Aug 2026· Discover Biotechnology· Vol 3· 0 citations· 73 references
TL;DR
Plant growth-promoting rhizobacteria consortia are used in the growth and augmentation of Mustard CS61 (Brassica juncea) under saline conditions to discover novel genes associated with stress tolerance and plant growth–promoting traits.
Abstract
Plant growth-promoting rhizobacteria (PGPR) help plants grow and develop by protecting them from abiotic and biotic stresses, thereby increasing biochemicals synthesis that promote growth and nutrients uptake. Soil salinity is a major global constraint on crop productivity, and salt-tolerant PGPR offer a promising mitigation strategy. This study represents the use of PGPR consortia in the growth and augmentation of Mustard CS61 (Brassica juncea) under saline conditions. Mangrove rhizosphere soils collected from Koparkhairane (19.1045° N, 73.0033° E) to Belapur (19.0168° N, 73.0455° E), Navi Mumbai, Maharashtra, India. A total of 1,263 bacterial isolates were obtained, of which 168 isolates were screened for halotolerance. Further on the basis of purity, morphological characteristics, and PGPR traits three isolates were selected. These isolates produced significant amounts of IAA with concentrations of 59.27–81.63 µg mL⁻¹, and prominent CMC activity with hydrolysis zones of 2–5 mm. Molecular identification by 16 S rRNA sequencing revealed the potential isolates as Micrococcus luteus (Accession No. PX974661), Microbacterium barkeri (Accession No. PX974662) and (Accession No. PX974663). Plant growth promotion studies with consortia on salt tolerant variety Mustard CS61 (Brassica juncea L.) under 1% saline conditions showed 100% germination, improved seedling vigour, and increased growth. Future studies using metagenomic approaches are needed to explore the wider uncultured microbial diversity, to discover novel genes associated with stress tolerance and plant growth–promoting traits.
Two mangrove-derived endophytic actinobacteria strains isolated from mangrove forests in Thailand significantly increased rice seedling growth, shoot length, root length, and root weight compared with those of the uninoculated control.
Tipyadapron Pengrung, Aekasit Suphannarot, K. Duangmal et al.· Chiang Mai Journal of Scienc...· 0 citations
The results demonstrate that the combined application of S. wightii extract and PGPR can effectively enhance tomato productivity while reducing fertiliser usage by 25 %, and offers a sustainable approach to improving crop performance and reducing chemical fertiliser dependence.
K. Oviya, J. Jaipriyanka, S. Mahalakshmi et al.· Plant Science Today· 0 citations
Aim: This study was conducted to formulate and evaluate the efficacy of a composite: coir pith + starch + plant-growth-promoting rhizobacteria (PGPR), in sustaining the survival and growth of Zea mays (maize) seeds cultivated under flood stress.
Place and Duration of Study: Department of Microbiology Laboratory, Federal University Otuoke, Bayelsa State, Nigeria, between May and July 2024.
Methodology: Rhizobacteria were isolated, screened for plant-growth-promoting (PGP) traits; phosphate solubilisation and indole-3-acetic acid (IAA) production and further tested for PGP activity via seed germination bioassay. Composites were prepared by homogenizing coir pith, starch gel and standardized PGPR inoculum at a ratio of 2:24:20 (w/v), pelleted and dried at 28 oC. The efficacy of the composites was examined in a pot experiment by measuring shoot length (SL), root length (RL) and plant height (PH), of the treated maize seeds. Treatments were conducted in two sets (single composite pellet and 4 composite pellets); Set 1 (seeds + 1 composite pellet/pot, Control 1 and Control 2), Set 2 (seeds + 4 composite pellets/pot, Control 1 and Control 2). Controls 1 and 2 were; seeds + coir pith + starch only and maize seeds only, respectively. Set 1 was monitored for 2 weeks, and Set 2 for 7 days. Flood conditions were simulated by saturating the pots with water, without drainage, for 3 days.
Results: Five rhizobacteria were isolated; LCE tested positive for IAA production and phosphate solubilisation, SPP tested positive for IAA production only, and C tested positive for phosphate solubilization only. The growth performance of treated maize seeds under waterlogged condition in Set 1 indicated that the Control 1 (maize seeds + 1 coir pith + starch only pellet) was more effective than Control 2 and the other composites. The treatments in Set 1 did not support maize seed growth throughout the two-week monitoring period, except control 1 (maize seeds + 1 coir pith +starch only) which sustained seed survival and growth for 2 weeks. One way ANOVA indicated that the mean growth for control 1 was the same across the weeks as the p-value (p = 0.658) is greater than the 5% significance level (α = 0.05). In Set 2, at day 7, the observed survival and growth of maize seeds treated resulted from the application of 4 coir pith+starch+LCE (Priestia flexa) pellets. The mean SL, RL and PH recorded for the seeds were 2.6±0.2, 3.6±0.45 and 15.9±0.45 cm, respectively. LCE was identified by 16S rRNA sequencing as Priestia flexa.
Conclusion: This study demonstrates the potential of coir pith+ starch+Priestia flexa to mitigate waterlogging stress, sustain survival and growth of Zea mays seedlings.
Brazilian cattle production relies predominantly on pasture systems, many of which are degraded by nutrient depletion, particularly nitrogen deficiency. Plant growth-promoting bacteria (PGPB) offer a sustainable strategy to improve pasture productivity, but their effects are often host-specific and remain poorly explored in Paspalum. This study evaluated the effect of inoculation with Azospirillum brasilense strains CNPSo 2083 (=Ab-V5) and CNPSo 2084 (=Ab-V6) and Pseudomonas fluorescens strain CNPSo 2719 (=CCTB 03), applied by seed inoculation or leaf spray, on the root morphology and shoot growth of four Paspalum accessions under controlled axenic greenhouse conditions, evaluated in an early growth stage at 35 days after emergence. Genotype-specific responses were the central finding of this study: Paspalum malacophyllum BGP-293 showed negligible responses to inoculation, whereas BGP-486—of the same species—increased root dry weight by up to 43% and root tissue density by up to 30% in all inoculated treatments. In Paspalum regnellii BGP-112, seed inoculation produced stronger root responses than foliar spray, increasing root dry weight by up to 38% and root area by up to 40%. In Paspalum rojasii BGP-149, inoculation induced root architectural remodeling without increasing root biomass—root area increased by up to 92% and total root length by up to 97%, relative to the control—indicating an efficient root-foraging strategy. P. fluorescens favored root-foraging traits and tissue density, whereas A. brasilense preferentially stimulated root-hair elongation. These accession-level contrasts, rather than a single generalizable trend, are the main contribution of this work: they support tailored, genotype-specific PGPB strategies for sustainable tropical pastures.
Beatriz Cortellini Ferranti, Gabriela da Silva Guimarães, A. B. Rondina et al.· Plants· 0 citations
Rhizobium spp. inoculation is a strategy to promote plant growth and enhance drought tolerance, particularly in semiarid environments. This study evaluated the morphological and physiological responses of Mimosa tenuiflora (Willd.) seedlings inoculated with Rhizobium spp. under different water contents. Seeds were collected from 12 naturally growing mother trees (Patos, Paraíba, Brazil). No specific genotype or cultivar was used. A completely randomized experiment was conducted in a 5 × 2 factorial design with four replicates, comprising five treatments (inoculation with three Rhizobium spp. strains: CA19PT, RO19PT, and MK17PT; nitrogen fertilization; and a non-inoculated control) under two water-content levels (40% and 80% of pot capacity). M. tenuiflora seedlings were grown in 3 dm³ pots for 90 days, after which growth, biomass production, nodulation, relative water content (RWC), and gas exchange parameters were evaluated. The results demonstrated that physiological variables were influenced by the treatments and water availability, whereas growth variables were affected only by water availability. Among the evaluated treatments, inoculation with strain CA19PT showed physiological responses comparable to those observed under nitrogen fertilization. Even under low water availability (40% pc, seedlings maintained adequate hydration levels, with an increase in root biomass. Inoculation with selected Rhizobium isolates, particularly CA19PT, improved the physiological performance of M. tenuiflora seedlings under contrasting water-content conditions. Physiological responses observed in seedlings inoculated with CA19PT were comparable to those obtained with nitrogen fertilization. Additionally, seedlings grown under higher water content (80% pc exhibit better overall growth, whereas reducing water content to 40% pcstimulates root growth.
Erika Rayra Lima Nonato, Carlos Luiz da Silva, Moema Barbosa de Sousa et al.· Discover Plants· 0 citations
Soil salinity remains a major abiotic factor limiting agricultural productivity worldwide, with the situation worsening in parts of Maharashtra, particularly Karad Taluka. This study examined saline soils from various locations within Karad, assessing their physicochemical properties and isolating indigenous halotolerant bacterial strains that exhibit plant growthpromoting rhizobacterial (PGPR) traits. The soil analysis revealed highly alkaline pH levels (8.8-9.4), elevated sodium concentrations, and deficiencies in organic carbon, nitrogen, and micronutrients. Five halotolerant bacterial isolates (Ko1, Va1, Be1, Vm1, and At1) were obtained and evaluated for PGPR activities such as phosphate and potassium solubilization, nitrogen fixation, indole-3-acetic acid (IAA) production, and siderophore synthesis. All isolates demonstrated positive results in phosphate and potassium solubilization, nitrogen fixation, and IAA production, with four also producing siderophores. Notably, isolates Be1, Vm1, and At1 showed strong performance across multiple traits, highlighting their potential as bioinoculant candidates. These findings suggest that native halotolerant PGPR strains from Karad Taluka could enhance soil fertility, improve nutrient uptake, and support plant growth in saline conditions. Future research including field trials and molecular characterization could facilitate the development of environmentally sustainable microbial formulations for saline agriculture.
Priyadarshani A. Patil, Aparna G Pathade, Girish R. Pathade· Nature Environment and Pollu...· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
