*Corresponding: fengchen@henau.edu.cn; zhangning88012@126.com.

Agronomy College, Henan Agricultural University, 218 Ping’An Road, Zhengzhou 450046, China

Fusarium crown rot (FCR) is one of the most serious soil-borne diseases in common wheat and have caused major wheat yield losses worldwide. It is crucial to isolate resistance genes for improving wheat FCR resistance. Here, through a combination of transcriptome, VIGS (virus-induced gene silencing) and GWAS (genome-wide association analysis) analysis, we identified an 18.6 kDa heat-shock protein gene (TaHSP18.6) associated with wheat FCR.

Overexpression lines and ethyl methanesulfonate (EMS) mutants revealed TaHSP18.6 positively regulating FCR resistance. Next, we screened a lysine de-acetylase sirtuin-like (TaSRT1) to interact with TaHSP18.6. We further demonstrated that TaSRT1 de-acetylated TaHSP18.6, thereby inhibiting the accumulation of TaHSP18.6 protein. Overexpression lines and EMS mutants showed that the TaSRT1 gene negatively regulated wheat FCR resistance.

Meanwhile, we identified the TaHSP18.6 interacting with an auxin-responsive protein IAA1 (TaIAA1) that negatively regulated FCR resistance. TaHSP18.6-overexpressed lines significantly increased auxin content. Subsequently, exogenous application of auxin sharply enhanced wheat FCR resistance. Taken together, we brought forth a TaSRT1-TaHSP18.6 model regulating wheat FCR resistance possibly through mediating auxin signaling.