AUTHOR=Sefer Özlem , Özsoy Esma , Yörük Emre , Özkale Evrim 

TITLE=Determining the biocontrol capacities of Trichoderma spp. originating from Turkey on Fusarium culmorum by transcriptional and antagonistic analyses

JOURNAL=Frontiers in Fungal Biology

VOLUME=Volume 4 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/fungal-biology/articles/10.3389/ffunb.2023.1278525

DOI=10.3389/ffunb.2023.1278525

ISSN=2673-6128

ABSTRACT=In this study, aiming to investigate potential fungal biocontrol agents for Fusarium culmorum, several isolates of Trichoderma spp were evaluated for their antagonistic effects by the means of transcriptional analyses. At first, 21 monosporic Trichoderma spp. isolates were obtained from natural wood debris and wood area soils in Manisa/Turkey. Trichoderma spp. isolates were identified belonging to four different species as T. atroviride, T. harzianum, T. koningii, and T. brevicompactum by tef1-α sequencing. As following, linear growth rates (LGR) for those were calculated in the range between 13.22±0.71 mm/day (T. atroviride TR2) and 25.06±1.45 mm/day (T. harzianum K30). Inter-simple sequence repeats (ISSR) genotyping validated the tef1-α sequencing results by presenting two sub-clusters in the dendrogram. Genetically most similar (TR1 & TR2; 97.77 %) and dissimilar (K9 & K17; 40.40 %) individuals belonging to the same and different species, respectively. Dual sandwich culture tests (which is useful for antagonism studies) revealed that T. harzianum K21 (the least suppressive) and T. brevicompactum K26 (the most suppressive) isolates suppressed F. culmorum with the growth rates as 3% and 46%, respectively. Expressions of genes previously associated with mycoparasitism-plant protection-secondary metabolism (nag1, tgf-1 and tmk-1) were tested by quantitative real-time polymerase chain reaction (qRT-PCR), in both those isolates. While there were no significant differences (p>0.05) in expression that were present in K21 isolate, those three genes were up regulated with fold change values of 2.69±0.26 (p<0.001), 2.23±0.16 (p<0.001), and 5.38±2.01 (p<0.05) in K26 meaning that the presence of significant alteration in physiological processes in fungus. Also, mycoparasitism potential of its was tested on Triticum aestivum L. cv Basribey in planta, infected with F. culmorum FcUK99 strain. Results of the trials including specific plant growth parameters (weight or length of plantlets), highly confirmed the mycoparasitic potential of the isolate. It can be concluded that (i) nag1, tgf-1, and tmk-1 genes could be approved as reliable markers for evaluation of BCA capacities of Trichoderma spp. and (ii) T. brevicompactum K26 strain can be suggested as promising candidate for combating in F. culmorum diseases following the necessary procedures to ensure it is non-hazardous and safe.