An Isoflavone Synthase Gene in Responds to Infection Causing Web Blotch.

Peanut web blotch is an important leaf disease caused by , which seriously affects the quality and yield of peanuts. However, the molecular mechanisms of peanut resistance to peanut web blotch are not well understood. In this study, a transcriptome analysis of the interaction between peanut () and revealed that total 2989 (779 up- and 2210 down-regulated) genes were all differentially expressed in peanut leaves infected by at 7, 14, 21 days post inoculation. The pathways that were strongly differentially expressed were the flavone or isoflavone biosynthesis pathways. In addition, two 2-hydroxy isoflavanone synthase genes, IFS1 and IFS2, were strongly induced by infection. Overexpression of the two genes enhanced resistance to in . Knockout of genes in peanut reduced disease resistance to . These findings demonstrated that genes play key roles in peanut resistance to infection. Promoter analysis of the two genes showed several defense-related cis-elements distributed in the promoter region. This study improves our understanding of the molecular mechanisms behind resistance of peanut infection by , and provides important information that could be used to undertake greater detailed characterization of web blotch resistance genes in peanut.