Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation, Nanning, 530004, China.
Guangxi Key Laboratory of Forest Ecology and Conservation, Nanning, 530004, China.
BMC Plant Biol. 2024 Oct 23;24(1):997. doi: 10.1186/s12870-024-05723-z.
As an efficient and high-quality additive in agriculture and forestry production, silicon (Si) plays an important role in alleviating heavy metal stress and improving plant growth. However, the alleviating effect of aluminum (Al) toxicity by Si in Eucalyptus is still incomplete.
Here, a study was conducted using two Al concentrations (0 and 4.5 mM) with four Si concentrations (0, 0.5, 1, and 1.5 mM) to investigate plant growth, tolerance and antioxidant defense system in four Eucalyptus species (Eucalyptus tereticornis, Eucalyptus urophylla, Eucalyptus grandis, and Eucalyptus urophylla × Eucalyptus grandis). The results showed that the stress induced by 4.5 mM Al increased oxidative damage, disturbed the balance of enzymatic and non-enzymatic antioxidant systems, and negatively affected plant growth and tolerance quality in the four Eucalyptus species. However, the addition of 0.5 mM and 1 mM Si alleviated the effects of Al toxicity on plant growth and improved plant growth quality by strengthening stress tolerance. Besides, adding Si significantly facilitated the synergistic action of enzymatic and non-enzymatic antioxidant defenses, increased the removal of reactive oxygen species, reduced lipid peroxidation, and oxidative stress, and promoted the phytoremediation rate of the four Eucalyptus species by 18.7 ~ 34.8% compared to that in the absence of Si.
Silicon can alleviate the effect of Al toxicity by enhancing the antioxidant capacity and improving plant growth and tolerance quality. Hence, the application of Si is an effective method for the phytoremediation of Eucalyptus plantations in southern China.
硅（Si）作为农业和林业生产中的一种高效、高质量添加剂，在缓解重金属胁迫和促进植物生长方面发挥着重要作用。然而，硅对桉树缓解铝（Al）毒性的作用尚不完全。
本研究采用两种铝浓度（0 和 4.5 mM）和四种硅浓度（0、0.5、1 和 1.5 mM），研究了 4 种桉树（尾叶桉、巨桉、尾巨桉和尾赤桉）的生长、耐性和抗氧化防御系统。结果表明，4.5 mM Al 胁迫增加了氧化损伤，扰乱了酶和非酶抗氧化系统的平衡，对 4 种桉树的生长和耐性质量产生了负面影响。然而，添加 0.5 mM 和 1 mM Si 缓解了 Al 毒性对植物生长的影响，通过增强胁迫耐性提高了植物生长质量。此外，添加 Si 显著促进了酶和非酶抗氧化防御系统的协同作用，增加了活性氧的清除，降低了脂质过氧化和氧化应激，与不添加 Si 相比，促进了 4 种桉树的植物修复率提高了 18.7%~34.8%。
硅可以通过增强抗氧化能力和提高植物生长和耐性质量来缓解 Al 毒性的影响。因此，硅的应用是中国南方桉树人工林植物修复的有效方法。
