了解黑河湿地生态系统的健康状况，为黑河湿地的恢复和保护提供一种新的思路和一定的理论基础。以黑河湿地典型植物芦苇为试材，研究了持续干旱条件下叶绿素荧光参数、蛋白质含量及抗氧化酶活性等指标的变化。结果表明，干旱胁迫下，芦苇可溶性蛋白含量表现出先升高后下降的趋势，说明干旱胁迫初期，芦苇机体内启动自我防御功能，诱导出自身的抗旱蛋白，致使芦苇体内可溶性蛋白升高；当干旱胁迫继续加重时，其自身防御系统遭到破坏，可溶性蛋白含量下降。芦苇叶片最小荧光(F0)随干旱胁迫时间的延长而增大，最大荧光(Fm)、光系统II(PSII)最大光化学效率(Fv/Fm)和PSII光合电子传递量子效率(ΦPSII)则下降较明显，说明随着干旱胁迫程度的增加芦苇叶片PSII反应中心的稳定性受到破坏、反应中心传递电子能力下降，光合作用的原初反应受到抑制。干旱胁迫下，芦苇叶片MDA含量持续升高，说明芦苇对于干旱非常敏感，而SOD、POD和CAT酶活性总体呈先升高后降低的趋势，表明干旱胁迫导致芦苇叶片细胞膜膜脂过氧化程度增大，细胞膜受到破坏，最终引起膜结构的损伤，干旱胁迫初期芦苇通过增加抗氧化酶活性来减缓膜损伤，但是随着干旱胁迫的增强，不能阻止干旱带给芦苇的伤害。

In order to understand the health status of the Heihe River wetland ecosystem and provide a theoretical foundation and novel perspectives for its restoration and conservation, this study investigated the changes in chlorophyll fluorescence parameters, protein content, and antioxidant enzyme activities under continuous drought conditions using Phragmites australis, a typical plant of the Heihe River wetland, as the test material. The results showed that the soluble protein content of P. australis increased first and then decreased under drought stress, suggesting that in the early stage of drought stress, the self-defense function of reed body was turned on, which induced its own drought stress protein, leading to the increase of soluble protein content in the body, but when the drought stress level continued to increase, its self-defense system was destroyed, and its soluble protein content decreased. The minimum fluorescence ( F0 ) of P. australis leaves increased with prolonged drought stress, while the maximum fluorescence ( Fm ), photosystem II (PSII) maximum photochemical efficiency (Fv /Fm ), and the quantum efficiency of PSII electron transport (ΦPSII) decreased significantly, indicating that with the increase of drought stress, the stability of PSII reaction center in P. australis leaves was destroyed, the ability of transmitting electron in reaction center was decreased, the primary reaction of photosynthesis was inhibited, and finally the photosynthetic ability of P. australis leaves was decreased. The Malondialdehyde(MDA) content of reed leaves continued to increase under drought stress, indicating high sensitivity of P. australis to drought. The SOD, POD, and CAT enzyme activities showed a trend of increase first and then decrease, indicating that drought stress led to the increase of membrane lipid peroxidation degree of P. australis leaves, the destruction of cell membrane, and finally the damage of membrane structure. Initially, the plant mitigated damage through elevated antioxidant activity, but this defense became ineffective as drought stress intensified.

S564.2；X171.4

中央引导地方科技发展资金项目(22ZY1QA001)；西北中药材全程机械化科研基地建设项目(2109-000000- 20-01-199092)；甘肃省科技厅高等学校科研项目(2017A-085)。