Multiple plant hormone catabolism activities: an adaptation to a plant-associated lifestyle by Achromobacter spp.

Elaborating the plant hormone catabolic activities of bacteria is important for developing a detailed understanding of plant-microbe interactions. In this work, the plant hormone catabolic and plant growth promotion activities of Achromobacter xylosoxidans SOLR10 and A. insolitus AB2 are described. The genome sequences of these strains were obtained and analysed in detail, revealing the genetic mechanisms behind its multiple plant hormone catabolism abilities. Achromobacter strains catabolized indoleacetic acid (IAA) and phenylacetic acid (PAA) (auxins); salicylic acid (SA) and its precursor, benzoic acid (BA); and the ethylene precursor 1-aminocyclopropane-1-carboxylate (ACC). The inoculation of cucumber plants resulted in increased plant growth and development, indicating the beneficial properties of SOLR10 and AB2 strains. Genomic analysis demonstrated the presence of IAA, PAA and BA degradation gene clusters, as well as the nag gene cluster (SA catabolism) and the acdS gene (ACC deaminase), in the genomes of strains SOLR10 and AB2. Additionally, detailed analysis revealed that plant hormone catabolism genes were commonly detected in the Achromobacter genus but were mostly absent in the Bordetella genus, consistent with the notion that Achromobacter evolved in soils in close association with its plant hosts.

Automated summary

The study found that Achromobacter xylosoxidans SOLR10 and A. insolitus AB2 have plant hormone catabolic and plant growth promotion activities, and conducted genome analysis to reveal the genetic mechanisms behind their multiple plant hormone catabolism abilities. The inoculation of cucumber plants with these strains resulted in increased plant growth and development, indicating their beneficial properties. Additionally, genomic analysis showed the presence of various plant hormone catabolism gene clusters in the genomes of these strains, suggesting their role in plant-microbe interactions.