NaHS引发提高裸燕麦种子活力的生理机制

硫化氢（H₂S）信号在作物种子萌发中发挥着重要作用。为探讨外源H₂S供体NaHS引发提高作物种子活力的作用及其生理机制，以裸燕麦种子为材料，分别用不同浓度NaHS （0、50、100、200、400、800、1600 μmol·L^-1）引发18 h和800 μmol·L^-1 NaHS引发不同时间（6、9、12、15、18、21 h），分析其发芽势（GP）、发芽率（GR）、发芽指数（GI）、活力指数（VI）和幼苗干重（DW）的变化，以确定适宜的NaHS引发浓度和引发时间。以未引发种子为对照（CK），同时设置H₂O引发，研究800 μmol·L^-1 NaHS引发18 h对种子H₂S产生、贮藏物质含量和活性氧代谢的影响。结果表明，800 μmol·L^-1 NaHS引发18 h可显著提高裸燕麦种子的GP、GR、GI和VI，但对DW的影响不大。NaHS引发对种子淀粉、可溶性糖、可溶性蛋白质、还原型抗坏血酸（ASA）、脱氢抗坏血酸（DHA）含量及ASA/DHA和抗坏血酸过氧化物酶活性无显著影响，但显著提高H₂S和氧化型谷胱甘肽（GSSG）含量及细胞色素氧化酶（COX）、超氧化物歧化酶、过氧化氢酶和过氧化物酶活性，分别比CK提高了113.5%、14.4%、103.3%、6.1%、112.0%和120.5%；降低α-淀粉酶和β-淀粉酶活性及超氧阴离子、过氧化氢、丙二醛、还原型谷胱甘肽（GSH）含量、GSH/GSSG和质膜相对透性，分别下降了39.8%、53.6%、34.7%、36.1%、37.6%、29.2%、38.1%和11.9%。由此表明，NaHS引发可能通过提高种子H₂S含量，从而调控抗氧化系统和激活COX活性，降低活性氧对质膜的损伤，增强细胞有氧呼吸代谢，提高裸燕麦种子活力。

Physiological mechanism of NaHS priming improvement of seed vigor in naked oat

Hydrogen sulfide(H2S)plays an important role in the germination of crop seeds.This research explored the role of an exogenous H2S donor,NaHS,as a priming agent for increasing seed vigor and its physiological mechanism.Naked oat seeds were used as the test material,and primed with different concentrations of NaHS(0,50,100,200,400,800 and 1600μmol·L-1)for 18 h and with 800μmol·L-1NaHS for different times(6,9,12,15,18,and 21 h).The germination potential(GP),germination rate(GR),germination index(GI),vitality index(VI)and seedling dry weight(DW)were analyzed to determine the appropriate NaHS priming concentration and priming time.Compared with non-priming of seeds,the effects of 800μmol·L-1NaHS priming for18 h on H2S production,storage substance content and active oxygen metabolism of seeds were studied.The results showed that800μmol·L-1NaHS priming for 18 h could significantly increase the GP,GR,GI,and VI of naked oat seeds,but had no significant effect on DW.NaHS priming had no significant effect on the starch,soluble sugar,soluble protein,reduced ascorbic acid(ASA),dehydroascorbic acid(DHA)contents,ASA/DHA,and ascorbic peroxidase activity of seeds,but significantly increased H2S and oxidized glutathione(GSSG)contents,cytochrome oxidase(COX),superoxide dismutase,catalase and peroxidase activities by 113.5%,14.4%,103.3%,6.1%,112.0%and 120.5%,respectively;Decreasedα-amylase andβ-amylase activities and superoxide anion,hydrogen peroxide,malondialdehyde,reduced glutathione(GSH)contents,GSH/GSSG and plasma membrane relative permeability by 39.8%,53.6%,34.7%,36.1%,37.6%,29.2%,38.1%and 11.9%,respectively.These results indicate that NaHS priming may increase the H2S content of the seeds,thereby regulating the antioxidant system and activating COX activity,reducing the damage caused by reactive oxygen species to the plasma membrane,enhancing cell aerobic respiration metabolism,and improving the vitality of naked oat seeds.