Phosphate solubilizing rhizobacteria isolated from jujube ziziphus lotus plant stimulate wheat germination rate and seedlings growth

Nidal Fahsi; Ismail Mahdi; Abdelhalem Mesfioui; Latefa Biskri; Abdelmounaaim Allaoui

doi:10.7717/peerj.11583

Phosphate solubilizing rhizobacteria isolated from jujube ziziphus lotus plant stimulate wheat germination rate and seedlings growth

PeerJ. 2021 Jul 2:9:e11583. doi: 10.7717/peerj.11583. eCollection 2021.

Authors

Nidal Fahsi^{1

2}, Ismail Mahdi^{1

3}, Abdelhalem Mesfioui², Latefa Biskri^{4

5}, Abdelmounaaim Allaoui⁴

Affiliations

¹ Institute of Biological Sciences (ISSB-P), Mohammed VI Polytechnic University (UM6P), Benguerir, Morocco.
² Laboratory of Biologie & Sante, Faculty of Sciences, Ibn Tofail University, Kenitra, Morocco.
³ Laboratory of Microbial Biotechnologies, Agrobiosciences and Environement (BioMAgE), Faculty of Sciences Semlalia, University Cadi Ayyad, Marrakesh, Morocco.
⁴ Molecular Microbiology laboratory, Coalition Center of Innovation and Prevention of Epidemies in Morocco (CIPEM), Mohammed VI Polytechnic University (UM6P), Ben Guerir, Morocco.
⁵ African Genome Center (AGC), Mohammed VI Polytechnic University (UM6P), Ben Guerir, Morocco.

Abstract

Jujube plant (Ziziphus lotus (L.) Desf.) can survive in arid climates and tolerates both biotic and abiotic stresses. Here, we isolated, for the first time in Morocco, nine phosphate solubilizing bacteria strains from jujube rhizosphere, designated J10 to J13, J15, & J153 to J156. Genotypic identification based on 16S rDNA sequencing, revealed six strains that belong to Pseudomonas (J10, J12, J13, J15, J153 and J154), two to Bacillus (J11 and J156), and one to Paenibacillus J155. Siderophores were produced by all strains. Proteases activity was missing in Pseudomonas sp. J153 & J154, whereas cellulase was restricted only to Pseudomonas sp. J10, Paenibacillus xylanexedens J155 and Bacillus cereus J156. Indole-3- acetic acid and ammonia were also produced by all strains, with a maxima of 204.28 µg mL^-1 in Bacillus megaterium J11 and 0.33 µmol mL^-1 in Pseudomonas sp. J153, respectively. Pseudomonas sp. J10 and B. cereus J156 grew on plates containing 1,500 µg mL^-1 of nickel nitrate, while Pseudomonas sp. J153 withstood 1,500 µg mL^-1 of either copper sulfate or cadmium sulfate. Phenotypic analysis of the potential of the isolates to promote early plant growth showed that wheat seeds inoculated with either P. moraviensis J12 or B. cereus J156 remarkably increased germination rate and seedlings growth. Lastly, antibiotic resistance profiling revealed that except for Pseudomonas sp. J11 and B. cereus J156, remaining strains displayed resistance at least to one of tested antibiotics. Collectively, Pseudomonas sp. J10, P. moraviensis J12, Pseudomonas sp. J153 and B. cereus J156, represent potential biofertilizers suitable for soils that are poor in P, and/or heavy metals contaminated.

Keywords: Antibiotics resistance; Heavy metals tolerance; Jujube plant; Phosphate solubilizing bacteria; Plant growth promotion.

Grants and funding

This work was supported by a welcome grant of the Mohammed VI polytechnic university (UM6P). Nidal Fahsi and Ismail Mahdi were supported by a PhD thesis grants from the UM6P. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.