PCE：山东农大马方放-包志龙团队揭示H2S通过苹果幼苗中的有机酸周转改善盐胁迫恢复

今天介绍的是山东农大马方放-包志龙团队在PCE发表的研究论文《H2S Improves Salt-stress Recovery via Organic Acid Turn-over in Apple Seedlings》。

H2S在应激生物学中的信号作用已被广泛报道，但其在农艺实践中的应用仍有待于进一步研究。一直以来，对H2S信号中的代谢重分布缺乏定量的解析，因此难以在生化水平上阐明其在应激耐受中的功能。

在本研究中，苹果幼苗首先用盐胁迫处理两周，然后用四种不同浓度的NaHS处理。通过表型分析、13C瞬时标记、靶向代谢和转录组分析等深入研究，作者首次在木本果树作物的幼苗中发现，H2S通过糖酵解和三羧酸循环回收固定碳，从而抑制碳水化合物的徒积累 ，维持有效的CO2 同化，保持平衡的淀粉代谢，产生足够的H2O2，通过H2O2诱导的阴离子通道（铝激活的苹果酸转运蛋白）维持苹果酸/氨基丁酸稳态，并最终改善盐胁迫恢复。

作者的研究结果系统地证明了中央碳代谢在H2S信号传导中的重要作用，并阐明了H2S在苹果幼苗中的作用模式。作者得出结论，H2S信号以自下而上的方式与中心碳代谢相互作用，以在盐胁迫后恢复植物生长。

Signaling roles of H2S in stress biology are widely reported but not sufficiently established to urge its use in agronomic practice. Our lack of quantitative understanding of the metabolic rewiring in H2S signaling makes it difficult to elucidate its functions in stress tolerance on the biochemical level. Here, Malus hupehensis Rehd. var. pingyiensis seedlings, were first treated with salt stress for two weeks and then treated with four different concentrations of NaHS. Via vigorous investigations including phenotypic analysis, 13C transient labeling, targeted metabolic and transcriptomic analysis, for the first time in the seedlings of a woody fruit crop, we find out that H2S recycles fixed carbons through glycolysis and tricarboxylic acid cycle to inhibit futile accumulation of carbohydrates, to maintain an efficient CO2 assimilation, to keep an balanced starch metabolism, to produce sufficient H2O2, to maintain malate/γ-aminobutyric acid homeostasis via a H2O2-induced anion channel (aluminum-activated malate transporter), and eventually to improve salt-stress recovery. Our results systematically demonstrate the vital roles of central carbon metabolism in H2S signaling and clarifies the mode of action of H2S in apple seedlings. We conclude that H2S signaling interacts with central carbon metabolism in a bottom-up manner to recover plant growth after salt stress.

转自：植物科学SCI

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