Bacterial volatile organic compounds induce adverse ultrastructural changes and DNA damage to the sugarcane pathogenic fungus Thielaviopsis ethacetica

Author(s):Show less -

Anna Freitas, Carla Sant ^{[1, 2]} ; Maciel, Lucas Ferreira ^[1] ; Correa dos Santos, Renato Augusto ^{[3, 2]} ; Menezes Medeiro Costa, Ohanna Maria ^[4] ; Barbosa Maia, Francisco Carlos ^[4] ; Rabelo, Renata Santos ^[4] ; Junqueira Franco, Henrique Coutinho ^[5] ; Alves, Eduardo ^[6] ; Consonni, Silvio Roberto ^[7] ; Freitas, Raul Oliveira ^[4] ; Persinoti, Gabriela Felix ^[1] ; de Castro Oliveira, Juliana Velasco ^{[1, 2]}

Affiliation

^[1] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Biorenewable Natl Lab LNBR, Campinas, SP - Brazil

^[2] Univ Campinas UNICAMP, Genet & Mol Biol Grad Program, Campinas, SP - Brazil

^[3] Univ Sao Paulo, Sch Pharmaceut Sci Ribeirao Preto, Ribeirao Preto, SP - Brazil

^[4] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Synchrotron Light Lab LNLS, Campinas, SP - Brazil

^[5] Cropman Agr Innovat, Campinas, SP - Brazil

^[6] Fed Univ Lavras UFLA, Plant Pathol Dept, Lab Electron Microscopy & Ultrastruct Anal, Lavras, MG - Brazil

^[7] Univ Campinas UNICAMP, Inst Biol, Dept Biochem & Tissue Biol, Campinas, SP - Brazil

• Document type: Journal article
• Source: ENVIRONMENTAL MICROBIOLOGY; JAN 2022.
• Web of Science Citations: 0

Abstract

Due to an increasing demand for sustainable agricultural practices, the adoption of microbial volatile organic compounds (VOCs) as antagonists against phytopathogens has emerged as an eco-friendly alternative to the use of agrochemicals. Here, we identified three Pseudomonas strains that were able to inhibit, in vitro, up to 80% of mycelial growth of the phytopathogenic fungus Thielaviopsis ethacetica, the causal agent of pineapple sett rot disease in sugarcane. Using GC/MS, we found that these bacteria produced 62 different VOCs, and further functional validation revealed compounds with high antagonistic activity to T. ethacetica. Transcriptomic analysis of the fungal response to VOCs indicated that these metabolites downregulated genes related to fungal central metabolism, such as those involved in carbohydrate metabolism. Interestingly, genes related to the DNA damage response were upregulated, and micro-FTIR analysis corroborated our hypothesis that VOCs triggered DNA damage. Electron microscopy analysis showed critical morphological changes in mycelia treated with VOCs. Altogether, these results indicated that VOCs hampered fungal growth and could lead to cell death. This study represents the first demonstration of the molecular mechanisms involved in the antagonism of sugarcane phytopathogens by VOCs and reinforces that VOCs can be a sustainable alternative for use in phytopathogen biocontrol. (AU)

• FAPESP's process: 17/20521-6 - HS-GC/MS platform for the analysis of plant growth promoter volatiles
• Grantee: Juliana Velasco de Castro Oliveira
• Support Opportunities: Research Grants - Research Partnership for Technological Innovation - PITE
• FAPESP's process: 17/24395-5 - Identification and use of bacterial volatiles against sugarcane pathogens
• Grantee: Juliana Velasco de Castro Oliveira
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants