Using Molecular Docking Develops Plant-Bioactive Compounds as Fungicides Against Tox-A Protein in Wheat Tan Spot Disease

Abstract

Tan spot is a foliar disease of wheat caused by a fungus Pyrenophora tritici-repentis (Ptr) which produce Tox-A protein, results in major yield losses worldwide. Pyrenophora tritici-repentis acquire gene known as Tox-A through horizontal gene transfer from Stagonospora nodorum that code for toxins known as PTRTox-A or PTR necrosis Tox-A. Molecular docking of different bioactive compound, lycopene, zeaxanthin, lutein and vincristine with Tox-A was performed using Patchdock server. The study revealed that various bioactive compounds purified from various medicinal plants were effective against Tox-A protein. Based on Geometric shape complementarity score of first compounds (6560, 6100, 5856, 4748) of each complex, lycopene interacted best with Tox-A protein followed by zeaxanthin, lutein and vincristine. High interactability of lycopene with Tox-A protein of PTR is because of high Geometric shape complementarity (GSC) score, large Interface area (IA) and larger size of Lycopene-Tox-A complex. LEU 161, CYS 160 and PHE 147 are found in the entire three complex (Lycopene-Tox-A, Zeaxanthin-Tox-A and Lutein Tox-A complex). CYS 160 is found in Zeaxanthin-Tox-A and Lutein-Tox-A complex and is involve in Alkyl interaction while in Lycopene-Tox-A complex it involves in Vander Waal interaction. Pi-cation interaction is only limited to Vincristine-Tox-A complex and does not find in any other complex. All the bioactive compounds were screened in order of lycopene>zeaxanthin>lutein>vincristine, based on their interaction with Tox-A protein of Pyrenophora tritici-repentis.