be functionally altered by H₂, thus increasing plant nutrient uptake capacity and horticultural crop yield.

Bok choy (Brassica rapa var. chinensis) experiences rapid postharvest quality decline, primarily due to water loss. This study aims to evaluate the effect of H₂-modified atmosphere packaging (MAP; containing 0.01%, 0.1%, and 1% H₂) on extending the shelf life of bok choy. First, we observed that the storage of bok choy for 9 d (4 °C and 85% relative humidity) was accompanied by a decreasing tendency of molecular hydrogen (H₂) production. Subsequently, the effects of hydrogen (H₂) administered via modified atmosphere packaging on the preservation of bok choy were investigated. The results showed that among the treatments, 0.1% H₂ MAP could effectively improve the storage quality of bok choy under identical storage conditions. Compared to the control groups at 9 d, the contents of chlorophyll a/b, carotenoids, total phenols and flavonoids, and total soluble solids were increased by 43.75%, 40%, 27.78%, 28.89%, 102.38%, and 7.29%, and weight loss rate and electrolyte leakage were reduced by 31.77% and 50.19% (p < 0.05). Meanwhile, the combined water fraction was increased and respiration rate was decreased. Biochemical evidence further showed that xyloglucan endotransglycosylase 2/3 (XET2/3) transcripts and xyloglucan endotransglycosylase (XET) activity, responsible for cell wall degradation, were decreased. By contrast, peroxidase 31/37 (POD31/37) genes and peroxidase (POD) activity, key to the synthesis of lignin, were increased. Importantly, these changes were positively matched with the maintenance of cell wall integrity by H₂ MAP. Together, the results clearly suggested that H₂ MAP could maintain the postharvest quality of bok choy via alleviating water loss and maintaining cell wall integrity. These findings thus provide a useful technology for improving the storage quality of vegetables prone to water loss.