Boron-resistant Alternaria alternata (OG14) mitigates boron stress by improving physiological and antioxidative response in wheat (Triticum aestivum L.)

Effect of Alternaria alternata (OG14) isolated from a rock lichen (Xanthoria sp.) was investigated on the relief of boron stress in wheat. To determine the tolerance level to B stress, the fungus was grown at increasing boric acid (BA) concentrations in the range of 0.0-2.5 M. No significant change in colony development of the fungus was observed up to 1 M BA application compared to the control but after this dose, it decreased depending on the increase in the BA dose. When the element content of wheat seedlings was evaluated by ICP-MS, BA application increased B content together with Mg, P, K, Fe contents of the seedlings to very high levels compared to the control. However, fungus + BA treatments decreased the content of B and the other elements in the seedlings. The BA applications resulted in an increase in the levels of reactive oxygen species, including H2O2 and O2.as well as lipid peroxidation in the seedlings. However, when the fungal inoculation was performed under the same BA conditions, the levels of these parameters decreased. The fungus inoculation stimulated the activity of all studied enzymes compared to BA applications. BA applications alone increased non - enyzmatic the oxidized ascorbate level more than the reducing ascorbate, leading to a decrease in the AsA/DHA ratio. The results show that A. alternata treatment can mitigate the negative effects of B stress on wheat seedlings by reducing ROS, LPO, B content, increasing the capacity of enzymatic and non-enzymatic antioxidants, and improving root and shoot length.

Automated summary

The effect of Alternaria alternata (OG14) isolated from a rock lichen (Xanthoria sp.) on alleviating boron stress in wheat was studied. The fungus was found to tolerate boric acid (BA) concentrations up to 1 M, beyond which its colony development decreased. BA application significantly increased the contents of boron, magnesium, phosphorus, potassium, and iron in wheat seedlings but the treatment with fungus + BA decreased these element contents. BA application resulted in increased levels of reactive oxygen species and lipid peroxidation in the seedlings, while fungal inoculation under the same BA conditions decreased these parameters. It was observed that A. alternata treatment mitigates the negative effects of B stress on wheat seedlings by reducing ROS, LPO, B content, increasing enzymatic and non-enzymatic antioxidants, and improving root and shoot length.