Phalaenopsis is the most economically important flower crops wildly but hardly tolerated to low-temperature stress. Hydrogen peroxide (H₂O₂), a reactive oxygen species was participated in many chilling-response processes. In this study, the efficiency and mechanism of chilling tolerance induced by transient oxidative shock with H₂O₂ pretreatment were investigated. Phalaenopsis seedlings demonstrated chilling injury when the ambient temperature was at 6°C or lower. Transient oxidative shock by pretreatment with 50 mM H₂O₂ induced chilling tolerance. This pretreatment reduced the leaf electrolyte leakage (EL) from 64.1% to 28.3% of plants cultivated at 6°C for 6 days. Increasing the frequency of H₂O₂ pretreatment from 1 to 3 times strengthened the protective efficiency; however, an H₂O₂ concentration of ≥100 mM caused abnormal leaf morphology such as curl and necrosis. Time-course analysis findings indicated that chilled seedlings pretreated with H₂O₂ had lower EL and malondialdehyde (MDA) content but higher chlorophyll content and better photosynthetic performance, including a higher assimilation rate, maximum quantum yield of photosynthetic system II (Fv/Fm), quantum yield of electron transport (ɸPSII), photochemical quenching (qP), and electron transport rates. The results also demonstrated that pretreatment with 50 mM exogenous H₂O₂ did not alter the endogenous H₂O₂ level only a minor elevation of approximately 2 μmol•g⁻¹ was noted. Under low temperature suffering, activity of catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were increased with fluctuant changes, but CAT and APX inhibited in the low level by H₂O₂ pretreatments. In addition, the significantly high GR activity was reduced the glutathione-to-oxidized glutathione ratio, with peaks occurring at 4-8 h and on day 2 during chilling. Taken together, the findings indicate that exogenous H₂O₂ induced chilling tolerance in Phalaenopsis seedlings, and the process may be involved the glutathione-related oxidant defense system.

蝴蝶兰是经济上最重要的花卉作物，但对低温胁迫难以耐受。过氧化氢 (H ₂ O ₂ )，一种活性氧物质，参与了许多冷响应过程。在本研究中，研究了H ₂ O ₂预处理瞬时氧化休克诱导的耐冷性的效率和机制。当环境温度为 6°C 或更低时，蝴蝶兰幼苗表现出冷害。用 50 mM H ₂ O ₂预处理的瞬时氧化休克诱导耐寒性。这种预处理将在 6°C 下栽培 6 天的植物的叶电解质泄漏 (EL) 从 64.1% 减少到 28.3%。H ₂ O ₂预处理次数从1次增加到3次，保护效率提高；然而，H ₂ O ₂浓度≥100 mM 会导致叶片形态异常，如卷曲和坏死。时程分析结果表明，用 H ₂ O ₂预处理的冷冻幼苗EL 和丙二醛 (MDA) 含量较低，但叶绿素含量较高，光合性能较好，包括较高的同化率、光合系统 II 的最大量子产率 (Fv/Fm)、电子传输的量子产率 (ɸPSII)、光化学猝灭 (qP) ) 和电子传输率。结果还表明，用50 mM 外源性H ₂ O ₂预处理不会改变内源性H ₂ O ₂水平，仅注意到约2 μmol•g ^-1的小幅升高。低温胁迫下，过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）的活性随波动变化而升高，而CAT和APX则被H ₂抑制在低水平O ₂预处理。此外，显着高的 GR 活性降低了谷胱甘肽与氧化型谷胱甘肽的比率，峰值出现在 4-8 小时和第 2 天冷藏期间。综上所述，研究结果表明外源H ₂ O ₂诱导蝴蝶兰幼苗的耐寒性，该过程可能与谷胱甘肽相关的氧化防御系统有关。