Diversity and plant growth promoting properties of rhizobia isolated from root nodules of Ononis arvensis

Abstract

This is the first report describing isolates from root nodules of Ononis arvensis (field restharrow). The aim of this investigation was to describe the diversity, phylogeny, and plant growth promoting features of microsymbionts of O. arvensis, i.e., a legume plant growing in different places of the southern part of Poland. Twenty-nine bacterial isolates were characterized in terms of their phenotypic properties, genome fingerprinting, and comparative analysis of their 16S rRNA, nodC and acdS gene sequences. Based on the nodC and 16S rRNA gene phylogenies, the O. arvensis symbionts were grouped close to bacteria of the genera Rhizobium and Mesorhizobium, which formed monophyletic clusters. The acdS gene sequences of all the isolates tested exhibited the highest similarities to the corresponding gene sequences of genus Mesorhizobium strains. The presence of the acdS genes in the genomes of rhizobia specific for O. arvensis implies that these bacteria may promote the growth and development of their host plant in stress conditions. The isolated bacteria showed a high genomic diversity and, in the BOX-PCR reaction, all of them (except three) exhibited DNA fingerprints specific only for them. Our studies showed that restharrow isolates formed effective symbiotic interactions with their native host (O. arvensis) and Ononis spinosa but not with Trifolium repens and Medicago sativa belonging to the same tribe Trifolieae as Ononis species and not with Lotus corniculatus, representing the tribe Loteae.

Modified microplate method for rapid and efficient estimation of siderophore produced by bacteria

“…Members of the family Rhizobiaceae (except R. radiobacter LB2 and R. meliloti RMP5) were not very efficient producers of siderophore, and in general, also researchers have not found rhizobia to be prolific producers of siderophores (Joseph et al 2007 ; de Souza et al 2015 ). Very few studies report that rhizobia are good producers of siderophores (Berraho et al 1997 ; Arora et al 2001 ; Duhan 2013 ; Wdowiak-Wróbel et al 2017 ). Endophytic strain K. pseudosacchari (LN) is being reported for the first time as an efficient siderophore producer.…”

Plant growth‐promoting rhizobacterial communities from an area under the influence of iron mining and from the adjacent phytophysiognomies which have high genetic diversity

“…The diversity of RA similar to AF shows that grass was efficient in stimulating and maintaining a community of plant growth-promoting bacteria, which was not only diverse, but also efficient (Figures 1 and 5, and Table 1). These bacteria are multifunctional, and are able to promote symbiotic and associative biological N 2 fixation, produce phytohormones and siderophores, and solubilize phosphate (Angus et al, 2013;Costa et al, 2016;Rangel et al, 2016;Velázquez et al, 2017;Wdowiak-Wróbel et al, 2017); they may be acting in restoration of this area by means of these processes.…”

“…Among these processes, we emphasize biological nitrogen fixation (BNF), carried out by symbiotic and associative diazotrophic bacteria, which is extremely important for the ecosystems by making nitrogen available in a form that can be assimilated by plants, which promotes greater plant development. Nevertheless, promotion of plant growth can be achieved through other processes, such as phytohormone production (Costa et al, 2016), phosphate solubilization (Angus et al, 2013;Costa et al, 2016), siderophore production (Wdowiak-Wróbel et al, 2017), and adaptation to stresses, such as tolerance to metals (Rangel et al, 2016), in leguminous and non-leguminous plants (Velázquez et al, 2017).…”

Endophytic Bacteria Potentially Promote Plant Growth by Synthesizing Different Metabolites and their Phenotypic/Physiological Profiles in the Biolog GEN III MicroPlateTM Test

“…Based on the metabolic and physiological properties of bacteria, their diversity can be determined as well as PGPB that have a positive impact on the plant growth can be selected. Polyphasic taxonomy based on different types of data from phenotypic, genomic and phylogenetic analysis is currently most commonly used to identify microorganisms [10]. Phenotypic analysis allows preliminary classification of bacteria into the genus and even to the species level.…”