Plant-Friendly Microorganisms as a Bio-Barrier Against Pathogens

Plants are threatened by diverse pathogen species living in complex communities that can enhance diseases or antagonize one another. The classic triangle in phytopathology requires the interaction of a susceptible host, a virulent pathogen, and an environment favorable for disease development. The plant microbiome affects both the host resistance and the plants' close surroundings. These microorganisms' communities inhabit the plant's rhizosphere (the roots' nearby habitat) or the phyllosphere (the plant's aboveground habitat) and comprise opportunistic pathogens and non-pathogenic members that may protect the plant from pathogens. They are formed by bacteria and fungi inhabiting the same ecological niche and cooperating or competing for the same plant resources. These endophytes and other members of the plant microbiome can now provide new ways of controlling plant diseases.

These intriguing communities and their relationships with the host plant have a potential benefit to modern agriculture, yet to be explored. Such research may provide a new eco-friendly toolkit to protect plants against harmful invasive microorganisms. To this end, we should gain a fundamental understanding of those microflorae’ composition, function in various biotic and abiotic stresses, and their host plant interactions.

The current research topic welcomes papers focusing on recent innovations and scientific progress in the relationships between plant-associated microorganisms and their implications for the plant’s defenses and immunity to diseases.

Potential topics include, but are not limited to:

1. Opportunistic phytopathogens and non-pathogenic microorganisms that may affect the disease’s outburst and severity.

2. Aspects of the biology of beneficial plant-associated microorganisms, including:
• genetic basis for their beneficial effects or development in association with the plant
• molecules involved in communication such as effectors and small-molecule signals
• plant hormones.

3. Applied methods to efficiently deliver and manipulate beneficial microorganisms.

Improving our knowledge of this research field will have practical benefits and is a vital opening stage for future follow-up studies.

Keywords: biological control, crop protection, endophytes, plant disease, plant health, plant host–pathogen interactions, plant microbiome, plant microflora, microbial interactions, microorganism communities

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.