Investigating the Modes of Action of the Antimicrobial Chalcones BC1 and T9A
Luana G. Morão,
André S. G. Lorenzoni,
Parichita Chakraborty,
Gabriela M. Ayusso,
Lucia B. Cavalca,
Mariana B. Santos,
Beatriz C. Marques,
Guilherme Dilarri,
Caio Zamuner,
Luis O. Regasini,
Henrique Ferreira,
Dirk-Jan Scheffers
Affiliations
Luana G. Morão
Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista, 130506-900 SP Rio Claro, Brazil
André S. G. Lorenzoni
Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
Parichita Chakraborty
Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
Gabriela M. Ayusso
Departamento de Química e Ciências Ambientais, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, 15054-000 SP São José do Rio Preto, Brazil
Lucia B. Cavalca
Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
Mariana B. Santos
Departamento de Química e Ciências Ambientais, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, 15054-000 SP São José do Rio Preto, Brazil
Beatriz C. Marques
Departamento de Química e Ciências Ambientais, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, 15054-000 SP São José do Rio Preto, Brazil
Guilherme Dilarri
Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista, 130506-900 SP Rio Claro, Brazil
Caio Zamuner
Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista, 130506-900 SP Rio Claro, Brazil
Luis O. Regasini
Departamento de Química e Ciências Ambientais, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, 15054-000 SP São José do Rio Preto, Brazil
Henrique Ferreira
Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista, 130506-900 SP Rio Claro, Brazil
Dirk-Jan Scheffers
Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands
Xanthomonas citri subsp. citri (X. citri) is an important phytopathogen and causes Asiatic Citrus Canker (ACC). To control ACC, copper sprays are commonly used. As copper is an environmentally damaging heavy metal, new antimicrobials are needed to combat citrus canker. Here, we explored the antimicrobial activity of chalcones, specifically the methoxychalcone BC1 and the hydroxychalcone T9A, against X. citri and the model organism Bacillus subtilis. BC1 and T9A prevented growth of X. citri and B. subtilis in concentrations varying from 20 µg/mL to 40 µg/mL. BC1 and T9A decreased incorporation of radiolabeled precursors of DNA, RNA, protein, and peptidoglycan in X. citri and B. subtilis. Both compounds mildly affected respiratory activity in X. citri, but T9A strongly decreased respiratory activity in B. subtilis. In line with that finding, intracellular ATP decreased strongly in B. subtilis upon T9A treatment, whereas BC1 increased intracellular ATP. In X. citri, both compounds resulted in a decrease in intracellular ATP. Cell division seems not to be affected in X. citri, and, although in B. subtilis the formation of FtsZ-rings is affected, a FtsZ GTPase activity assay suggests that this is an indirect effect. The chalcones studied here represent a sustainable alternative to copper for the control of ACC, and further studies are ongoing to elucidate their precise modes of action.
