title: Competition assays revealed Paenibacillus pasadenensis strain R16 as a novel antifungal agent.
abstract: The development of new sustainable containment strategies of plant diseases is very important to guarantee food security while reducing the environmental impact of agriculture. Research of new biocontrol agents is a long and difficult process that involves several steps that start from the identification of possible candidates which, for example, show antibiotic activities, and ends with in field, large scale trials. In this study, the plant growth promoting potential and antifungal effect exerted by a novel, putative candidate biocontrol agent, strain R16, identified as Paenibacillus pasadenensis by sequence analysis of 16S rRNA and rpoB genes, against three important plant pathogenic fungi (Botrytis cinerea, Fusarium verticillioides, and Phomopsis viticola), were assessed. Biochemical assays to determine plant growth promoting potential gave negative results for siderophore production and phosphate solubilization, and positive results for ACC-deamination and IAA production. Further biochemical assays for endophytic lifestyle and antifungal activity gave positive results for catalase and chitinase activity, respectively. In vitro antagonism assays showed that strain R16 is effective against B. cinerea, reducing mycelial growth both in dual-culture and through volatile substances, characterized to be mostly composed by farnesol, and inhibiting conidia germination. Good antagonistic potential was also observed in vitro towards P. viticola, but not towards F. verticillioides. Moreover, in vivo assays confirmed the strain R16 activity reduced the infection rate on B. cinerea-inoculated berries. The obtained results firstly proved that P. pasadenesis strain R16 is a putative plant growth promoter and effective against phytopathogenic fungi. Further studies will be needed to investigate the possible application of this strain as a biocontrol agent.
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli Studi di Milano, 20133, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Passera
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli Studi di Milano, 20133, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Venturini
authors.affiliation: Institute of Sciences of Food Production, Italian National Research Council, Via Celoria 2, 20133, Milan, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Battelli
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli Studi di Milano, 20133, Milan, Italy. Electronic address: paola.casati@unimi.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Casati
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli Studi di Milano, 20133, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Penaca
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli Studi di Milano, 20133, Milan, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Quaglino
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli Studi di Milano, 20133, Milan, Italy.
authors.forename: Piero Attilio
authors.initials: PA
authors.lastname: Bianco
mesh_terms: D000898:Antibiosis; D000935:Antifungal Agents / Q000378:metabolism; D001203:Ascomycota / Q000254:growth & development*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D005204:Farnesol / Q000378:metabolism; D056507:Paenibacillus / Q000254:growth & development / Q000502:physiology*; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control; D010937:Plant Growth Regulators / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000935:Antifungal Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D010937:Plant Growth Regulators; D012336:RNA, Ribosomal, 16S; D005204:Farnesol; D012321:DNA-Directed RNA Polymerases; C105078:RNA polymerase beta subunit
keywords: Antifungal activity; Botrytis cinerea; Farnesol; Grape; Paenibacillus pasadenensis