Diversity, structure, and composition of plant growth-promoting bacteria in soil from Brazilian Cerrado

Abstract

Plant growth-promoting bacteria (PGPB) can enhance plant growth and protect plants from biotic and abiotic stresses, and their presence in soils is important to improve plant productivity. In this study, we evaluated the diversity, structure, and composition of the PGPB community in Brazilian Cerrado with different types of physiognomies (Campo Graminoide, Cerrado stricto sensu, and Cerradao). There were no differences between the diversity and richness of the PGPB community among the three types of physiognomies. However, each physiognomy showed different composition and structure of the PGPB community that was driven by environmental conditions, mainly soil temperature, pH, moisture, and macronutrients. The PGPB community was dominated by Bacillus (36.2%), Alicyclobacillus (22.1%), Mycobacterium (12.2%), Paenibacillus (9.1%), Burkholderia (7%), Streptomyces (5.7%), Saccharopolyspora (1.7%), and Brevibacillus (1.4%) and Campo Graminoide presented a higher abundance of most PGPB genera. In addition, the interactions between PGPB were more complex in Cerradao (1411 edges) than other physiognomies. This study also showed that the PGPB community is well embedded within the whole bacterial community, revealing that these bacterial species are important drivers of the overall bacterial community in these soils. The findings of this study expand the knowledge about the PGPB community in Cerrado and add important information that can contribute to the further prospection of these bacterial species.