Rhizobium anhuiense as the predominant microsymbionts of Lathyrus maritimus along the Shandong Peninsula seashore line

Abstract

a b s t r a c tBeach pea [Lathyrus maritimus Bigelow, or Lathyrus japonicus subsp. maritimus (L.) P.W. Ball] is a wild legume distributed on the seashore line, and the rhizobia nodulating with this plant have been reported only rarely. In order to reveal the diversity of beach pea rhizobia on the seashore line of Shandong Peninsula, China, a total of 124 bacterial strains were isolated from the root nodules of beach pea plants collected from five sites. All the isolates were divided into five recA types after screening by recA gene sequence analysis and they consisted of Rhizobium anhuiense covering 122 symbiotic isolates in three recA types, as well as two single isolates Rhizobium sp. and Rhizobium lusitanum representing distinct recA types. The recA genotype III of R. anhuiense (103 isolates) represented by strain YIC11270 was dominant at all five sampling sites. Identical symbiotic genes (nodC and nifH) were detected in the three recA genotypes of R. anhuiense isolates that were closely related to those of the pea and faba rhizobia. This study clarified that R. anhuiense was the main symbiont for beach pea rhizobia on the seashore line of Shandong Peninsula. The low level genetic diversity of beach pea rhizobia revealed by both MLSA and the symbiotic genes might be related to the strong selection pressure produced by the saline-alkaline environment and the host plants.

Long-term monoculture reduces the symbiotic rhizobial biodiversity of peanut

“…In the present study, the failure to amplify both nodC and nifH from B. huanghuaihaiense 65,027 and 65,047 is consistent with their failure in nodulation; thus, they might be nonsymbiotic endophytes for peanut, similar to the other nonsymbiotic bacteria isolated from Lathyrus maritimus, Caragana jubata and Oxytropis ochrocephala [21,46]. However, the reason for the failure of amplification of nodC from B. guangdongense 61,102, B. yuanmingense 65,010, Bradyrhizobium sp.…”

“…All the recA sequences obtained in this study were aligned using Clustal W software [48], and then the haplotype was determined using DNASP v5 [25]. Since recA sequence analysis has been used as an effective marker to select representative strains of both slow-and fast-growing rhizobia [20,21,48], a representative sequence and the corresponding isolate for each recA haplotype were randomly selected for further study.…”

Biodiversity and Geographic Distribution of Rhizobia Nodulating With Vigna minima

“…Thus, recA is superior to other markers and could be widely used in defining rhizobial haplotypes. The definition of 41 haplotypes in Bradyrhizobium based on recA sequences among these isolates primitively evidenced their great genetic diversity and further confirmed the recA sequence analysis as an effective screening method to group the rhizobial isolates, identify the genus, and select the representative strains ( Supplementary Tables 1 , 2 ) for further phylogenetic study ( Li et al, 2016a , b ; Shao et al, 2020 ; Zhang et al, 2020 ). In MLSA of the five housekeeping genes ( glnII , dnaK , gyrB , rpoB , and recA ), the identification of 18 Bradyrhizobium genospecies among the isolates revealed that V. minima only nodulated with Bradyrhizobium in the studied sites that is consistent with the cultured Vigna species ( Yang et al, 2008 ; Han et al, 2009 ; Hakim et al, 2018 ; Ibny et al, 2019 ).…”

“…Multilocus sequence analysis (MLSA) was conducted by combining the sequences of five housekeeping genes ( dnaK , glnII , gyrB , recA , and rpoB ), and the sequence similarities between representative and reference strains were calculated using MEGA 7.0 ( Kumar et al, 2016 ). A threshold of 97% sequence similarity was used to define genospecies as suggested previously ( Cao et al, 2014 ; Li et al, 2016b ).…”

The genetic diversity of microsymbionts from Thermopsis lanceolata growing in Mongolia

“…9 99,9 99,9 99,9 99,9 98,3 98,9 98,9 98 9 96,9 88,9 87,9 87,9 87,9 P. endophyticum [25]. Бактерии R. anhuiense являются также микросимбионтами чины японской Lathyrus japonicus [26]. Было показано, что для L. japonicus ха-рактерна очень высокая способность к азотфиксации, особенно в условиях низких температур арктического и субарктического регионов, где данное растение рассматривается в качестве перспективной кормовой культуры [27].…”