Proteinaceous necrotrophic effectors in fungal virulence

Abstract

Abstract. The host-pathogen interface can be considered as a biological battlefront. Molecules produced by both the pathogen and the host are critical factors determining the outcome of the interaction. Recent studies have revealed that an increasing number of necrotrophic fungal pathogens produce small proteinaceous effectors that are able to function as virulence factors. These molecules can cause tissue death in host plants that possess dominant sensitivity genes, leading to subsequent pathogen colonisation. Such effectors are only found in necrotrophic fungi, yet their roles in virulence are poorly understood. However, several recent key studies of necrotrophic effectors from two wheat (Triticum aestivum L.) pathogens, Pyrenophora tritici-repentis (Died.) Drechs. and Stagonospora nodorum (Berk.) Castell. & Germano, have shed light upon how these effector proteins serve to disable the host from the inside out.

Roles and delivery mechanisms of fungal effectors during infection development: common threads and new directions

“…We will also attempt to group fungal effectors together by mode of action; while effectors diverge in sequence, it would appear that some exert similar effects on their hosts. While we take a special interest in the hemi-biotrophic and biotrophic plant pathogens in this review, we will also draw from research into delivery mechanisms and modes of action of mammalian pathogen effectors, and effectors from necrotrophic fungi (for outstanding reviews, see [6,7], respectively). Impressively, since 2011 at least 18 research articles have been published on fungal effectors in plants; we will draw from these and a cohort of other related studies in the following review, and apologize in advance for those we were unable to include due to space constraints.…”

Sensitivity to three Parastagonospora nodorum necrotrophic effectors in current Australian wheat cultivars and the presence of further fungal effectors

“…The fungus is responsible for yield losses estimated at AU $108 million per year in Australia (Murray and Brennan 2009;Oliver et al 2012). SNB is quantitatively governed by the interaction of fungal necrotrophic effectors (NEs) with the products of host dominant sensitivity genes (Faris et al 2010;Tan et al 2010). A compatible interaction results in host tissue necrosis, which promotes infection by the pathogen.…”

Extracellular protease activity and glucose production in isolates of net blotch pathogens differing in virulence

“…In general, more virulent isolates may establish themselves faster by producing certain types of enzymes and toxins for attachment to the cell wall (Tan et al, 2010;Ismail et al, 2014). On the other hand, the less virulent isolates might take a longer time to produce toxins and pathogen-related metabolites.…”