Li Longna, Liu Yuhao, Wang Shu, Zou Jianxin, Ding Wenjiang, Shen Wenbiao
Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
Center of Hydrogen Science, Shanghai Jiao Tong University, Shanghai, China.
Front Plant Sci. 2020 Dec 9;11:595376. doi: 10.3389/fpls.2020.595376. eCollection 2020.
Magnesium hydride (MgH) is a promising solid-state hydrogen source with high storage capacity (7.6 wt%). Although it is recently established that MgH has potential applications in medicine because it sustainably supplies hydrogen gas (H), the biological functions of MgH in plants have not been observed yet. Also, the slow reaction kinetics restricts its practical applications. In this report, MgH (98% purity; 0.5-25 μm size) was firstly used as a hydrogen generation source for postharvest preservation of flowers. Compared with the direct hydrolysis of MgH in water, the efficiency of hydrogen production from MgH hydrolysis could be greatly improved when the citrate buffer solution is introduced. These results were further confirmed in the flower vase experiment by showing higher efficiency in increasing the production and the residence time of H in solution, compared with hydrogen-rich water. Mimicking the response of hydrogen-rich water and sodium hydrosulfide (a hydrogen sulfide donor), subsequent experiments discovered that MgH-citrate buffer solution not only stimulated hydrogen sulfide (HS) synthesis but also significantly prolonged the vase life of cut carnation flowers. Meanwhile, redox homeostasis was reestablished, and the increased transcripts of representative senescence-associated genes, including and , were partly abolished. By contrast, the discussed responses were obviously blocked by the inhibition of endogenous HS with hypotaurine, an HS scavenger. These results clearly revealed that MgH-supplying H could prolong the vase life of cut carnation flowers via HS signaling, and our results, therefore, open a new window for the possible application of hydrogen-releasing materials in agriculture.
氢化镁（MgH）是一种很有前景的固态氢源，具有高储氢容量（7.6 wt%）。尽管最近已证实MgH在医学上有潜在应用，因为它可持续地供应氢气（H₂），但其在植物中的生物学功能尚未被观察到。此外，缓慢的反应动力学限制了其实际应用。在本报告中，MgH（纯度98%；粒径0.5 - 25μm）首次被用作切花采后保鲜的氢气产生源。与MgH在水中的直接水解相比，引入柠檬酸盐缓冲溶液时，MgH水解产氢效率可大大提高。在花瓶实验中进一步证实了这些结果，与富氢水相比，MgH - 柠檬酸盐缓冲溶液在提高溶液中H₂的产生量和停留时间方面效率更高。模仿富氢水和硫氢化钠（一种硫化氢供体）的反应，后续实验发现MgH - 柠檬酸盐缓冲溶液不仅刺激了硫化氢（H₂S）的合成，还显著延长了康乃馨切花的瓶插寿命。同时，重新建立了氧化还原稳态，包括[具体基因1]和[具体基因2]在内的代表性衰老相关基因转录本的增加部分被消除。相比之下，用次牛磺酸（一种H₂S清除剂）抑制内源性H₂S明显阻断了上述反应。这些结果清楚地表明，MgH供应H₂可通过H₂S信号延长康乃馨切花的瓶插寿命，因此我们的结果为释氢材料在农业中的可能应用打开了一扇新窗口。
