Cold-tolerant phosphate-solubilizing Pseudomonas strains promote wheat growth and yield by improving soil phosphorous (P) nutrition status

Hemant Dasila; V K Sah; Vandana Jaggi; Arun Kumar; Lakshmi Tewari; Gohar Taj; Sumit Chaturvedi; Kahkashan Perveen; Najat A Bukhari; Tan Ching Siang; Manvika Sahgal

doi:10.3389/fmicb.2023.1135693

Cold-tolerant phosphate-solubilizing Pseudomonas strains promote wheat growth and yield by improving soil phosphorous (P) nutrition status

Front Microbiol. 2023 Mar 13:14:1135693. doi: 10.3389/fmicb.2023.1135693. eCollection 2023.

Authors

Hemant Dasila^{1

2}, V K Sah³, Vandana Jaggi⁴, Arun Kumar⁵, Lakshmi Tewari², Gohar Taj⁶, Sumit Chaturvedi³, Kahkashan Perveen⁷, Najat A Bukhari⁷, Tan Ching Siang⁸, Manvika Sahgal²

Affiliations

¹ Department of Microbiology, Akal College of Basic Sciences, Eternal University, Rajgarh, Himachal Pradesh, India.
² Department of Microbiology, College of Basic Sciences and Humanities, G.B. Pant University of Agriculture and Technology, Pantnagar, India.
³ Department of Agronomy, College of Agriculture, G.B. Pant University of Agriculture and Technology, Pantnagar, India.
⁴ Department of Pediatrics and Human Development, Michigan State University, Grand Rapids, MI, United States.
⁵ Department of Agronomy, Dr. Khem Singh Gill, Akal College of Agriculture, Eternal University, Rajgarh, Himachal Pradesh, India.
⁶ Department of Molecular Biology and Biotechnology, College of Basic Sciences and Humanities, G.B. Pant University of Agriculture and Technology, Pantnagar, India.
⁷ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia.
⁸ School of Pharmacy, KPJ Healthcare University College, Nilai, Malaysia.

Abstract

It is well-known that phosphate-solubilizing bacteria (PSB) promote crop growth and yield. The information regarding characterization of PSB isolated from agroforestry systems and their impact on wheat crops under field conditions is rarely known. In the present study, we aim to develop psychrotroph-based P biofertilizers, and for that, four PSB strains (Pseudomonas sp. L3, Pseudomonas sp. P2, Streptomyces sp. T3, and Streptococcus sp. T4) previously isolated from three different agroforestry zones and already screened for wheat growth under pot trial conditions were evaluated on wheat crop under field conditions. Two field experiments were employed; set 1 includes PSB + recommended dose of fertilizers (RDF) and set 2 includes PSB - RDF. In both field experiments, the response of the PSB-treated wheat crop was significantly higher compared to the uninoculated control. In field set 1, an increase of 22% in grain yield (GY), 16% in biological yield (BY), and 10% in grain per spike (GPS) was observed in consortia (CNS, L3 + P2) treatment, followed by L3 and P2 treatments. Inoculation of PSB mitigates soil P deficiency as it positively influences soil alkaline phosphatase (AP) and soil acid phosphatase (AcP) activity which positively correlated with grain NPK %. The highest grain NPK % was reported in CNS-treated wheat with RDF (N-0.26%, P-0.18%, and K-1.66%) and without RDF (N-0.27, P-0.26, and K-1.46%), respectively. All parameters, including soil enzyme activities, plant agronomic data, and yield data were analyzed by principal component analysis (PCA), resulting in the selection of two PSB strains. The conditions for optimal P solubilization, in L3 (temperature-18.46, pH-5.2, and glucose concentration-0.8%) and P2 (temperature-17°C, pH-5.0, and glucose concentration-0.89%), were obtained through response surface methodology (RSM) modeling. The P solubilizing potential of selected strains at <20°C makes them a suitable candidate for the development of psychrotroph-based P biofertilizers. Low-temperature P solubilization of the PSB strains from agroforestry systems makes them potential biofertilizers for winter crops.

Keywords: PSB; fertilizer; principal component analysis; psychrotroph; response surface methodology.

Grants and funding

The authors would like to acknowledge the support provided by Researchers Supporting Project Number RSP2023R358, King Saud University, Riyadh, Saudi Arabia. The authors also gratefully acknowledge Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, India, for providing field and research support.