Sugar Transporter HmSWEET8 Cooperates with HmSTP1 to Enhance Powdery Mildew Susceptibility in Hance.

The powdery mildew caused by is a serious concern in Hance. Therefore, exploring the mechanisms underlying sugar efflux from host cells to the fungus during the plant-fungus interaction showed great significance. The study successfully cloned and genes based on RNA-seq technology. The complementation assays in yeast EBY.VW4000 found HmSWEET8 and HmSTP1 transporting hexose. Over-expressing or silencing in leaves increased or decreased powdery mildew susceptibility by changing glucose concentration in infective sites. Meanwhile, over-expressing in leaves also increased powdery mildew susceptibility by elevating the glucose content of infective areas. Additionally, expression was up-regulated obviously in over-expressed plants and inhibited significantly in silenced plants. Co-expressing and genes significantly increased powdery mildew susceptibility compared with over-expressed or plants alone. The results demonstrated that HmSTP1 may assist with HmSWEET8 to promote infection. Consequently, the infection caused by resulted in the activation of , leading to an increased transfer of glucose to the apoplasmic spaces at the sites of infection, then, HmSTP1 facilitated the transport of glucose into host cells, promoting powdery mildew infection.