Genetic analysis reveals unprecedented diversity of a globally-important plant pathogenic genus

Andrea R. Garfinkel,Katie P. Coats,Gary A. Chastagner,Don L. Sherry

doi:10.1038/s41598-019-43165-y

Andrea R. Garfinkel, Katie P. Coats + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-43165-y

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Abstract

Genus Botrytis contains approximately 35 species, many of which are economically-important and globally-distributed plant pathogens which collectively infect over 1,400 plant species. Recent efforts to genetically characterize genus Botrytis have revealed new species on diverse host crops around the world. In this study, surveys and subsequent genetic analysis of the glyceraldehyde-3-phosate dehydrogenase (G3PDH), heat-shock protein 60 (HSP60), DNA-dependent RNA polymerase subunit II (RPB2), and necrosis and ethylene-inducing proteins 1 and 2 (NEP1 and NEP2) genes indicated that Botrytis isolates collected from peony fields in the United States contained more species diversity than ever before reported on a single host, including up to 10 potentially novel species. Together, up to 16 different phylogenetic species were found in association with peonies in the Pacific Northwest, which is over a third of the total number of species that are currently named. Furthermore, species were found on peonies in Alaska that have been described on other host plants in different parts of the world, indicating a wider geographic and host distribution than previously thought. Lastly, some isolates found on peony share sequence similarity with unnamed species found living as endophytes in weedy hosts, suggesting that the isolates found on peony have flexible lifestyles as recently discovered in the genus. Selected pathogenicity, growth, and morphological characteristics of the putatively new Botrytis species were also assessed to provide a basis for future formal description of the isolates as new species.

Highlights

Fungi in genus Botrytis are economically-important agricultural plant pathogens that collectively infect nearly 600 diverse plant genera comprising 170 monocotyledonous and dicotyledonous plant families[1]
New species descriptions are supported by phylogenetic analysis of 5 genes most widely used and accepted for species delineation in Botrytis: glyceraldehyde-3-phosate dehydrogenase (G3PDH), heat-shock protein 60 (HSP60), DNA-dependent RNA polymerase subunit II (RPB2), and necrosis and ethylene-inducing proteins 1 and 2 (NEP1 and NEP2)[6,20,24,25]
Botrytis grey mould of peonies has been reported to be caused by four species of Botrytis: B. cinerea, described above; B. paeoniae, a putatively host-specific pathogen of peonies present in most areas where peonies are grown[1,26,27,28]; B. pseudocinerea, a recently described so-called “cryptic” species of Botrytis that is only distinguishable from B. cinerea through genetic analysis and fenhexamid fungicide sensitivity[19,27,29]; and B. euroamericana, a fungus found on both peony and grape that was reported from Alaska and Italy, respectively[13]

Summary

Introduction

Fungi in genus Botrytis are economically-important agricultural plant pathogens that collectively infect nearly 600 diverse plant genera comprising 170 monocotyledonous and dicotyledonous plant families[1]. Many of these species putatively infect only a restricted range of host plant species, the polyphagous B. cinerea alone has been documented to cause disease on 586 genera[1]. This species can be found infecting plants in remote locations from Hawaii[2] to the Canary Islands[3], and has even been recorded from environmental samples in Antarctica[4], making the influence of this pathogen truly global. We report phylogenetic diversity in genus Botrytis that is yet unprecedented in other surveys that have been conducted throughout the world on other host crop species

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