Baqiyatallah University of Medical Sciences Journal of Applied Biotechnology Reports 2322-1186 7 4 2020 12 01 Changes in Cytochrome b Gene Expression in Cochliobolus sativus Induced by Triadimefon, a Triazole Fungicide 198 202 120166 10.30491/jabr.2020.230682.1223 EN Mohammed Imad Eddin Arabi Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria 0000-0001-7770-061X Huda Alek Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria Eyad Al-Shehadah Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria Mohammed Jawhar Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria Journal Article 2020 05 10 <strong>Introduction:</strong> Spot blotch, caused by <em>Cochliobolus sativus</em>, is most effectively managed using fungicide applications, including triadimefon (TDM) a triazole compound. <em>C. sativus </em>posses a great concern as it might develop resistance against fungicides like TDM due to its high genetic variability, short life cycle, and abundant inoculum production. Therefore, to better understand the mechanisms of TDM resistance initiated by <em>C. sativus</em>, changes in cytochrome <em>b</em> (<em>cytb</em>) gene in virulent and avirulent pathotypes were evaluated at early time points of TDM treatments.<br /> <strong>Materials and Methods: </strong><em>C. sativus</em> sensitivity to TDM was determined by measuring the radial growth of each pathotype on PDA plates. Additionally, RNA was isolated from mycelia of each pathotype at 24, 48, 72 and 96 hours post fungicide treatments and used for cDNA synthesis. <em>Cytb </em>was verified using quantitative reverse transcriptase PCR (qRT-PCR).<br /> <strong>Results: </strong>Data showed that the maximum mycelial growth inhibition by 50% (EC50) for both pathotypes was recorded 48h at 0.25 µg/ml TDM treatment. The qRT-PCR revealed that <em>cytb</em> expression increased in both virulent and avirulent pathotypes at 24h post TDM treatments in comparison with non-treated controls. The most outstanding differences in <em>cytb </em>expression were7.69 and 2.88-fold in the virulent and avirulent pathotypes, respectively, 48h of 0.25 µg/mlTDM treatment.<br /> <strong>Conclusions: </strong>According to findings, it is possible to propose that <em>cytb </em>gene might play a role in signaling events during <em>C. sativus </em>exposure to commercial triazole fungicide.<br /> <br /><br /><br /><br /> https://www.biotechrep.ir/article_120166_8f924af61e89784cca5a2a632910b212.pdf