Distribution, characterization, and evolution of heavy metal resistance genes and Tn7-like associated heavy metal resistance Gene Island of Burkholderia

Yanhong Lan; Meijia Liu; Yao Song; Yu Cao; Fosheng Li; Dening Luo; Dairong Qiao

doi:10.3389/fmicb.2023.1252127

Distribution, characterization, and evolution of heavy metal resistance genes and Tn7-like associated heavy metal resistance Gene Island of Burkholderia

Front Microbiol. 2023 Nov 23:14:1252127. doi: 10.3389/fmicb.2023.1252127. eCollection 2023.

Authors

Yanhong Lan¹, Meijia Liu¹, Yao Song¹, Yu Cao¹, Fosheng Li¹, Dening Luo², Dairong Qiao¹

Affiliations

¹ Microbiology and Metabolic Engineering Key Laboratory of Sichuan Province, Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
² Chengdu University of Information Technology, Chengdu, China.

Abstract

Introduction: Burkholderia is a rod-shaped aerobic Gram-negative bacteria with considerable genetic and metabolic diversity, which can beused for bioremediation and production applications, and has great biotechnology potential. However, there are few studies on the heavy metal resistance of the Burkholderia genus.

Methods: In this paper, the distribution, characteristics and evolution of heavy metal resistance genes in Burkholderia and the gene island of Tn7-like transposable element associated with heavy metal resistance genes in Burkholderia were studied by comparative genomic method based on the characteristics of heavy metal resistance.

Results and discussion: The classification status of some species of the Burkholderia genus was improved, and it was found that Burkholderia dabaoshanensis and Burkholderia novacaledonica do not belong to the Burkholderia genus.Secondly, comparative genomics studies and pan-genome analysis found that the core genome of Burkholderia has alarger proportion of heavy metal resistance genes and a greater variety of heavy metalresistance genes than the subsidiary genome and strain specific genes. Heavy metal resistance genes are mostly distributed in the genome in the form of various gene clusters (for example, mer clusters, ars clusters, czc/cusABC clusters). At the same time, transposase, recombinase, integrase and other genes were foundupstream and downstream of heavy metal gene clusters, indicating that heavy metal resistance genes may beobtained through horizontal transfer. The analysis of natural selection pressure of heavy metal resistance genes showed that heavy metal resistance genes experienced strong purification selection under purification selection pressure in the genome.The Tn7 like transposable element of Burkholderia was associated with the heavy metal resistance gene island, and there were a large number of Tn7 transposable element insertion events in genomes. At the same time, BGI metal gene islands related to heavy metal resistance genes of Tn7 like transposable element were found, and these gene islands were only distributed in Burkholderia cepacia, Burkholderia polyvora, and Burkholderia contaminant.

Keywords: Burkholderia; Tn7-like transposon; comparative genome; heavy metal resistance gene; horizontal transfer; pan-genome.

Grants and funding

This work was supported by the National Natural Science Foundation of China (32071479 and 32271535), the Sichuan Provincial S&T Projects, China (Nos. 2022NSFSC0934 and 2023YFG0122).