The tomato Arp2/3 complex is required for resistance to the powdery mildew fungus Oidium neolycopersici. (17th July 2019)

• Record Type: Journal Article
• Authors: Sun, Guangzheng; Feng, Chanjing; Guo, Jia; Zhang, Ancheng; Xu, Yuanliu; Wang, Yang; Day, Brad; Ma, Qing
• Is Part Of: Plant, cell and environment. Volume 42:Number 9(2019)
• Page Start: 2664
• Page End: 2680
• Publication Date: 2019-07-17
• Subjects: actin cytoskeleton -- Arp2/3 complex -- ARPC3 -- powdery mildew -- resistance -- Solanum habrochaites; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.13569
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: The actin‐related protein 2/3 complex (Arp2/3 complex), a key regulator of actin cytoskeletal dynamics, has been linked to multiple cellular processes, including those associated with response to stress. Herein, the Solanum habrochaites ARPC3 gene, encoding a subunit protein of the Arp2/3 complex, was identified and characterized. ShARPC3 encodes a 174‐amino acid protein possessing a conserved P21‐Arc domain. Silencing of ShARPC3 resulted in enhanced susceptibility to the powdery mildew pathogen Oidium neolycopersici ( On ‐Lz), demonstrating a role for ShARPC3 in defence signalling. Interestingly, a loss of ShARPC3 coincided with enhanced susceptibility to On ‐Lz, a process that we hypothesize is the result of a block in the activity of SA‐mediated defence signalling. Conversely, overexpression of ShARPC3 in Arabidopsis thaliana, followed by inoculation with On ‐Lz, showed enhanced resistance, including the rapid induction of hypersensitive cell death and the generation of reactive oxygen. Heterologous expression of ShARPC3 in the arc18 mutant of Saccharomyces cerevisiae (i.e., ∆arc18 ) resulted in complementation of stress‐induced phenotypes, including high‐temperature tolerance. Taken together, these data support a role for ShARPC3 in tomato through positive regulation of plant immunity in response to O . neolycopersici pathogenesis. Abstract : The current study illuminates our understanding of the role of the Arp2/3 complex during the activation and regulation of plant immunity. Using the model plantpathogen system tomato‐powdery mildew, we describe a function for ARPC3 during infection and defense signaling. Following pathogen infection, we observed that ARPC3 was significantly up‐regulated during infection with an incompatible pathogen. From this observation, we investigated the broader for actin and the ARP2/3 regulatory node in mediating the connectivity between immune signaling and broader cell response signaling processes associated with stress and development. Indeed, overexpression of tomato ARPC3 in Arabidopsis thaliana, followed by inoculation with the powdery mildew pathogen led to enhanced pathogen resistance, including the rapid induction of hypersensitive cell death and the generation of reactive oxygen. Similarly, heterologous expression of tomato ARPC3 in the arc18 mutant of Saccharomyces cerevisiae resulted in complementation of stress‐induced phenotypes, including high‐temperature tolerance. Taken together, these data support a role for ARPC3 in the positive regulation of plant immunity in response to powdery mildew pathogenesis.