State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, Forestry College, Guangxi University, Nanning, Guangxi, China.
Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
Ecotoxicol Environ Saf. 2022 Aug;241:113748. doi: 10.1016/j.ecoenv.2022.113748. Epub 2022 Jun 10.
Forest ecosystems play an important role in environmental protection and maintaining ecological balance. Understanding the physiological mechanisms of tree species response to aluminum (Al) toxic is crucial to reveal the main causes of plantation decline in acid rain area. As an important afforestation tree species in tropical and subtropical areas, Eucalyptus has high economic value and plays crucial ecological roles. However, continuous fertilization and acid precipitation can exacerbate soil acidification and increase soil active Al, which has a significant negative impact on Eucalyptus growth. Hence, species and genotypes with high Al resistance are required to solve the problem of Al toxicity of acidic soils for sustainable forest production. In this study, E. urophylla was better adapted to Al stress than E. grandis or E. tereticornis; its high Al resistance was attributed to greater antioxidant enzyme activity and non-enzymatic antioxidant content, and a lower degree of membrane lipid peroxidation than E. grandis or E. tereticornis. The differences in adaptability among the three pure species were attributed to their distinct habitats. Eucalyptus urophylla × E. grandis inherited the outstanding adaptability to Al stress from its maternal species (E. urophylla), indicating that Al tolerance is highly heritable and can be selected in Eucalyptus breeding. Our results indicated that the response of Eucalyptus to Al stress may fluctuate according to the time under stress, and might be related to dynamic changes in ROS elimination and accumulation.
森林生态系统在环境保护和维持生态平衡方面发挥着重要作用。了解树种对铝（Al）毒性的生理机制对于揭示酸雨地区种植林衰退的主要原因至关重要。桉树作为热带和亚热带地区的重要造林树种，具有很高的经济价值和重要的生态作用。然而，持续的施肥和酸沉降会加剧土壤酸化，增加土壤活性 Al，这对桉树的生长有很大的负面影响。因此，需要具有高耐铝性的物种和基因型来解决酸性土壤中 Al 毒性问题，以实现可持续的森林生产。在这项研究中，尾巨桉比尾叶桉或赤桉更能适应 Al 胁迫；其较高的 Al 抗性归因于较高的抗氧化酶活性和非酶抗氧化剂含量，以及较低的膜脂过氧化程度。这三个纯树种之间适应性的差异归因于它们不同的栖息地。尾巨桉×尾叶桉从其母本（尾巨桉）遗传了对 Al 胁迫的优异适应性，表明 Al 耐受性具有高度的遗传性，可以在桉树的选育中进行选择。我们的研究结果表明，桉树对 Al 胁迫的反应可能会根据胁迫下的时间而波动，可能与 ROS 消除和积累的动态变化有关。
