Isolation, Characterization of Zn Solubilizing Bacterium (Pseudomonas protegens RY2) and its Contribution in Growth of Chickpea (Cicer arietinum L) as Deciphered by Improved Growth Parameters and Zn Content

Abstract

Background: Zinc is an essential micronutrient required for optimum plant growth. Zinc-solubilizing bacteria convert applied inorganic zinc to available forms that could be used by plants. Research design: In present study, experiments were conducted to isolate, characterize, and evaluate Zn solubilization potential of different bacteria. Results: Among 10 isolated strains, Pseudomonas protegens (RY2, MF351762) was found to be the most promising strain having zinc-solubilizing potential on 4 different insoluble zinc sources. In quantitative assay, Zn solubilization by RY2 was significantly higher than other strains at different incubation time. P. protegens RY2 was selected (based on zinc solubilizing and plant growth promoting activities like P solubilization and ACC deaminase) for plant experiments. Meanwhile, available Zn release rate in soil was determined at day 10 of incubation. Chickpea seeds were inoculated with RY2 strain and ZnO is used as zinc source. Growth parameters and quantifying zinc content of shoot and root using atomic absorption spectrophotometer were determined. Enhanced shoot and root dry weights and lengths were observed in chickpea plants compared to control. Maximum increase of 44%, 67%, and 75% in T2 (Soil + RY2), T5 (Soil + ZnO + RY2), and T7 (Soil + manure + ZnO + RY2), respectively, was found in shoot length compared to control (T1). Conclusion: The study indicated that zinc-solubilizing RY2 strain possesses potential for enhanced Zn in soil so it would allow reduced inorganic Zn application.

Zinc-Solubilizing Streptomyces spp. as Bioinoculants for Promoting the Growth of Soybean (Glycine max (L.) Merrill)

“…CME34 increased the shoot length, root length, number of pods, number of seeds and plant dry weight by 27.98, 24.09, 45.34, 153.97 and 121.01%, respectively, over the uninoculated control. Our results are consistent with other reports on zinc solubilization to improve plant growth by other bacterial genera [ 15 , 71 ]. The results of this pot experiment were well supported by the results of zinc solubilization assay, whereby Streptomyces was capable of producing organic acids to solubilize insoluble forms of zinc in soil and thus enhanced zinc availability for the plants.…”

“…and Gluconacetobacter sp. [ 12 - 15 ]. Among the various bacterial groups, actinobacteria are a group of gram-positive filamentous bacteria and are a major group in rhizosphere soil populations.…”

Biofertilizer effect of some zinc dissolving bacteria free and encapsulated on Zea mays growth

“…When they inoculated wheat plants with these strains, showed enhanced shoot and root length and weight as well as zinc content. While, Yasmin et al ( 2021 ) findings showed that In the treatment with Zn-solubilizing bacteria P. protegens RY2 and ZnO as zinc source, zinc content in both root and shoot was significantly (P 0.05) higher than in the control treatment.. Plant growth and development are enhanced by zinc-solubilizing bacteria colonizing the rhizosphere and intensifying zinc bioavailability by solubilizing complex zinc compounds. Enhancement of the soil microbiome has the potential to increase crop production (Yuan et al 2019 ), and reduce chemical inputs (Thijs et al 2016 ), resulting in more sustainable agricultural practices.…”

Contribution of Biofertilizers to Pulse Crops: From Single-Strain Inoculants to New Technologies Based on Microbiomes Strategies

“…In areas with a low rhizobium population, the addition of Mesorhizobium to the P- and Zn-solubilizing strains was necessary. A Zn-solubilizing strain of Pseudomonas protegens , which also possess P solubilization and ACC deaminase activities, promoted an approximately 40% increase in shoot length compared to control plants [ 157 ].…”