Dataset Information

Multiple Genes of Symbiotic Plasmid and Chromosome in Type II Peanut Bradyrhizobium Strains Corresponding to the Incompatible Symbiosis With Vigna radiata.

ABSTRACT: Rhizobia are capable of establishing compatible symbiosis with their hosts of origin and plants in the cross-nodulation group that the hosts of origin belonged to. However, different from the normal peanut Bradyrhizobium (Type I strains), the Type II strains showed incompatible symbiosis with Vigna radiata. Here, we employed transposon mutagenesis to identify the genetic loci related to this incompatibility in Type II strain CCBAU 53363. As results, seven Tn5 transposon insertion mutants resulted in an increase in nodule number on V. radiata. By sequencing analysis of the sequence flanking Tn5 insertion, six mutants were located in the chromosome of CCBAU 53363, respectively encoding acyltransferase (L265) and hypothetical protein (L615)-unique to CCBAU 53363, two hypothetical proteins (L4 and L82), tripartite tricarboxylate transporter substrate binding protein (L373), and sulfur oxidation c-type cytochrome SoxA (L646), while one mutant was in symbiotic plasmid encoding alanine dehydrogenase (L147). Significant differences were observed in L147 gene sequences and the deduced protein 3D structures between the Type II (in symbiotic plasmid) and Type I strains (in chromosome). Conversely, strains in both types shared high homologies in the chromosome genes L373 and L646 and in their protein 3D structures. These data indicated that the symbiotic plasmid gene in Type II strains might have directly affected their symbiosis incompatibility, whereas the chromosome genes might be indirectly involved in this process by regulating the plasmid symbiosis genes. The seven genes may initially explain the complication associated with symbiotic incompatibility.

SUBMITTER: Wu Y

PROVIDER: S-EPMC7324677 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Multiple Genes of Symbiotic Plasmid and Chromosome in Type II Peanut Bradyrhizobium Strains Corresponding to the Incompatible Symbiosis With Vigna radiata.

Wu Yue Y Li Yong Hua YH Shang Jiao Ying JY Wang En Tao ET Chen La Huo Bin B Sui Xin Hua XH Tian Chang Fu CF Chen Wen Feng WF Chen Wen Xin WX

Frontiers in microbiology 20200623

Rhizobia are capable of establishing compatible symbiosis with their hosts of origin and plants in the cross-nodulation group that the hosts of origin belonged to. However, different from the normal peanut Bradyrhizobium (Type I strains), the Type II strains showed incompatible symbiosis with Vigna radiata. Here, we employed transposon mutagenesis to identify the genetic loci related to this incompatibility in Type II strain CCBAU 53363. As results, seven Tn5 transposon inse ...[more]

PMID: 32655513

Similar Datasets

Project description:Bradyrhizobium guangxiense CCBAU53363 efficiently nodulates peanut but exhibits incompatible interaction with mung bean. By comparing the common nod region with those of other peanut bradyrhizobia efficiently nodulating these two hosts, distinctive characteristics with a single nodD isoform (nodD1) and a truncated nolA were identified. However, the regulatory roles of NodD1 and NolA and their coordination in legume-bradyrhizobial interactions remain largely unknown in terms of explaining the contrasting symbiotic compatibility. Here, we report that nolA was important for CCBAU53363 symbiosis with peanut but restricted nodulation on mung bean, while nodD1 was dispensable for CCBAU53363 symbiosis with peanut but essential for nodulation on mung bean. Moreover, nolA exerted a cumulative contribution with nodD1 to efficient symbiosis with peanut. Additionally, mutants lacking nolA delayed nodulation on peanut, and both nolA and nodD1 were required for competitive nodule colonization. It is noteworth that most of the nodulation genes and type III secretion system (T3SS)-related genes were significantly downregulated in a strain 53ΔnodD1nolA mutant compared to wild-type strain CCBAU53363, and the downregulated nodulation genes also had a greater impact than T3SS-related genes on the symbiotic defect of 53ΔnodD1nolA on peanut, which was supported by a more severe symbiotic defect induced by 53ΔnodC than that with the 53ΔnodD1nopP, 53ΔnodD1rhcJ, and 53ΔnodD1ttsI mutants. NolA did not regulate nod gene expression but did regulate the T3SS effector gene nopP in an indirect way. Meanwhile, nolA, nodW, and some T3SS-related genes besides nopP were also demonstrated as new "repressors" that seriously impaired CCBAU53363 symbiosis with mung bean. Taken together, the roles and essentiality of nolA and nodD1 in modulating symbiotic compatibility are sophisticated and host dependent. IMPORTANCE The main findings of this study were that we clarified that the roles and essentiality of nodD1 and nolA are host dependent. Importantly, for the first time, NolA was found to positively regulate T3SS effector gene nopP to mediate incompatibility on mung bean. Additionally, NolA does not regulate nod genes, which are activated by NodD1. nolA exerts a cumulative effect with nodD1 on CCBAU53363 symbiosis with peanut. These findings shed new light on our understanding of coordinated regulation of NodD1 and NolA in peanut bradyrhizobia with different hosts.

Project description:Bradyrhizobium sp. DOA9 isolated from the legume Aeschynomene americana exhibited a broad host range and divergent nodulation (nod) genes compared with other members of the Bradyrhizobiaceae. Genome analysis of DOA9 revealed that its genome comprised a single chromosome of 7.1 Mbp and a plasmid of 0.7 Mbp. The chromosome showed highest similarity with that of the nod gene-harboring soybean symbiont B. japonicum USDA110, whereas the plasmid showed highest similarity with pBBta01 of the nod gene-lacking photosynthetic strain BTAi1, which nodulates Aeschynomene species. Unlike in other bradyrhizobia, the plasmid of DOA9 encodes genes related to symbiotic functions including nodulation, nitrogen fixation, and type III/IV protein secretion systems. The plasmid has also a lower GC content (60.1%) than the chromosome (64.4%). These features suggest that the plasmid could be the origin of the symbiosis island that is found in the genome of other bradyrhizobia. The nod genes of DOA9 exhibited low similarity with those of other strains. The nif gene cluster of DOA9 showed greatest similarity to those of photosynthetic bradyrhizobia. The type III/IV protein secretion systems of DOA9 are similar to those of nod gene-harboring B. elkanii and photosynthetic BTAi1. The DOA9 genome exhibited intermediate characteristics between nod gene-harboring bradyrhizobia and nod gene-lacking photosynthetic bradyrhizobia, thus providing the evidence for the evolution of the Bradyrhizobiaceae during ecological adaptation. Bradyrhizobium sp. DOA9 isolated from the legume Aeschynomene americana exhibited a broad host range and divergent nodulation (nod) genes compared with other members of the Bradyrhizobiaceae. Genome analysis of DOA9 revealed that its genome comprised a single chromosome of 7.1 Mbp and a plasmid of 0.7 Mbp. The chromosome showed highest similarity with that of the nod gene-harboring soybean symbiont B. japonicum USDA110, whereas the plasmid showed highest similarity with pBBta01 of the nod gene-lacking photosynthetic strain BTAi1, which nodulates Aeschynomene species. Unlike in other bradyrhizobia, the plasmid of DOA9 encodes genes related to symbiotic functions including nodulation, nitrogen fixation, and type III/IV protein secretion systems. The plasmid has also a lower GC content (60.1%) than the chromosome (64.4%). These features suggest that the plasmid could be the origin of the symbiosis island that is found in the genome of other bradyrhizobia. The nod genes of DOA9 exhibited low similarity with those of other strains. The nif gene cluster of DOA9 showed greatest similarity to those of photosynthetic bradyrhizobia. The type III/IV protein secretion systems of DOA9 are similar to those of nod gene-harboring B. elkanii and photosynthetic BTAi1. The DOA9 genome exhibited intermediate characteristics between nod gene-harboring bradyrhizobia and nod gene-lacking photosynthetic bradyrhizobia, thus providing the evidence for the evolution of the Bradyrhizobiaceae during ecological adaptation.

Dataset Information

Multiple Genes of Symbiotic Plasmid and Chromosome in Type II Peanut Bradyrhizobium Strains Corresponding to the Incompatible Symbiosis With Vigna radiata.

Publications

Multiple Genes of Symbiotic Plasmid and Chromosome in Type II Peanut <i>Bradyrhizobium</i> Strains Corresponding to the Incompatible Symbiosis With <i>Vigna radiata</i>.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets