A group from Department of Microbiology, Himachal Pradesh University, Summerhill, Shimla, India, etc. has reprted about plant growth promoting Bacteria (PGPB) for Enhancing Growth of Rice Crops.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10142854/
This investigation was undertaken with the aim of selecting multifarious plant growth-promoting Bacillus strains from the rice rhizosphere. The individual inoculation of seeds and coinoculation of Bacillus strains (Bacillus licheniformis MNNITSR2 and Bacillus velezensis MNNITSR18) showed a significant increase in overall plant growth without any chemical fertilizer amendments such as the murate of potash, diammonium phosphate and urea, etc. In detail, Bacillus MNNIT SR2 showed a significant increase in fresh shoot and root length (14.7% and 30.8%, respectively) and the dry weight of the shoot and root (53% and 35.6%, respectively) of rice plants after eight weeks compared to the untreated control in the pot culture assay. Similar results were obtained with Bacillus velezensis MNNIT SR18 which also increased the fresh shoot and root length (17% and 20%) and the dry weight of the shoot and root (88.3% and 83.7%) of rice plants after eight weeks compared to the untreated control in the pot culture assay.
These Bacillus strains show the following plant growth promoting activities.
IAA Production: which regulates various physiological processes, including root initiation, cell enlargement, and the stimulation of cell division, and results in an increase in the root surface area while enabling the plant to take up significantly more nutrients from the soil.
Phosphate Solubilization: Plants utilize only inorganic phosphorus, and organic phosphorus compounds must first be hydrolyzed by phosphatase enzymes.
Siderophore Production: which chelates iron in the rhizosphere and prevents fungal pathogens from flourishing in iron-limiting conditions.
Antifungal Activity: both strains were able to inhibit the mycelial growth of F. oxysporum and R. solani.
HCN Production: which affects the respiratory system of plant pathogenic fungi and leads to the inhibition of their mycelial growth.
Ammonia Production: which directly promotes plant growth and productivity
ACC Deaminase Activity: which has beneficial effects on the growth of plants by reducing the concentration of ACC under a wide range of different abiotic stresses, viz., salt stress, flooding stress, heavy metal stress, and pathogen attack
Abiotic Stress Tolerance Activity: both strains also showed salt and drought tolerance and were found to be resistant to 10–15% NaCl and 25% PEG 6000, respectively