2. Academic Validation
  3. SsATG8 and SsNBR1 mediated-autophagy is required for fungal development, proteasomal stress response and virulence in Sclerotinia sclerotiorum

SsATG8 and SsNBR1 mediated-autophagy is required for fungal development, proteasomal stress response and virulence in Sclerotinia sclerotiorum

  • Fungal Genet Biol. 2021 Dec;157:103632. doi: 10.1016/j.fgb.2021.103632.
Honghong Zhang 1,  Yurong Li 2,  Wenyu Lai 3,  Kun Huang 3,  Yaling Li 3,  Zonghua Wang 4,  Xiaofeng Chen 5,  Airong Wang 6
Affiliations

Affiliations

  • 1 Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China; Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China; Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA; Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA.
  • 2 Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA; Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA.
  • 3 Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China; Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.
  • 4 Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China; Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China; Institute of Oceanography, Minjiang University, Fuzhou, Fujian, China.
  • 5 Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China; Institute of Oceanography, Minjiang University, Fuzhou, Fujian, China. Electronic address: ChenXF@mju.edu.cn.
  • 6 Fujian University Key Laboratory for Plant-Microbe Interaction, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China; Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China. Electronic address: airongw@fafu.edu.cn.
PMID: 34710583 DOI: 10.1016/j.fgb.2021.103632
Abstract

Autophagy plays vital roles in the interaction between the necrotrophic Fungal pathogen Sclerotinia sclerotiorum and its hosts. However, so far, only little is known about the impacts of Autophagy machinery in S. sclerotiorum per se on the Fungal morphogenesis and pathogenesis. Here, through functional genomic approaches, we showed that SsATG8, one of the core components of the Autophagy machinery, and its interactor SsNBR1, an Autophagy cargo receptor, are important for vegetative growth, sclerotial formation, oxalic acid (OA) production, compound appressoria development, and virulence of S. sclerotiorum. Complementation assays with chimeric fusion constructs revealed that both LDS [AIM (ATG8 interacting motif) / LIR (LC3-interacting region) docking site] and UDS [UIM (ubiquitin-interacting motif) docking site] sites of the SsATG8 are required for its functions in Autophagy and pathogenesis. Importantly, ΔSsatg8 and ΔSsnbr1 mutants showed enhanced sensitivity to the exogenous treatment with the Proteasome inhibitors bortezomib and carfilzomib, and ΔSsnbr1 mutant had decreased expression of SsATG8 under the proteasomal stress conditions, suggesting that a cross-talk exists between ubiquitin-proteasome and selective Autophagy pathways, which enables downstream protein degradation to proceed properly during diverse biological processes. Collectively, our data indicate that SsATG8- and SsNBR1-mediated Autophagy is crucial for S. sclerotiorum development, proteasomal stress response and virulence.

Keywords

ATG8; Autophagy; NBR1; Sclerotinia sclerotiorum; Virulence.

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