Biofilm formation is important for establishing plants-microbe associations. The role of calcium on biofilm formation has been studied in many bacteria except rhizobia. In this study, we investigated the role of calcium for biofilm formation in Azorhizobium caulindans, which forms nodules in the stem and root of its host plant Sesbania rostrata. We found that calcium is essential for A. caulindans biofilm formation, in addition to the presence of extracellular matrix components, eDNA and proteins. Also, calcium-mediated biofilm formation was tested with chemotaxis, motility, cyclic di-GMP synthesis, and quorum sensing mutants. Finally, calcium was found to promote S. rostrata root colonization of A. caulinodans. In total, these results show that calcium is essential for A. caulindans biofilm formation, and it affects the interaction between A. caulinodans and host plant.

生物膜的形成对于建立植物与微生物的联系很重要。除根瘤菌外，许多细菌还研究了钙对生物膜形成的作用。在这项研究中，我们调查了钙在生物膜形成中的作用固氮假单胞菌在其寄主植物的茎和根中形成结节 芝麻树。我们发现钙对于花椰菜生物膜的形成，以及细胞外基质成分，eDNA和蛋白质的存在。此外，还通过趋化性，运动性，循环双GMP合成和群体感应突变体测试了钙介导的生物膜形成。最后，发现钙可以促进罗氏葡萄球菌 的根定植 花椰菜。总的来说，这些结果表明钙对于花椰菜 生物膜的形成，并影响之间的相互作用 花椰菜 和寄主植物。