ATG8h与ATG8i是拟南芥基因组编码的9个ATG8蛋白中一个独特亚群。与其它ATG8成员不同, ATG8h和ATG8i的C末端天然携带甘氨酸残基, 无需ATG4i切割即可完成脂化修饰。前期研究发现, 网格蛋白轻链2 (clathrin light chain 2, CLC2)通过与ATG8h/ATG8i互作参与自噬过程; 利用CRISPR/Cas9技术双敲除ATG8h和ATG8i会损害自噬功能, 从而增强对活体营养型真菌病原菌的抗性。该研究采用功能获得性策略进一步探究ATG8i在抗病中的作用。结果表明, 过表达ATG8i能增强对活体营养型细菌和真菌病原菌的抗性, 但会降低对死体营养型真菌分泌的毒素的耐受性。这种抗性增强与病原菌侵染诱导的胼胝质沉积和H2O2水平升高相关。

ATG8h and ATG8i are an unique sub-group of the nine ATG8 proteins encoded in Arabidopsis genome that do not need ATG4 protease for cleavage to expose their C-terminal Gly residue for lipidation and subsequent recruitment to the autophagosomal membranes. We previously showed that clathrin light chain 2 (CLC2) participates autophagy through interacting ATG8h and ATG8i and knocking out ATG8h and ATG8i simultaneously compromised autophagy, and as a result, enhanced the resistance to a biotrophic fungal pathogen. In this study, we further investigate the roles of ATG8i in disease resistance by over-expressing ATG8i. Our results showed that over-expression of ATG8i enhanced the resistance to biotrophic bacterial and fungal pathogens but compromised the resistance to a toxin secreted from a necrotropic fungal pathogen. The enhanced resistance to the biotrophic pathogens were correlated with the elevated levels of both callos deposition and H2O2 induced by Golovinomyces cichoracearum infection.