Growth promotion ability of phosphate‐solubilizing bacteria from the soybean rhizosphere under maize–soybean intercropping systems

Abstract

BACKGROUND Optimum cultivation and management measures are needed to increase the phosphorus (P) absorption efficiency of crops for sustainable agricultural production. Previous studies indicated that leguminous crops can promote P absorption by neighboring gramineous crops. In this study, we isolated and screened the phosphate‐solubilizing bacteria (PSB) from soybean rhizosphere under a maize–soybean intercropping system in Southwest China, and nine PSBs with high P‐solubilizing ability were identified. RESULTS 16S rDNA sequencing and phylogenetic analysis showed that these PSBs belong mainly to Bacillus and Pseudomonas. The phosphate solubility of Bacillus aryabhattai B8W22 reached 388.62 μg mL−1. High‐performance liquid chromatographic analysis showed that each strain could secrete a large quantity of organic acids, including oxalic acid, malonic acid, citric acid and succinic acid. In addition, all strains produced indole acetic acid (IAA) and siderophores that could promote plant growth. Seed germination experiments testified that PSBs isolated in this study have an innate ability to promote plant growth. The plant culture pot experiment further illustrated that soil acid phosphatase (ACP) activity and available P content, as well as plant P uptake, increased significantly with PSBs inoculation. CONCLUSION PSBs from the rhizosphere soil of intercropped soybean could secrete organic acids that increase the solubilization of unavailable P, improve soil ACP activity and P availability, and produce IAA and siderophores that promote maize seed germination and seedling growth. Our findings indicate the PSBs from soybean rhizosphere have significant potential to reduce the application of chemical phosphate fertilizers and to promote sustainable agricultural development. © 2021 Society of Chemical Industry.

Novosphingobium kaempferiae sp. nov., a phosphate-solubilizing bacterium isolated from stem of Kaempferia marginata Carey

“…silvae KACC 21283 T (56.43 μg ml −1 ) and N. naphthalenivorans JCM 13951 T (17.36 μg ml −1 ) (); similar results have been reported previously [9, 45, 48, 49]. Therefore, this novel strain Sx8-5 T will be useful as a bioinoculant or biofertilizer in enhancing phosphorus for plant growth and development.…”

Changes in phosphorus mobilization and community assembly of bacterial and fungal communities in rice rhizosphere under phosphate deficiency

“…In addition, some P-mobilizing strains are also plant growthpromoting rhizobacteria (PGPR), which promote plant growth Frontiers in Microbiology 09 frontiersin.org in many ways, such through producing phytohormones and controlling phytopathogens. Phosphate solubilization by rhizosphere microorganisms was found to be coupled with production of phytohormones, such as indole-3-acetic acid (IAA) and gibberellic acid (GA; Adhya et al, 2015;Kalayu, 2019;Song et al, 2022). Thus, plants may prefer to recruit these PGPR rather than those that only have P-mobilization capacity.…”

Maize-soybean relay strip intercropping reshapes the rhizosphere bacterial community and recruits beneficial bacteria to suppress Fusarium root rot of soybean

“…Moreover, the rich plant diversity not only has beneficial effects on the richness and activity of soil microorganisms but also enhances plant resistance to pathogens by recruiting beneficial bacterial communities (Mendes et al, 2011 ; Latz et al, 2012 ). When these beneficial microorganisms successfully colonize the plant rhizosphere, on the one hand, they can directly promote plant growth through bio-fertilization (Song et al, 2021 , 2022 ), stimulation of root growth (Glick, 1995 ; Glick et al, 1995 ; Dhar Purkayastha et al, 2018 ), rhizo-remediation (Lugtenberg and Kamilova, 2009 ), and plant stress control (Trivedi et al, 2020 ), and on the other hand, rhizosphere microbes can also indirectly protect plant health by antibiosis (Gu et al, 2020 ; Shalev et al, 2022 ), induction of systemic resistance (Pieterse et al, 2014 ; Lee et al, 2021 ), and competition for nutrients and niches (Barber and Elde, 2015 ; Humphrey et al, 2020 ; Shalev et al, 2022 ). A lot of evidence show that Pseudomonas sp., Streptomyces sp., Bacillus sp., Microbacillus sp., and Flavobacterium sp.…”