Understanding plant-fungal interactions is required to develop new disease control strategies. This understanding can be reached not only by studying antagonistic interactions of fungal pathogens that are detrimental to the fitness of their host but also by investigating mutualistic fungi that boost plant defense responses and support nutrient uptake by the host plant. Detrimental and beneficial interactions are not so far apart: sometimes a parasitic fungal species can become beneficial and vice versa. Whatever the nature of the interaction, the association between plants and fungi is a two-way process, yielding alterations in both partners.
As was highlighted in the Research Topic
How Can Secretomics Help Unravel the Secrets of Plant-Microbe Interactions, one fungal strategy to influence the plant-microbe interaction is via secretion of functional proteins. The identity of secreted fungal proteins can be efficiently predicted by bioinformatic analyses, provided, in silico tools are validated on experimental datasets. Wet-lab studies to confirm bioinformatic predictions have shown that microbes actively shape this interaction that is also dependent on environmental factors such as temperature, by secretion of peptidases, proteases and protease inhibitors, effector proteins, and the phytohormone salicylic acid. This communication between microbes and their host plant is mediated by exosomes and other extracellular vesicles (EVs), membrane-surrounded particles that are released by cells into their environment. The flow of information (i.e. delivered proteins or nucleic acids) is not only from the microbe to the plant but also in the opposite direction: some host plant EVs are taken up by pathogenic fungi, which may result in reducing fungal virulence.
Secretion of EVs by plants may be a plant defense mechanism that can be exploited for the development of novel efficient disease control strategies, such as plant exosome-mediated targeted delivery of antimicrobial peptides detrimental to the pathogen. Thus, knowledge about secretomes and other ways of communication of both fungi and plants is essential for the development of new disease control strategies.
In this Research Topic, we therefore aim to address the recent advances and challenges in the understanding of plant-fungal interactions, falling under, but not limited to:
- In vitro/in vivo secretomics
- Plant responses
- Proteases
- Bioinformatics and prediction tools
- Exosomes and extracellular vesicles
- Effectors
- Ecto- or endo-micorrhyzal associations
- Fungal pathogens of crops
- Fungal threat to natural ecosystems