Silicon mitigates oxidative stress and has positive effects in Eucalyptus platyphylla under aluminium toxicity

The tolerance to metal toxicity, such as aluminium, can be induced by the formation of Al-Si complexes. Therefore, the aim of this research is to determine the contribution of Si on nutrient concentrations, compounds linked to oxidative stress, photosynthetic pigments and gas exchange and to determine if Si can improve the tolerance mechanism of young Eucalyptus platyphylla plants exposed to Al toxicity. The experimental setup was completely randomized with four treatments (0, 1.6 mmol/L Al, 2.0 mmol/L Si and 1.6 mmol/L Al + 2.0 mmol/L Si; being described as the control, Al toxicity, Si and Al toxicity + Si, respectively). The treatment with Si attenuated the negative effects of Al on nutrient concentrations by reducing superoxide, hydrogen peroxide, malondialdehyde and electrolyte leakage. Pigments and gas exchange exhibited beneficial effects after Si application, with positive interactions also being detected between Si-Al. Therefore, this study demonstrates that Si reduced the oxidative stress and improved the tolerance mechanism of young E. platyphylla plants exposed to Al toxicity.