Emerging Trends in Molecular Interactions between Plants and the Broad Host Range Fungal Pathogens Botrytis cinerea and Sclerotinia sclerotiorum

Abstract

Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum, the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi.

Reactive Oxygen Species Activity and Antioxidant Properties of Fusarium Infected Bananas

“…As such, apoptosis further strengthens the Fusarium infection as the fungus has the ability to easily colonize and spread (Morel and Dangl ; Mbengue et al. ).…”

“…Fusarium preys upon dead cells and is capable of absorbing and utilizing the nutrients from them. As such, apoptosis further strengthens the Fusarium infection as the fungus has the ability to easily colonize and spread (Morel and Dangl 1997;Mbengue et al 2016).…”

The genetics underlying natural variation of plant–plant interactions, a beloved but forgotten member of the family of biotic interactions

“…Direct physical contact between leaf tips is able to induce leaf hyponasty in A. thaliana (de Wit et al, 2012). Such mechanosensing is also connected to defense priming via JA (Chehab et al, 2012;Mbengue et al, 2016), pointing towards a strong connection between physiological responses of the focal plant to its neighbor plants and pathogens.…”

The polyphagous plant pathogenic fungusBotrytis cinereaencompasses host‐specialized and generalist populations

“…This may rely on functional variations into the diverse and sophisticated biochemical arsenal of B. cinerea. Indeed, this pathogen shows a large repertoire of secreted proteins, secondary metabolites and small interfering RNA (siRNA) that act as effectors in the interactions with its hosts (Reino et al, 2004;Siewers et al, 2005;Amselem et al, 2011;Weiberg et al, 2013;Mbengue et al, 2016;Valero-Jiménez et al, 2019). The possible role of the different fungal effectors in host specialization remains to be investigated, as well as the possible role of the host phytoalexins.…”