State Key Laboratory of Tree Genetics and Breeding, School of Forestry, Northeast Forestry University, Harbin 150040, China.
State Forestry and Grassland Administration Engineering Technology Research Center of Korean Pine, Harbin 150040, China.
Int J Mol Sci. 2023 Feb 20;24(4):4244. doi: 10.3390/ijms24044244.
Saline-alkali stress is a major environmental stress affecting the growth and development of plants such as Although ethylene plays a crucial role in plant response to saline-alkaline stress, its mechanism remains elusive. The mechanism of action of ethylene (ETH) may be related to the accumulation of hormones, reactive oxygen species (ROS), and reactive nitrogen species (RNS). Ethephon is the exogenous ethylene donor. Therefore, for the present study we initially used different concentrations of ethephon (ETH) to treat embryos and identified the best treatment concentration and method to promote the release of dormancy and the germination of embryos. We then analyzed the physiological indexes, including endogenous hormones, ROS, antioxidant components, and reactive nitrogen, in embryos and seedlings to elucidate the mechanism via which ETH manages stress. The analysis showed that 45 mg/L was the best concentration of ETH to relieve the embryo dormancy. ETH at this concentration improved the germination of by 183.21% under saline-alkaline stress; it also improved the germination index and germination potential of the embryos. Further analysis revealed that ETH treatment increased the levels of 1-aminocyclopropane-1-carboxylic acid (ACC), gibberellin (GA), soluble protein, nitric oxide (NO), and glutathione (GSH); increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), nitrate reductase (NR), and nitric oxide synthase (NOS); and decreased the levels of abscisic acid (ABA), hydrogen peroxide (HO), superoxide anion, and malondialdehyde (MDA) of under saline-alkali stress. These results indicate that ETH mitigates the inhibitory effects of saline-alkali stress and provides a theoretical basis by which to establish precise control techniques for the release of seed dormancy of tree species.
盐-碱胁迫是影响植物生长和发育的主要环境胁迫因素之一，如。虽然乙烯在植物对盐-碱胁迫的响应中起着至关重要的作用，但它的作用机制仍不清楚。乙烯（ETH）的作用机制可能与激素、活性氧（ROS）和活性氮（RNS）的积累有关。乙烯利是外源乙烯供体。因此，本研究首先用不同浓度的乙烯利（ETH）处理胚，确定最佳处理浓度和方法，以促进休眠的释放和胚的萌发。然后我们分析了胚和幼苗的生理指标，包括内源激素、ROS、抗氧化成分和活性氮，以阐明 ETH 管理应激的机制。分析表明，45mg/L 是缓解胚休眠的最佳 ETH 浓度。在盐-碱胁迫下，该浓度的 ETH 将胚的萌发率提高了 183.21%；它还提高了胚的发芽指数和发芽势。进一步分析表明，ETH 处理增加了 1-氨基环丙烷-1-羧酸（ACC）、赤霉素（GA）、可溶性蛋白、一氧化氮（NO）和谷胱甘肽（GSH）的水平；提高了超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、硝酸还原酶（NR）和一氧化氮合酶（NOS）的活性；降低了盐-碱胁迫下胚中脱落酸（ABA）、过氧化氢（HO）、超氧阴离子和丙二醛（MDA）的水平。这些结果表明，ETH 减轻了盐-碱胁迫的抑制作用，为建立树种种子休眠释放的精确控制技术提供了理论依据。
