Paenibacillus sp. strain UY79, isolated from a root nodule of Arachis villosa, displays a broad spectrum of antifungal activity

Costa, A.; Corallo, B.; Amarelle, V.; Stewart, S.; Pan, D.; Tiscornia, S.; Fabiano, E. R.

doi:10.1101/2021.03.26.437297

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bioRxiv · 10.1101/2021.03.26.437297

Paenibacillus sp. strain UY79, isolated from a root nodule of Arachis villosa, displays a broad spectrum of antifungal activity

Costa, A.·Corallo, B.·Amarelle, V.·Stewart, S.·Pan, D.·Tiscornia, S.·Fabiano, E. R.

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Abstract

A nodule-inhabiting Paenibacillus sp. strain (UY79) isolated from wild peanut (Arachis villosa) was screened for its antagonistic activity against diverse fungi and oomycetes (Botrytis cinerea, Fusarium verticillioides, Fusarium oxysporum, Fusarium graminearum, Fusarium semitectum, Macrophomina phaseolina, Phomopsis longicolla, Pythium ultimum, Phytophthora sojae, Rhizoctonia solani, Sclerotium rolfsii and Trichoderma atroviride). Results obtained show that Paenibacillus sp. UY79 was able to antagonize these fungi/oomycetes and that agar-diffusible metabolites and enzymes, as well as volatile compounds (different from HCN), participate in the antagonism exerted. We found that Paenibacillus sp. strain UY79 did not affect symbiotic association or growth promotion of alfalfa plants when co-inoculated with rhizobia. By whole genome sequence analysis, we determined that strain UY79 is a new species of Paenibacillus within the Paenibacillus polymyxa complex. Diverse genes putatively involved in biocontrol activity were identified in the UY79 genome. Moreover, according to genome mining and antibiosis assays, strain UY79 would have the capability to modulate the growth of bacteria commonly found in soil/plant communities. IMPORTANCEPhytopathogenic fungi and oomycetes are responsible for causing devastating losses in agricultural crops. Therefore, there is an enormous interest in the development of effective and complementary strategies that allow the control of the phytopathogens, reducing the input of agrochemicals in croplands. Discovery of new strains with expanded antifungal activities and with a broad spectrum of action is challenging and of great future impact. Diverse strains belonging to the P. polymyxa complex have been reported to be effective biocontrol agents. Results presented here show that the novel discovered strain of Paenibacillus sp. presents diverse traits involved in antagonistic activity against a broad spectrum of pathogens and would be a potential and valuable strain to be further assessed for the development of biofungicides.

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Costa, A., Corallo, B., Amarelle, V., Stewart, S., Pan, D., Tiscornia, S., Fabiano, E. R.. 2021-03-28. Paenibacillus sp. strain UY79, isolated from a root nodule of Arachis villosa, displays a broad spectrum of antifungal activity. https://doi.org/10.1101/2021.03.26.437297

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