|Rodriguez Estrada, Alma|
|Kistler, H - Corby|
Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2012
Publication Date: 3/9/2012
Citation: Jonkers, W., Rodriguez Estrada, A.E., Breakspear, A., May, G., Kistler, H.C. 2012. The metabolome and transcriptome of the interaction between Ustilago maydis and Fusarium verticillioides in vitro. Applied and Environmental Microbiology. 78(10):3656-3667. Interpretive Summary: Plants interact with fungi in ways in the natural environment. Some fungi may cause plant diseases or harmlessly colonize plant stems, leaves or roots while others decompose dead and dying plants. The goal of this study was to understand how different fungi that infect the same plant may interact and to determine the outcome of this interaction. Two fungi that infect corn leaves and that are capable of causing disease were found to be antagonistic to each other when grown together in culture. One fungus in fact can completely inhibit the growth of the other and cause changes in gene expression and the concentration of small metabolites which may ultimately influence the growth of the corn plant. This study thus establishes that complex interactions between these fungi may ultimately determine the outcome of plant infection and plant health. This information will be helpful to plant improvement specialists who are working to develop plants resistant to these fungi or for developing novel strategies for disease control.
Technical Abstract: The metabolome and transcriptome of the maize-infecting fungi Ustilago maydis and Fusarium verticillioides were analyzed as the two fungi interact. Both fungi were grown for seven days in liquid medium alone or together in order to study how this interaction changes their metabolomic and transcriptomic profiles. When grown together, decreased biomass accumulation occurs for both fungi after an initial acceleration of growth compared to the biomass changes that occur when grown alone. The biomass of U. maydis declined most severely over time and may be attributed to the action of F. verticillioides, which secretes toxic secondary metabolites and expresses genes encoding adhesive and cell wall degrading proteins at higher levels compared to when grown alone. U. maydis responds to co-cultivation by expressing siderophore biosynthetic genes and more highly expresses genes potentially involved in toxin biosynthesis. Also, higher expression was noted for clustered genes encoding secreted proteins that are unique to U. maydis and that may play a role during colonization of maize. Conversely, decreased gene expression was seen for U. maydis genes encoding the synthesis of ustilagic acid, mannosylerythritol D and another uncharacterized metabolite. Ultimately, U. maydis is unable to react efficiently to the toxic response of F. verticillioides and proportionally loses more biomass. This in vitro study clarifies potential mechanisms of antagonism between these two fungi that also may occur in the soil or in maize, niches for both fungi where they likely interact in nature.