Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, 571158, China.
State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-sen University, Shenzhen, 518107, China.
Plant Physiol Biochem. 2023 Jun;199:107747. doi: 10.1016/j.plaphy.2023.107747. Epub 2023 May 6.
Laguncularia racemosa (L.) C.F. Gaertn is a controversial species in China, in terms of being a pioneer species for mangrove restoration and a putative invasive species occupying natural habitats. The tolerance to chilling stress allows L. racemosa to adapt to extreme climate change. However, little is known about the molecular-level chilling resistance mechanisms in L. racemosa, which restricts our understanding of its biological features and invasion potential. In this study, L. racemosa seedlings were treated with freezing temperature (0 °C) at four durations (0 h, 3 h, 12 h and 24 h of recovery after treatment), and both physiological and transcriptional regulations underlying chilling stress resistance were investigated. Chilling stress caused damage to the cell membrane system and reduced photosynthesis efficiency of L. racemosa seedlings. To combat the adverse impacts, plasma membrane biosynthesis and antioxidant processes were substantially enhanced. After 24 h of recovery, the seedlings nearly recovered to normal growth condition, except for the processes related to photosynthesis, indicating their vigorous adaptation to short-term chilling stress. Importantly, the individuals from higher latitude displayed better adaptation to chilling injury than those from lower latitude, highlighting the role of long-term heredity × environment interactions in promoting the chilling resistance capacity of L. racemosa. These features allow L. racemosa to survive in extremely cold weather, but may also increase its risk of invasion into intertidal ecosystems. Together, our findings present a comprehensive view of the chilling-adaptative mechanisms of L. racemosa, which provide clues for better evaluating the invasive potential of L. racemosa.
拉关木（Laguncularia racemosa (L.) C.F. Gaertn）在中国是一种有争议的物种，它既是红树林恢复的先锋物种，也是占据自然栖息地的潜在入侵物种。对冷胁迫的耐受性使拉关木能够适应极端的气候变化。然而，对于拉关木的分子水平耐寒机制知之甚少，这限制了我们对其生物学特征和入侵潜力的理解。在这项研究中，对拉关木幼苗进行了 0°C 的冷冻温度处理，持续时间分别为 0 h、3 h、12 h 和处理后 24 h 的恢复时间，并研究了冷胁迫下的生理和转录调控机制。冷胁迫对细胞膜系统造成损害，降低了拉关木幼苗的光合作用效率。为了应对不利影响，质膜生物合成和抗氧化过程得到了显著增强。24 h 恢复后，幼苗几乎恢复到正常生长状态，除了与光合作用相关的过程外，这表明它们对短期冷胁迫具有很强的适应性。重要的是，来自高纬度地区的个体比来自低纬度地区的个体对冷胁迫损伤具有更好的适应性，这突出了长期遗传×环境相互作用在促进拉关木耐寒能力方面的作用。这些特征使拉关木能够在极冷的天气中存活，但也可能增加其入侵潮间带生态系统的风险。总之，我们的研究结果提供了拉关木耐寒适应机制的全面视图，为更好地评估拉关木的入侵潜力提供了线索。
