Bacillus Pumilus Strain TUAT-1 and Nitrogen Application in Nursery Phase Promote Growth of Rice Plants under Field Conditions

Abstract

The aims of this study were to boost growth attributes, yield, and nutrient uptake of rice in paddy fields using a combination of Bacillus pumilus strain TUAT-1 biofertilizer and different nitrogen (N) application rates in nursery boxes. Bacillus pumilus strain TUAT-1 was applied as an inoculant biofertilizer in conjunction with different rates of N fertilizer to rice seedlings in a nursery. Plant growth and yield parameters were evaluated at two stages: in 21-day-old nursery seedlings and in mature rice plants growing in a paddy field. Inoculation with TUAT-1 significantly increased the seedling growth and root morphology of 21-day-old nursery seedlings. There was a marked increase in chlorophyll content, plant height, number of tillers, and tiller biomass of rice plants with the use of TUAT-1 and N fertilizers alone, and their combinations, at the maximum tillering stage in the field. The combination of TUAT-1 and 100% N (farmer recommended rate of N) resulted in the greatest tiller number and biomass at the maximum tillering stage, and positively affected other growth attributes and yield. The growth and yield were similar in the TUAT-1 + 50% N and 100% N (uninoculated) treatments, because TUAT-1 promoted root development, which increased nutrient uptake from the soil. These results suggest that the B. pumilus strain TUAT-1 has a potential to enhance the nutritional uptake of rice by promoting the growth and development of roots.

Genome-wide Association Studies Reveal Important Candidate Genes for the Bacillus pumilus TUAT-1-Arabidopsis thaliana Interaction

“…Our results corroborate the Bacillus spp. growth promotion capability (Asari 2017;Win 2018;Win 2020), which is broadly reported. Here we present further insights to the molecular mechanism involved in PGPB.…”

“…For example, analysis of 27 maize inbred lines across different fields, showed that a small but significant fraction of variation in microbial diversity could be attributed to host genetics (PEIFFER, 2013). Bacillus pumilus strain TUAT-1 was isolated in Japan and demonstrated as a plant-growth promoting bacteria (PGPB) for rice, recently released as a commercial inoculant for this crop (Win 2018). TUAT-1 can increase root and shoot fresh weight, number of crown roots, number of lateral roots and total lateral root length in rice (Ngo 2019 for all tested accessions.…”

“…This bacterium produces significant amounts of gibberellins, more than 200 ng.ml -1 after 24 h (Gutierrez-Manero 2001 andLee 2006). B. pumilus was also shown to promote growth and stress tolerance under conditions of drought or high salt stress and has antifungal activity (Gurav 2017 andWin 2018).…”

Complete Genome Sequence of Plant Growth-Promoting Bacillus pumilus TUAT1

“…We screened plant growth-promoting strains from field soils at the Tokyo University of Agriculture and Technology (Tokyo, Japan) and isolated a strain, TUAT1, which was identified as Bacillus pumilus by 16S rRNA gene analysis. TUAT1 promotes the growth of several plants, including that of rice (Oryza sativa L.) and Brassica species (1–5). An inoculant was developed using TUAT1 that has been commercialized in Japan since 2017.…”

Influence of rice-husk biochar and Bacillus pumilus strain TUAT-1 on yield, biomass production, and nutrient uptake in two forage rice genotypes

“…Several root-colonizing Bacillus species are well known for their growth-promoting effect [19]. Previous studies have indicated that Bacillus pumilus strain TUAT-1 (hereafter referred to as TUAT-1) has been found to increase growth in forage rice variety Leaf Star [20]; in the rice variety Koshihikari [21]; and in other crops, including komatsuna, mustard, and radish [22], mainly owing to its potential to increase nutrient uptake by enhancing root growth. Although there is vast amount of data evidence on growth enhancement of TUAT1, to our knowledge, a consistent positive interaction between the bacteria and plant genotype remains unclear.…”