Isolation and characterization of a β-propeller gene containing phosphobacterium Bacillus subtilis strain KPS-11 for growth promotion of potato (Solanum tuberosum L.)

Abstract

Phosphate-solubilizing and phytate-mineralizing bacteria collectively termed as phosphobacteria provide a sustainable approach for managing P-deficiency in agricultural soils by supplying inexpensive phosphate to plants. A phosphobacterium Bacillus subtilis strain KPS-11 (Genbank accession no. KP006655) was isolated from potato (Solanum tuberosum L.) rhizosphere and characterized for potato plant growth promoting potential. The strain utilized both Ca-phosphate and Na-phytate in vitro and produced 6.48 μg mL-1 indole-3-acetic acid in tryptophan supplemented medium. P-solubilization after 240 h was 66.4 μg mL-1 alongwith the production of 19.3 μg mL-1 gluconic acid and 5.3 μg mL-1 malic acid. The extracellular phytase activity was higher (4.3 × 10-10 kat mg-1 protein) than the cell-associated phytase activity (1.6 × 10-10 kat mg-1 protein). B. subtilis strain KPS-11 utilized 40 carbon sources and showed resistance against 20 chemicals in GENIII micro-plate system demonstrating its metabolic potential. Phytase-encoding gene β-propeller (BPP) showed 92% amino acid similarity to BPP from B. subtilis (accession no.WP_014114128.1) and 83% structural similarity to BPP from B. subtilis (accession no 3AMR_A). Potato inoculation with B. subtilis strain KPS-11 increased the root/shoot length and root/shoot weight of potato as compared to non-inoculated control plants. Moreover, rifampicin-resistant derivative of KPS-11 were able to survive in the rhizosphere and on the roots of potato up to 60 days showing its colonization potential. The study indicates that B. subtilis strain KPS-11 can be a potential candidate for development of potato inoculum in P-deficient soils.

A phytobeneficial strainPlanomicrobiumsp. MSSA-10 triggered oxidative stress responsive mechanisms and regulated the growth of pea plants under induced saline environment

“…Rhizobacteria release growth promoting factors, enhance mobilization of soil‐bound minerals (making them available to plants), possess 1 aminocyclopropane‐1‐carboxylicacid (ACC) deaminase activity and induce up‐regulation of genes involved in coping the abiotic and biotic stresses (Hanif et al . ; Hussain et al . ; Shahid et al .…”

“…This has also led to development of microbe-assisted soil reclamation strategies. Rhizobacteria release growth promoting factors, enhance mobilization of soil-bound minerals (making them available to plants), possess 1 aminocyclopropane-1-carboxylicacid (ACC) deaminase activity and induce up-regulation of genes involved in coping the abiotic and biotic stresses (Hanif et al 2015;Hussain et al 2015;Shahid et al 2015;Akram et al 2016). It has been established that PGPR-assisted improvement of salt effected soil is one of the promising approaches for utilization of such soils for crop cultivation (Dodd and P erez-Alfocea 2012).…”

Sugarcane growth and nutrition levels are differentially affected by the application of PGPR and cane waste

“…Several isolates of Bacillus , especially Bacillus subtilis directly affect plant growth promotion, by the mechanisms such as acting as nitrogen fixers, as well as producers of indol butyric acid (IBA) (Araujo, Henning, & Hungria, ), indol acetic acid (IAA), and siderophores (Puente, Bashan, Li, & Lebsky, ), in addition to biocontrol activity (Ali, Charles, & Glick, ; Hanif et al., ; Oslizlo et al., ) and activities of protein expression relevant to the pharmaceutical and industrial sector (Guan et al., ). Bacillus subtilis has such varied functional capacities, which suggests that it has a versatile potential to be used as a plant growth promoter.…”

Isolation and Characterization of a Phosphorus-Solubilizing Bacterium from Rhizosphere Soils and Its Colonization of Chinese Cabbage (Brassica campestris ssp. chinensis)

“…These bacteria have the ability to convert insoluble P into an available form (Hanif et al, 2015). The use of PSB in sustainable agriculture has increasingly attracted the attention of scientists (Hameeda et al, 2008).…”