Biological invasion is a hot topic in ecological research. Most studies on the physiological mechanisms of plants focus on leaves, but few studies focus on stems. To study the tolerance of invasive plant (Sphagneticola trilobata L.) to low temperature, relevant physiological indicators (including anthocyanin and chlorophyll) in different organs (leaves and stems) were analyzed, using a native species (Sphagneticola calendulacea L.) as the control. The results showed that, upon exposure to low temperature for 15 days, the stems of two Sphagneticola species were markedly reddened, their anthocyanin content increased, chlorophyll and chlorophyll fluorescence parameters decreased, and the accumulation of reactive oxygen species in the stem increased. The percentage increases of antioxidants and total antioxidant capacities in stems were significantly higher in S. trilobata than in S. calendulacea. This showed that S. trilobata had higher cold tolerance in stems while leaves were opposite. To further verify the higher cold tolerance of the stem of S. trilobata, a defoliation experiment was designed. We found that the defoliated stem of S. trilobata reduced anthocyanin accumulation and increased chlorophyll content, while alleviating membrane lipid damage and electrical conductivity, and the defoliated stem still showed an increase in stem diameter and biomass under low temperature. The discovery of the physiological and adaptive mechanisms of the stem of S. trilobata to low temperature will provide a theoretical basis for explaining how S. trilobata maintains its annual growth in South China. This is of great significance for predicting the future spread of cloned and propagated invasive plants.

中文翻译：

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入侵物种 Sphagneticola trilobata (L.) Pruski 在低温下的非叶器官茎的光合补偿。

生物入侵是生态学研究的热点。植物生理机制的研究多集中在叶上，而对茎的研究少之又少。为研究入侵植物（Sphagneticola trilobata L.）对低温的耐受性，以本地物种（Sphagneticola calendulacea L.）为对照，分析了不同器官（叶和茎）的相关生理指标（包括花青素和叶绿素） . 结果表明，低温暴露15 d后，两种Sphagneticola种的茎明显变红，花青素含量增加，叶绿素和叶绿素荧光参数降低，茎中活性氧的积累增加。S. trilobata 茎中抗氧化剂和总抗氧化能力的增加百分比显着高于 S. calendulacea。这表明三叶草的茎部具有较高的耐寒性，而叶部则相反。为了进一步验证三叶草茎的较高耐寒性，设计了落叶实验。我们发现三叶草脱叶茎减少了花青素的积累，增加了叶绿素含量，同时减轻了膜脂损伤和电导率，并且在低温下脱叶茎仍然表现出茎径和生物量的增加。三叶草茎对低温的生理和适应机制的发现，将为解释三叶草在华南地区如何保持年生长提供理论依据。