Bacterial communities associated with food-grade winter pea cultivars grown in Pacific Northwest soils. Part two

In this study we evaluated bacterial root and nodule microbiomes associated with three new food-grade WP cultivars and one more genetically distant WP genotype grown in three diverse locations across Washington state (WA) with the goal to assess the WP symbiotic potential, survey native rhizobia capable of establishing N-fixing symbioses with these plants and identify non-rhizobial nodule residents with the potential to be part of bacteria-legume symbiotic interaction. Our data indicate that a diverse population of native rhizobia can colonize WP roots cultivated in WA soils. However, a substantially smaller subset of these bacteria can colonize WP nodules. Interestingly, three rhizobial Amplicon Sequence Variants ASVs were dominant nodule residents in all tested locations regardless of the significant variation in soil microbiome diversity and structure between locations. These ASVs had relatively low abundance in the soils, indicating their strong attraction to host-plant roots and high competitiveness for nodulation. Our data indicate that Pseudomonas was apparently enriched in the summer-collected nodules compared to roots. However, an in-depth study of legume root and nodule microbiome is required to better understand Rhizobium-legume-Pseudomonas symbiotic interaction.

在本项研究中，我们评估了与华盛顿州（WA）三个新的食品级WP栽培品种以及一个遗传距离较远的WP基因型相关的细菌根瘤微生物组，旨在评估WP共生潜力，调查能够与这些植物建立固氮共生关系的原位根瘤菌，并识别具有成为细菌-豆科植物共生相互作用一部分潜力的非根瘤菌根瘤居民。我们的数据表明，多种原生根瘤菌能够定殖于在华盛顿州土壤中培育的WP根。然而，这些细菌中只有一小部分能够定殖于WP根瘤。有趣的是，三个根瘤菌扩增子序列变异体（Amplicon Sequence Variants，ASVs）在所有测试地点均为优势根瘤居民，尽管各地点的土壤微生物群落多样性和结构存在显著差异。这些ASVs在土壤中的丰度相对较低，表明它们对宿主植物根的强烈吸引力以及在高结瘤竞争力方面。我们的数据显示，与根相比，夏季收集的根瘤中铜绿假单胞菌（Pseudomonas）似乎富集。然而，为了更深入地理解根瘤菌-豆科植物-铜绿假单胞菌共生作用，对豆科植物根瘤和根的微生物组进行深入研究是必要的。