Identifying a promising inhibitor of Fusarium oxysporum f. sp. Lycopersici, Secreted in Xylem 1 protein

Abstract

Fusarium oxysporum f. sp. Lycopersici (FOL) is a soil borne pathogen which infects tomato plants and inflicts severe damage, resulting in heavy yield losses throughout the world. FOL encodes several pathogenicity factors which are necessary for colonizing the host plant and establishing an infection successfully. Secreted in Xylem 1 (SIX1) was chosen for the present study since it is pivotal in determining host specificity and is also involved in pathogenicity/virulence. We predicted the structure of SIX1 by comparative modeling using Robetta server, as the structure of SIX1 is not elucidated. The best possible structure was refined, validated and used for subsequent analysis. In order to identify small molecules which can inhibit FOL, an antifungal library containing 16,824 compounds was screened using the predicted and validated structure. Five antifungal compounds were identified from the library. Ensuing analyses revealed that 4-[[2-(3-methoxyphenoxy) acetyl]amino] benzamide can interact with SIX1 in a stable manner. By inhibiting SIX1 we can inhibit FOL, hence 4-[[2-(3-methoxyphenoxy) acetyl]amino]benzamide is a promising candidate to prevent FOL infection. In addition to biocontrol methods and strategies using transgenic plants overexpressing resistance genes, the usage of small molecule inhibitors involving an integrated approach can be much more effective in combating FOL.