Efflux Pumps and Multidrug-Resistance in Pyricularia oryzae Triticum Lineage

Widespread resistance to QoIs, DMI and SDHIs fungicides has been reported for Brazilian populations of the wheat blast pathogen Pyricularia oryzae Triticum lineage (PoTl). A pre-existing mechanism not associated with target site mutations indicated DMIs SDHIs, strong indication that PoTl multidrugresistance (MDR). Therefore, main objective this study was test hypothesis SDHI detected in due efflux pump mediated MDR mechanism(s) by characterizing sensitivity antifungal substrates. Four substrates were tested: tolnaftate (TOL), cycloheximide (CHX), rhodamine 6G (RH6G) triphenyltin chloride (TPCL). TPCL RH6G considered most relevant indicators enhanced activity. Among 16 isolates tested, 9 insensitive TPCL, 1 TOL, CHX. The grouped into four distinct multidrug phenotypes (MDRPs) based on combinations Insensitivity or TOL correlated well insensitivity, but resistance. identification multiple MDRP our warrants further research aimed at revealing exact mechanisms pathogen, including pumps overexpression via transcriptomic analyses differentially expressed genes; discovery changes promoter regions transcription factors transporters