Autophagy is critical for plant defense against necrotrophic pathogens, which causes serious yield loss on crops. However, the post-translational regulatory mechanisms of autophagy pathway in plant resistance against necrotrophs remain poorly understood. In this study, we report that phosphorylation modification on ATG18a, a key regulator of autophagosome formation in Arabidopsis thaliana, constitutes a post-translation regulation of autophagy, which attenuates plant resistance against necrotrophic pathogens. We found that phosphorylation of ATG18a suppresses autophagosome formation and its subsequent delivery into the vacuole, which results in reduced autophagy activity and compromised plant resistance against Botrytis cinerea. In contrast, overexpression of ATG18a dephosphorylation-mimic form increases the accumulation of autophagosomes and complements the plant resistance of atg18a mutant against B. cinerea. Moreover, BAK1, a key regulator in plant resistance, was identified to physically interact with and phosphorylate ATG18a. Mutation of BAK1 blocks ATG18a phosphorylation at four of the five detected phosphorylation sites after B. cinerea infection and strongly activates autophagy, leading to enhanced resistance against B. cinerea. Collectively, the identification of functional phosphorylation sites on ATG18a and the corresponding kinase BAK1 unveiled how plant regulates autophagy during resistance against necrotrophic pathogens.

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Purpose To investigate causative variants in three Chinese families affected with familial exudative vitreoretinopathy (FEVR). Methods Three unrelated Chinese families were recruited in this study. The three probands and their family members experienced a comprehensive age-appropriate eye examination and genetic analysis. Luciferase assay was performed to evaluate impacts of variants on Norrin/β-catenin signaling activity. Results Here we report two novel NDP variants associated with FEVR in three families, including c.17T>C (p.Leu6Pro) in family 1 and c.58G>A (p.Gly20Arg) in family 2 and 3. These two variants were co-segregated with the disease phenotypes within each family. In addition, both variants resulted in compromised Norrin/β-catenin signaling activity. Conclusion Our study identified two FEVR-associated pathogenic variants in NDP, which expanded the variant spectrum and provided information for the genetic diagnosis of FEVR.