Abstract：
Hydrogen sulfide (H2S) application impacts on endogenous H2S, reactive oxygen species (ROS), and reactive nitrogen species (RNS) in cold-stored peach fruit were investigated. 20 μL L-1 H2S (NaHS as the donor) efficiently retarded the quality deterioration arising from chilling injury (CI), triggering endogenous H2S production, while enhancing antioxidant systems and ROS generation (NADPH oxidative enzyme). H2S promoted nitric oxide (NO) correlated with the S-nitrosoglutathione reductase (GSNOR)-mediated GSNO reduction, while suppressing the peroxynitrite anion content. As the pivotal coenzyme of ROS and RNS, nicotinamide adenine dinucleotide phosphate (NADPH) levels were elevated by H2S during late-stage storage via the tricarboxylic acid cycle, where reduced NADP-isocitrate dehydrogenase (NADP-ICDH) activity and gene expression. Structural analysis of peach NADP-ICDH (UniProtKB M5WXP5) deduced that Cys79 and Tyr396 are the likeliest targets for S-nitrosylation and nitration, respectively. These results indicate that H2S counteracts the disorders of ROS and RNS to ameliorate CI of peach fruit.
摘要：
硫化氢（H2S）的应用对内源性H2S的影响，活性氧（ROS），研究了冷藏桃果实中的活性氮物种（RNS）。20μL-1H2S（NaHS作为供体）有效地延缓了冷害（CI）引起的质量恶化，引发内源性H2S产生，同时增强抗氧化系统和ROS生成（NADPH氧化酶）。H2S促进一氧化氮（NO）与S-亚硝基谷胱甘肽还原酶（GSNOR）介导的GSNO还原相关，同时抑制过氧亚硝酸盐阴离子含量。作为ROS和RNS的关键辅酶,烟酰胺腺嘌呤二核苷酸磷酸（NADPH）水平在通过三羧酸循环的后期储存期间被H2S升高，其中NADP-异柠檬酸脱氢酶(NADP-ICDH)活性和基因表达降低。桃子NADP-ICDH（UniProtKBM5WXP5）的结构分析推断，Cys79和Tyr396是S-亚硝基化和硝化的最可能靶标，分别。这些结果表明，H2S可以抵消ROS和RNS的紊乱，从而改善桃果的CI。
