Tomada Selena, Puopolo Gerardo, Perazzolli Michele, Musetti Rita, Loi Nazia, Pertot Ilaria
Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund MachSan Michele all'Adige, Italy; Agricultural Science and Biotechnology Program, Department of Agricultural, Food, Environmental, and Animal Sciences, University of UdineUdine, Italy.
Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach San Michele all'Adige, Italy.
Front Microbiol. 2016 Jul 26;7:1136. doi: 10.3389/fmicb.2016.01136. eCollection 2016.
Bacterial cells can display different types of motility, due to the presence of external appendages such as flagella and type IV pili. To date, little information on the mechanisms involved in the motility of the Lysobacter species has been available. Recently, L. capsici AZ78, a biocontrol agent of phytopathogenic oomycetes, showed the ability to move on jellified pea broth. Pea broth medium improved also the biocontrol activity of L. capsici AZ78 against Plasmopara viticola under greenhouse conditions. Noteworthy, the quantity of pea residues remaining on grapevine leaves fostered cell motility in L. capsici AZ78. Based on these results, this unusual motility related to the composition of the growth medium was investigated in bacterial strains belonging to several Lysobacter species. The six L. capsici strains tested developed dendrite-like colonies when grown on jellified pea broth, while the development of dendrite-like colonies was not recorded in the media commonly used in motility assays. To determine the presence of genes responsible for biogenesis of the flagellum and type IV pili, the genome of L. capsici AZ78 was mined. Genes encoding structural components and regulatory factors of type IV pili were upregulated in L. capsici AZ78 cells grown on the above-mentioned medium, as compared with the other tested media. These results provide new insight into the motility mechanism of L. capsici members and the role of type IV pili and pea compounds on the epiphytic fitness and biocontrol features of L. capsici AZ78.
由于存在鞭毛和IV型菌毛等外部附属物，细菌细胞可表现出不同类型的运动性。迄今为止，关于溶杆菌属物种运动性所涉及的机制的信息很少。最近，植物致病卵菌的生防菌辣椒溶杆菌AZ78显示出在凝胶化豌豆肉汤上移动的能力。豌豆肉汤培养基还提高了辣椒溶杆菌AZ78在温室条件下对葡萄霜霉病菌的生防活性。值得注意的是，残留在葡萄叶片上的豌豆残留物促进了辣椒溶杆菌AZ78中的细胞运动性。基于这些结果，在属于几种溶杆菌属物种的细菌菌株中研究了这种与生长培养基组成相关的异常运动性。测试的6株辣椒溶杆菌菌株在凝胶化豌豆肉汤上生长时形成了树枝状菌落，而在运动性测定中常用的培养基中未记录到树枝状菌落的形成。为了确定负责鞭毛和IV型菌毛生物合成的基因的存在，对辣椒溶杆菌AZ78的基因组进行了挖掘。与其他测试培养基相比，在上述培养基上生长的辣椒溶杆菌AZ78细胞中，编码IV型菌毛结构成分和调节因子的基因上调。这些结果为辣椒溶杆菌成员的运动机制以及IV型菌毛和豌豆化合物对辣椒溶杆菌AZ78的附生适应性和生防特性的作用提供了新的见解。
