Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli Studi di Milano, 20133, Milan, Italy.
Institute of Sciences of Food Production, Italian National Research Council, Via Celoria 2, 20133, Milan, Italy.
Microbiol Res. 2017 May;198:16-26. doi: 10.1016/j.micres.2017.02.001. Epub 2017 Feb 10.
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.
开发新的可持续植物病害防治策略对于保障粮食安全、减少农业对环境的影响非常重要。新生物防治剂的研究是一个漫长而艰难的过程，涉及几个步骤，从可能的候选物的鉴定开始，例如具有抗生素活性的候选物，最后是在田间进行大规模试验。在这项研究中，通过 16S rRNA 和 rpoB 基因序列分析，将一株新型潜在生防菌 R16 鉴定为类芽孢杆菌（Paenibacillus pasadenensis），评估了其对三种重要植物病原真菌（灰葡萄孢、串珠镰刀菌和葡萄座腔菌）的促生作用和抑菌作用。生化分析表明，该菌具有 ACC 脱氨酶活性和 IAA 产生能力，但不具有产铁载体和溶磷能力。进一步的生化分析表明，该菌具有内生生活方式和产几丁质酶活性。体外拮抗试验表明，R16 菌株对灰葡萄孢具有拮抗作用，无论是在双培养物中还是通过挥发性物质，都能抑制其菌丝生长，其中挥发性物质主要由法呢醇组成，并能抑制孢子萌发。该菌对葡萄座腔菌也具有良好的拮抗潜力，但对串珠镰刀菌没有作用。此外，体内试验证实 R16 菌株能降低灰葡萄孢侵染浆果的发病率。这些结果首次证明，类芽孢杆菌 R16 菌株是一种潜在的植物促生菌，对植物病原菌具有抑菌作用。需要进一步的研究来探讨该菌株作为生物防治剂的应用潜力。
