da Silva Thaíse Rosa, Rodrigues Ruth Terezinha, Jovino Raphael Silva, Carvalho Jackson Rafael de Sá, Leite Jakson, Hoffman Andreas, Fischer Doreen, Ribeiro Paula Rose de Almeida, Rouws Luc Felicianus Marie, Radl Viviane, Fernandes-Júnior Paulo Ivan
Colegiado de Farmácia, Universidade Federal do Vale do São Francisco (Univasf), Petrolina, PE 56304-205, Brazil.
Universidade Estadual da Paraíba (UEPB), Campina Grande, PB 58429-500, Brazil.
J Appl Microbiol. 2023 Jan 23;134(1). doi: 10.1093/jambio/lxac013.
To isolate and characterize non-rhizobial nodule-associated bacteria (NAB) from cowpea root-nodules regarding their performance of plant-growth-promoting mechanisms and their ability to enhance cowpea growth and symbiosis when co-inoculated with bradyrhizobia.
Sixteen NAB were isolated, identified, and in vitro evaluated for plant growth promotion traits. The ability to promote cowpea growth was analyzed when co-inoculated with Bradyrhizobium pachyrhizi BR 3262 in sterile and non-sterile substrates. The 16S rRNA gene sequences analysis revealed that NAB belonged to the genera Chryseobacterium (4), Bacillus (3), Microbacterium (3), Agrobacterium (1), Escherichia (1), Delftia (1), Pelomonas (1), Sphingomonas (1), and Staphylococcus (1). All strains produced different amounts of auxin siderophores and formed biofilms. Twelve out of the 16 strains carried the nifH, a gene associated with nitrogen fixation. Co-inoculation of NAB (ESA 424 and ESA 29) with Bradyrhizobium pachyrhizi BR 3262 significantly promoted cowpea growth, especially after simultaneous inoculation with the three strains.
NAB are efficient cowpea growth promoters and can improve the efficiency of the symbiosis between cowpea and the N2-fixing microsymbiont B. pachyrhizi BR 3262, mainly under a specific triple microbial association.
从豇豆根瘤中分离并鉴定非根瘤菌属的根瘤相关细菌（NAB），研究其促进植物生长的机制，以及与慢生根瘤菌共接种时增强豇豆生长和共生的能力。
分离、鉴定了16株NAB，并对其促进植物生长的特性进行了体外评估。在无菌和非无菌基质中，将其与慢生根瘤菌BR 3262共接种，分析其促进豇豆生长的能力。16S rRNA基因序列分析表明，NAB属于金黄杆菌属（4株）、芽孢杆菌属（3株）、微杆菌属（3株）、土壤杆菌属（1株）、埃希氏菌属（1株）、代尔夫特菌属（1株）、食酸菌属（1株）、鞘氨醇单胞菌属（1株）和葡萄球菌属（1株）。所有菌株均产生不同量的生长素铁载体并形成生物膜。16株菌株中有12株携带与固氮相关的nifH基因。将NAB（ESA 424和ESA 29）与慢生根瘤菌BR 3262共接种，显著促进了豇豆生长，尤其是三株菌同时接种后。
NAB是有效的豇豆生长促进剂，能够提高豇豆与固氮微共生体慢生根瘤菌BR 3262之间的共生效率，主要是在特定的三重微生物组合下。
