Deciphering the impact of cold-adapted bioinoculants on rhizosphere dynamics, biofortification, and yield of kidney bean across varied altitudinal zones.

Agriculture stands as a thriving enterprise in India, serving as both the bedrock of economy and vital source of nutrition. In response to the escalating demands for high-quality food for swiftly expanding population, agricultural endeavors are extending their reach into the elevated terrains of the Himalayas, tapping into abundant resources for bolstering food production. Nonetheless, these Himalayan agro-ecosystems encounter persistent challenges, leading to crop losses. These challenges stem from a combination of factors including prevailing frigid temperatures, suboptimal farming practices, unpredictable climatic shifts, subdivided land ownership, and limited resources. While the utilization of chemical fertilizers has been embraced to enhance the quality of food output, genuine concerns have arisen due to the potential hazards they pose. Consequently, the present investigation was initiated with the objective of formulating environmentally friendly and cold-tolerant broad ranged bioinoculants tailored to enhance the production of Kidney bean while concurrently enriching its nutrient content across entire hilly regions. The outcomes of this study unveiled noteworthy advancements in kidney bean yield, registering a substantial increase ranging from 12.51 ± 2.39 % to 14.15 ± 0.83 % in regions of lower elevation (Jeolikote) and an even more remarkable surge ranging from 20.60 ± 3.03 % to 29.97 ± 5.02 % in higher elevated areas (Chakrata) compared to the control group. Furthermore, these cold-tolerant bioinoculants exhibited a dual advantage by fostering the enhancement of essential nutrients within the grains and fostering a positive influence on the diversity and abundance of microbial life in the rhizosphere. As a result, to effectively tackle the issues associated with chemical fertilizers and to achieve sustainable improvements in both the yield and nutrient composition of kidney bean across varying elevations, the adoption of cold-tolerant Enterobacter hormaechei CHM16, and Pantoea agglomerans HRM 23, including the consortium, presents a promising avenue. Additionally, this study has contributed significant insights-into the role of organic acids like oxalic acid in the solubilization of nutrients, thereby expanding the existing knowledge in this specialized field.

Microbial bioformulation: a microbial assisted biostimulating fertilization technique for sustainable agriculture.

Addressing the pressing issues of increased food demand, declining crop productivity under varying agroclimatic conditions, and the deteriorating soil health resulting from the overuse of agricultural chemicals, requires innovative and effective strategies for the present era. Microbial bioformulation technology is a revolutionary, and eco-friendly alternative to agrochemicals that paves the way for sustainable agriculture. This technology harnesses the power of potential microbial strains and their cell-free filtrate possessing specific properties, such as phosphorus, potassium, and zinc solubilization, nitrogen fixation, siderophore production, and pathogen protection. The application of microbial bioformulations offers several remarkable advantages, including its sustainable nature, plant probiotic properties, and long-term viability, positioning it as a promising technology for the future of agriculture. To maintain the survival and viability of microbial strains, diverse carrier materials are employed to provide essential nourishment and support. Various carrier materials with their unique pros and cons are available, and choosing the most appropriate one is a key consideration, as it substantially extends the shelf life of microbial cells and maintains the overall quality of the bioinoculants. An exemplary modern bioformulation technology involves immobilizing microbial cells and utilizing cell-free filters to preserve the efficacy of bioinoculants, showcasing cutting-edge progress in this field. Moreover, the effective delivery of bioformulations in agricultural fields is another critical aspect to improve their overall efficiency. Proper and suitable application of microbial formulations is essential to boost soil fertility, preserve the soil's microbial ecology, enhance soil nutrition, and support crop physiological and biochemical processes, leading to increased yields in a sustainable manner while reducing reliance on expensive and toxic agrochemicals. This manuscript centers on exploring microbial bioformulations and their carrier materials, providing insights into the selection criteria, the development process of bioformulations, precautions, and best practices for various agricultural lands. The potential of bioformulations in promoting plant growth and defense against pathogens and diseases, while addressing biosafety concerns, is also a focal point of this study.

Credibility assessment of cold adaptive Pseudomonas jesenni MP1 and P. palleroniana N26 on growth, rhizosphere dynamics, nutrient status, and yield of the kidney bean cultivated in Indian Central Himalaya.

Kidney bean (Phaseolus vulgaris) productivity and nutritional quality are declining due to less nutrient accessibility, poor soil health, and indigent agronomic practices in hilly regions, which collectively led to a fall in farmer's income, and to malnutrition in consumers. Addressing such issues, the present investigation was designed to assess the impact of Pseudomonas jesenii MP1 and Pseudomonas palleroniana N26 treatment on soil health, microbial shift, yield, and nutrient status of the kidney bean in the Harsil and Chakrata locations of Indian Central Himalaya. P. jesenii MP1 and P. palleroniana N26 were characterized as cold adaptive PGPR as they possessed remarkable in vitro plant growth promoting traits. Further, field trial study with PGPR treatments demonstrated remarkable and prolific influence of both strains on yield, kidney bean nutrient status, and soil health at both geographical locations, which was indicated with improved grain yield (11.61%-23.78%), protein (6.13%-24.46%), and zinc content (21.86%-61.17%) over control. The metagenomic study revealed that use of bioinoculants also concentrated the nutrient mobilizing and plant beneficial microorganisms in the rhizosphere of the kidney bean. Moreover, correlation analysis also confirmed that the plant growth-promoting traits of P. jesenii MP1 and P. palleroniana N26 are the basis for improved yield and nutrient status of the kidney bean. Further, cluster and principal component analysis revealed that both P. jesenii MP1 and P. palleroniana N26 exhibited pronounced influence on yield attributes of the kidney bean at both the locations. At the Harsil location, the P. jesenii MP1-treated seed demonstrated highest grain yield over other treatments, whereas at Chakarata, P. jesenii MP1, and P. palleroniana N26 treatment showed almost equal enhancement (~23%) in grain yield over control. The above results revealed that these bioinoculants are efficient plant growth promoters and nutrient mobilizers; they could be used as green technology to improve human health and farmer's income by enhancing soil health, yield, and nutrient status of the kidney bean at hilly regions.

Prolific contribution of Pseudomonas protegens in Zn biofortification of wheat by modulating multifaceted physiological response under saline and non-saline conditions.

The current study aimed to characterize the contribution of bacterium CP17 in zinc (Zn) biofortification in wheat under saline and non-saline conditions. This bacterial strain effectively solubilized Zn and tolerated up to 20% NaCl concentration. The Zn-solubilization potential was also quantified using AAS in a liquid broth supplemented with zinc oxide and zinc carbonate at various NaCl concentrations. Lowering the pH of liquid broth and analyzing a wide range of organic acids (thioacetic acid, glutamic acid, carboxylic acid, propionic acid, and so on) using UPLC-MS provided mechanistic insight for zinc solubilization. This strain was also shown to possess plant probiotic characteristics like phosphate solubilization, production of siderophore, indole acetic acid (IAA), exopolysaccharide (EPS), ACC deaminase, and ammonia. CP17 was identified as a Pseudomonas protegens based on the 16S rRNA gene analysis. In addition, the amplified product of the ACC deaminase producing gene (acdS) provided a molecular indication of the strain's endurance towards stress. The towel paper assay confirmed that the inoculation of Pseudomonas protegens CP17 significantly increased wheat seedlings' germination, growth, and biomass under different NaCl concentrations (0 mM, 100 mM, and 150 mM). Afterward, In situ pot experiment study was designed with the inoculation of Pseudomonas protegens in wheat under saline and non-saline conditions. The harvested wheat plants showed an elevated pattern of zinc content in the grain (i.e. 24.33 and 29.33mg/kg), straw (i.e. 45.73 and 50.23mg/kg) and soil (i.e. 0.978 and 1.32mg/kg) under saline and non-saline conditions, respectively and shown significant improvement over control. The results of the pot study revealed the amelioration in plant health, yield and uptake of available zinc from rhizospheric soil to straw and grain, along with enhanced dehydrogenase and phosphatase activities of rhizospheric soil under saline and non-saline conditions. This study supports the integrative role of Pseudomonas protegens CP17 as a bioinoculant for the efficacious strategy of zinc biofortification and growth promotion in wheat and ensures sustainable nutrient quality production under salinity stress.

FE-SEM/EDX Based Zinc Mobilization Analysis of Burkholderia cepacia and Pantoea rodasii and Their Functional Annotation in Crop Productivity, Soil Quality, and Zinc Biofortification of Paddy.

The experimental study was contrived to characterize two zinc-solubilizing bacteria (ZSB), namely BMRR126 and BMAR64, and their role in zinc (Zn) biofortification of rice. These bacteria solubilized Zn profoundly, determined qualitatively by halo-zone formation on a solid medium and quantitatively in a liquid broth by AAS and SEM-EDX. The lowering of pH and contact angle assessment of the liquid broth unveiled the establishment of the acidic conditions in a medium suitable for Zn solubilization. The characterization of both isolates on the basis of 16S rRNA gene analysis was identified as Burkholderia cepacia and Pantoea rodasii, respectively. These strains were also found to have some plant probiotic traits namely phosphate solubilization, production of siderophore, indole acetic acid (IAA), exopolysaccharide (EPS), and ammonia. The field experiments were performed at two diverse locations and under all treatments; the simultaneous use of BMRR126 and BMAR64 with zinc oxide (ZnO) resulted in the highest growth and productivity of the paddy crop. The utmost Zn achievement in the grain was estimated in a treatment (T9) (25.07 mg/kg) containing a consortium of BMRR126 and BMAR64 along with ZnO for the Terai region. The treatment containing single ZSB bioinoculant BMRR126 (T7) showed an elevated Zn amount in the rice grain (33.25 mg/kg) for the Katchar region. The soil parameters (pH, EC, organic carbon, NPK, available Zn, and dehydrogenase activity) were also positively influenced under all bacterial treatments compared to the uninoculated control. Our study clearly accentuates the need for Zn solubilizing bacteria (ZSB) to provide the benefits of Zn-biofortification in different regions.

Multifarious effect of ACC deaminase and EPS producing Pseudomonas sp. and Serratia marcescens to augment drought stress tolerance and nutrient status of wheat.

Drought is the prime abiotic stress that rigorously influences plant growth, yield and quality of crops. The current investigation illustrated the bio-protective characters of Serratia marcescens and Pseudomonas sp. to ameliorate drought stress tolerance, plant growth and nutrient status of wheat. The present study aimed for search of potential drought tolerant plant growth-promoting rhizobacteria (PGPR). All screened bacterial isolates exhibited potential plant growth promoting (PGP) attributes such as production of ACC deaminase, exo-polysaccharide, siderophore, ammonia, IAA, and efficiently solubilized zinc and phosphate under in vitro conditions. To assess the in situ plant growth promotion potential of PGPR, a greenhouse experiment was conducted by priming wheat seeds with screened plant PGPR. Improved water status, reactive oxygen species, osmolyte accumulation, chlorophyll and carotenoids content in plant leaves confirmed the excellent drought tolerance conferring ability of RRN II 2 and RRC I 5. Among all PGPR, RRN II 2 and RRC I 5 inoculated plants not only demonstrated greater harvest index but also exhibited more micronutrient (zinc and iron) content in wheat grains. Further, RRN II 2 and RRC I 5 were identified through 16S rDNA sequencing as S. marcescens and Pseudomonas sp., respectively. Furthermore, amplification of acdS gene (Amplified band size of acdS gene was ~ 1.8 Kb) also confirmed ACC deaminase enzyme producing ability of Pseudomonas sp. Moreover, correlation coefficient, principal component analysis and cluster analysis also demonstrated that nutrient status and values of agronomical parameters of wheat primed with S. marcescens and Pseudomonas sp. were at par with the positive control. Thus, the outcome of this comparative investigation indicates that Pseudomonas sp. and S. marcescens could be utilized as bioinoculant in wheat since they can improve the physiological status, productivity and nutrient status in wheat crop under drought.