Co-Inoculation of Endophytes Bacillus siamensis TUR07-02b and Priestia megaterium SMBH14-02 Promotes Growth in Rice with Low Doses of Nitrogen Fertilizer

Abstract

Multiple biotic and abiotic factors influence rice cultivation. These factors limit productivity and yield, as well as an irrational use of agrochemicals in rice cultivation. A sustainable alternative is using selected growth-promoting microorganisms to increase nutritional efficiency. In the present study, the direct mechanisms of growth promotion in two strains of Bacillus, three strains of Priestia, and two strains of Burkholderia endophytes of rice were characterized. Bacillus siamensis TUR07-02b and Priestia megaterium SMBH14-02 were selected to promote Oryza sativa var’s growth. “Bellavista” was used at different doses (50, 75, and 100%) of mineral nitrogen (N) using a randomized block design by quintuplicate. Both strains, SMBH14-02 and TUR07-02b, presented outstanding promoter characteristics, including auxin production (123.17 and 335.65 μg mL−1, respectively) and biological nitrogen fixation capacity. Similarly, B. siamensis TUR07-02b could solubilize phosphate-Ca (20.94 μg mL−1), cellulases, and pectinases. Under greenhouse conditions, co-inoculated plants receiving 75% of the total dose of mineral nitrogen showed increased agronomic parameters in relation to panicle length, grains per panicle, grain yield, and harvest index by 25.0, 30.7, 39.5, and 12.5%, respectively, compared to the 75% fertilized treatment without inoculation. The strains of B. siamensis TUR07-02b and P. megaterium SMBH14-02 are potential microbial resources in the formulation of new inoculants to reduce the use of nitrogenous fertilizers. Thus, agronomic validation of the inoculant consortium at the field level will be an essential step in providing an alternative for the sustainable management of rice cultivation and increased productivity of rice farmers in the San Martín region.

Introducing the Power of Plant Growth Promoting Microorganisms in Soilless Systems: A Promising Alternative for Sustainable Agriculture

“…Our search showed that the soilless observed trends in overall yield growth were similar to those reported in studies that employed PGPM in soil-based cropping systems; AMF inoculation in hydroponics, under reduced nutrient levels, increased the total yield by 49.54%, which is consistent with results obtained in soil cultivations (46-50% increase) [85]. In addition, endophytes were shown to increase total yield by 22.12%, just as demonstrated under limited-N soil conditions (31-39% increase) [86].…”

The Complex GH32 Enzyme Orchestra from Priestia megaterium Holds the Key to Better Discriminate Sucrose-6-phosphate Hydrolases from Other β-Fructofuranosidases in Bacteria

“…subtilis and P. megaterium have been reported to be closely associated with plant microbial communities and to have plant-growth and disease-suppressing properties. – Comparison of the GH32-encoding genes in publicly available genomes of both species reveals a special set of intracellular enzymes in P. megaterium of which only one homologue is present in B.…”

Rhizospheric Bacteria of Cover Legumes from Acidic Soils Are Capable of Solubilizing Different Inorganic Phosphates

“…Rhizospheric bacteria play a fundamental role in plant health and productivity through establishing close symbiotic relationships with plant roots, specifically in the zone known as the rhizosphere. This beneficial relationship influences multiple aspects of plant growth, such as nitrogen fixation, nutrient solubilization, the production of indole acetic acid and siderophores, and protection against pathogens [ 1 , 2 ]. Additionally, cover crop legumes represent a valuable tool for promoting sustainable agricultural practices, providing multiple benefits for soil health, biodiversity, and agricultural productivity [ 3 ].…”