Filamentous pathogen effector functions: of pathogens, hosts and microbiomes

Abstract

Microorganisms play essential roles in almost every environment on earth. For instance, microbes decompose organic material, or establish symbiotic relationships that range from pathogenic to mutualistic. Symbiotic relationships have been particularly well studied for microbial plant pathogens and have emphasized the role of effectors; secreted molecules that support host colonization. Most effectors characterized thus far play roles in deregulation of host immunity. Arguably, however, pathogens not only deal with immune responses during host colonization, but also encounter other microbes including competitors, (myco)parasites and even potential co-operators. Thus, part of the effector catalog may target microbiome co-inhabitants rather than host physiology.

Specific Hypersensitive Response–Associated Recognition of New Apoplastic Effectors from Cladosporium fulvum in Wild Tomato

“…This raises the possibility that C. fulvum dedicates a significant proportion of its apoplastic secretome to functions associated with microbial antagonism, perhaps to outcompete other microbial organisms for nutrients and space in the apoplastic environment or to provide a form of self-defense (Rovenich et al 2014). Of course, it remains possible that the predicted similarities in tertiary structure do not extend to biological function.…”

Broadly Conserved Fungal Effector BEC1019 Suppresses Host Cell Death and Enhances Pathogen Virulence in Powdery Mildew of Barley (Hordeum vulgare L.) (Retracted)

“…The BEC1019 family, in which different members function in pathogenesis of plants versus animals, may provide an opportunity to discover broadly effective means of controlling fungal growth and infections important in both medicine and agriculture (Rovenich et al 2014).…”

RXLR Effector AVR2 Up-Regulates a Brassinosteroid-Responsive bHLH Transcription Factor to Suppress Immunity

“…The failure to completely attenuate cell death suppression by AVR2 could be due to the low silencing efficiency of the VIGS constructs. A common mode-of-action for phytopathogen effectors is to reduce or inhibit activity of their host targets (Rovenich et al, 2014). The enhanced P. infestans pathogenicity facilitated by AVR2 expression, in combination with its suppressive effect on PTI, does not support a model in which AVR2 inhibits the BR pathway.…”