Insights Into the Ecological Role of Pseudomonas spp. in an Ant-plant Symbiosis

Author(s)

Fukuda, Taise T. H. ^[1] ; Pereira, Camila F. ^[1] ; Melo, Weilan G. P. ^[1] ; Menegatti, Carla ^[1] ; Andrade, Paulo H. M. ^[2] ; Groppo, Milton ^[3] ; Lacava, Paulo T. ^[2] ; Currie, Cameron R. ^[4] ; Pupo, Monica T. ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Pharmaceut Sci Ribeirao Preto, Ribeirao Preto - Brazil

^[2] Univ Fed Sao Carlos, Ctr Biol & Hlth Sci, Dept Morphol & Pathol, Lab Microbiol & Biomol, Sao Carlos - Brazil

^[3] Univ Sao Paulo, Fac Philosophy Sci & Letters Ribeirao Preto, Dept Biol, Lab Plant Systemat, Ribeirao Preto - Brazil

^[4] Univ Wisconsin, Dept Bacteriol, Madison, WI 53706 - USA

• Document type: Journal article
• Source: FRONTIERS IN MICROBIOLOGY; v. 12, FEB 1 2021.
• Web of Science Citations: 0

Abstract

In the myrmecophytic mutualistic relationship between Azteca ants and Cecropia plants both species receive protection and exchange nutrients. The presence of microorganisms in this symbiotic system has been reported, and the symbiotic role of some fungi involved in the myrmecophytic interactions has been described. In this work we focus on bacteria within this mutualism, conducting isolations and screening for antimicrobial activities, genome sequencing, and biochemical characterization. We show that Pantoea, Rhizobium, Methylobacterium, Streptomyces and Pseudomonas are the most common cultivable genera of bacteria. Interestingly, Pseudomonas spp. isolates showed potent activity against 83% of the pathogens tested in our antimicrobial activity assays, including a phytopathogenic fungus isolated from Cecropia samples. Given the predicted nitrogen limitations associated with the fungal patches within this myrmecophyte, we performed nitrogen fixation analyses on the bacterial isolates within the Proteobacteria and show the potential for nitrogen fixation in Pseudomonas strains. The genome of one Pseudomonas strain was sequenced and analyzed. The gene cluster involved in the biosynthesis of cyclic lipodepsipeptides (CLPs) was identified, and we found mutations that may be related to the loss of function in the dual epimerization/condensation domains. The compound was isolated, and its structure was determined, corresponding to the antifungal viscosinamide. Our findings of diazotrophy and production of viscosinamide in multiple Pseudomonas isolates suggests that this bacterial genus may play an important role in the Cecropia-Azteca symbiosis. (AU)

• FAPESP's process: 15/01001-6 - Discovering bacterial symbionts diversity associated with ants in different Brazilian biomes
• Grantee: Weilan Gomes da Paixão Melo
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 16/15576-3 - Natural products involved in symbiosis between actinobacteria and social insects
• Grantee: Carla Menegatti
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/50954-0 - Novel therapeutic agents from the bacterial symbionts of Brazilian invertebrates
• Grantee: Mônica Tallarico Pupo
• Support type: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 19/19099-3 - Genomic analysis of antibiotic-producing Pseudonocardia associated with Attini ants
• Grantee: Weilan Gomes da Paixão Melo
• Support type: Scholarships in Brazil - Technical Training Program - Technical Training
• FAPESP's process: 16/26230-0 - Cecropia-Azteca symbiosis study: interspecific microbial interactions as elicitors of antimicrobial activity
• Grantee: Camila Fiori Pereira
• Support type: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 15/26349-5 - Chemical and ecological study of microorganisms associated with the symbiosis Cecropia-Azteca
• Grantee: Taise Tomie Hebihara Fukuda
• Support type: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 17/17305-0 - Understanding the bacterial symbiosis in Cecropia-Azteca system using chemical and genetic tools
• Grantee: Taise Tomie Hebihara Fukuda
• Support type: Scholarships abroad - Research Internship - Doctorate (Direct)