Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, College of Life Sciences, South China Normal University, Guangzhou, 510631, China.
Division of Plant Science, Research School of Biology, College of Science, The Australian National University, Acton, ACT, 2601, Australia.
Photosynth Res. 2021 Aug;149(1-2):121-134. doi: 10.1007/s11120-020-00748-5. Epub 2020 Apr 15.
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.
生物入侵是生态研究中的一个热点。大多数关于植物生理机制的研究都集中在叶片上，但很少有研究关注茎。为了研究入侵植物（三叶委陵菜）对低温的耐受性，分析了不同器官（叶片和茎）中相关的生理指标（包括花青素和叶绿素），以本地种（三叶委陵菜）为对照。结果表明，在低温处理 15 天后，两种委陵菜的茎明显变红，花青素含量增加，叶绿素和叶绿素荧光参数下降，茎中活性氧的积累增加。与三叶委陵菜相比，二色委陵菜茎中抗氧化剂和总抗氧化能力的百分比增加显著更高。这表明三叶委陵菜在茎中具有更高的耐寒性，而叶片则相反。为了进一步验证三叶委陵菜茎的较高耐寒性，设计了去叶实验。我们发现，三叶委陵菜去叶后的茎减少了花青素的积累，增加了叶绿素的含量，同时减轻了膜脂的损伤和电导率，并且去叶后的茎在低温下仍然表现出茎直径和生物量的增加。三叶委陵菜茎对低温的生理和适应机制的发现，为解释三叶委陵菜如何在华南保持其年生长提供了理论基础。这对于预测克隆和繁殖的入侵植物未来的传播具有重要意义。
