Two medicinal molecules Hydralazine and Isoniazid have the potential to control wheat crown rot by combing with a N-acetyltransferase FDB2

Fusarium pseudograminearum is the main pathogen that causes wheat crown rot (WCR), causing serious harm to wheat production. Wheat secretes Benzoxazolinones (Bxs) as fungicidins to prevent F. pseudograminearum infection. Fusarium Detoxification of Bx 2 (FDB2) can degrade Bx to non-fungitoxic N-(2-hydroxyphenyl) malonamic acid. Therefore, FDB2 may be a potential drug target for WCR.

In the present study, the structure of FDB2 was determined using the molecular replacement method. The overall FDB2 structure displayed a typical N-acetyltransferase (NAT1) conformation. Unlike other NAT1s, the active site cleft is divided into two parts by a long loop (A¹³⁵MSPYPDVRKNQA¹⁴⁷). Hydralazine, Isoniazid, and 2,4′-dibromoacetanilide were screened out as potential inhibitors of FDB2 by structure alignment. Affinity measurements by MST showed that FDB2 prefers to combine Isoniazid and Hydralazine rather than its natural substrate, 2-aminophenol. Wheat seedling infection assays showed that Isoniazid and Hydralazine suppress F. pseudograminearum invasion in wheat. Our study found that Hydralazine and Isoniazid have the potential to control WCR. This article provides a new idea for the application of medicine, which has serious adverse effects, on plant disease control to reduce research costs and make obsolete drugs shine with vitality.