Overexpression of TaPSKR1L-6A improves resistance to sharp eyespot and increases lignin accumulation in wheat

The soil-borne fungi <i>Rhizoctonia cerealis</i> is one of the major pathogens for the economically-important diseases sharp eyespot of common wheat (<i>Triticum aestivum</i>). Certain <i>phytosulfokine receptor 1</i> (<i>PSKR1</i>) genes mediate resistance to diseases caused by biotrophic/hemibiotrophic pathogens in several plant species. Yet, none of wheat <i>PSKR1</i> genes with positive effect on the innate immune responses to <i>R. cerealis</i> has been reported. Here, we characterize the phytosulfokine receptor 1-like gene TaPSKR1L-6A on wheat chromosome 6A, and determined functional role of it in wheat defense against <i>R. cerealis</i>. We used RNA-seq, BSMV-induced gene silencing and transgenic wheat to investigate the role of TaPSKR1L-6A in resistance to <i>R. cerealis</i>. The results showed that TaPSKR1L-6A has a resistance effect on <i>R. cerealis</i>. Transcription analysis showed that its expression level was upregulated when infected with sheath blight. Overexpression of TaPSKR1L-6A significantly increased sheath blight resistance, upregulated the expression of lignin synthesis and metabolism pathway genes, and increased lignin accumulation, which was opposite to the results of silencing TaPSKR1L-6A. Collectively, these results clearly suggest that TaPSKR1L-6A mediates resistance to sharp eyespot by activating the expression of several lignin synthesis-related genes and increasing lignin accumulation. Thus, <i>TaPSKR1L-6A</i> is a promising gene for improving wheat resistance against sharp eyespot. This study sheds light on wheat defense mechanisms against <i>R. cerealis</i>.