Year-end Sale % OFF 
Abstract
Species in the genus Paenibacillus from special habitats have attracted great attention due to their plant growth-promoting traits. A novel plant growth-promoting rhizobacteria (PGPR) species in the genus Paenibacillus was isolated from spruce forest at the height of 3,150 m in the Qilian Mountains, Gansu province, China. The phylogenetic analysis based on 16S rRNA, rpoB, and nifH gene sequences demonstrated that strain LC-T2T was affiliated in the genus Paenibacillus and exhibited the highest sequence similarity with Paenibacillus donghaensis KCTC 13049T (97.4%). Average nucleotide identity (ANIb and ANIm) and digital DNA–DNA hybridization (dDDH) between strain LC-T2T and P. donghaensis KCTC 13049T were 72.6, 83.3, and 21.2%, respectively, indicating their genetic differences at the species level. These differences were further verified by polar lipids profiles, major fatty acid contents, and several distinct physiological characteristics. Meanwhile, the draft genome analysis provided insight into the genetic features to support its plant-associated lifestyle and habitat adaptation. Subsequently, the effects of volatile organic compound (VOC) emitted from strain LC-T2T on the growth of Arabidopsis were evaluated. Application of strain LC-T2T significantly improved root surface area, root projection area, and root fork numbers by 158.3, 158.3, and 241.2%, respectively, compared to control. Also, the effects of LC-T2T on the growth of white clover (Trifolium repens L.) were further assessed by pot experiment. Application of LC-T2T also significantly improved the growth of white clover with root fresh weight increased over three-folds compared to control. Furthermore, the viable bacterial genera of rhizosphere soil were detected in each treatment. The number of genera from LC-T2T-inoculated rhizosphere soil was 1.7-fold higher than that of control, and some isolates were similar to strain LC-T2T, indicating that LC-T2T inoculation was effective in the rhizosphere soil of white clover. Overall, strain LC-T2T should be attributed to a novel PGPR species within the genus Paenibacillus based on phylogenetic relatedness, genotypic features, and phenotypic and inoculation experiment, for which the name Paenibacillus monticola sp. nov. is proposed.
Highlights
Plant growth-promoting rhizobacteria (PGPR) enhance growth and health of host plants through various mechanisms, including phosphate solubilization, nitrogen fixation, siderophore production, synthesis of phytohormone, and emission of volatile organic compounds (VOCs) (Ryu et al, 2003; Fürnkranz et al, 2012; Grady et al, 2016; He et al, 2021)
Comparative analysis built on 16S rRNA gene sequence revealed that strain LC-T2T was phylogenetically affiliated to the genus Paenibacillus in the family Paenibacillaceae
On the basis of phylogenetic analysis, the highest level of similarity was found between strain LC-T2T and P. donghaensis Korean Collection for Type Cultures (KCTC) 13049T (97.4%), followed by P. odorifer Japan Collection of Microorganisms (JCM) 21743T (96.8%) and other recognized members of the genus Paenibacillus (
Summary
Plant growth-promoting rhizobacteria (PGPR) enhance growth and health of host plants through various mechanisms, including phosphate solubilization, nitrogen fixation, siderophore production, synthesis of phytohormone, and emission of volatile organic compounds (VOCs) (Ryu et al, 2003; Fürnkranz et al, 2012; Grady et al, 2016; He et al, 2021). Many PGPRs prevent rhizosphere colonization of pathogenic or parasitic organisms by secreting antagonistic compounds and inducing plant defenses and/or competition for nutrients (Backer et al, 2018; Woo and Pepe, 2018; Naamala and Smith, 2021) These valuable characteristics can help to reduce the dependence of agricultural production on chemical fertilizers and insecticides, maximize the ecological benefits, and accelerate the emergence of their applications in biotechnological processes (Backer et al, 2018; Woo and Pepe, 2018; Rani et al, 2021). Only a few species of Paenibacillus have been explored in detail concerning their effects on the growth of forage crops
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
