ORIGINAL ARTICLE Transcriptomic effects of Aspergillus alliaceus on Orobanche during its pathogenesis Mehmet Aybeke 1 Received: 22 May 2017 / Accepted: 29 August 2017 Ó Deutsche Phytomedizinische Gesellschaft 2017 Abstract The aim of this study was to investigate the pathogenicity of Aspergillus alliaceus (Aa), a fungal bio- control agent, on Orobanche by transcriptomic tests. For this reason, the expression of several genes was analysed comparatively in the experimental (fungi applied) and control (fungi-free) groups. After fungal infection, the expression of antioxidant enzyme genes SOD (Mn-super- oxide dismutase), CAT (catalase), and SOD2 (Zn-super- oxide dismutase) and the genes GS (Glutamine synthetase), HSP70 (heat-shock protein), and apoptosis [BCL2, BAX, caspase3 (CASP3)], which are related to protein metabo- lism, were investigated in the both groups. In gene expression studies, gene expression of SOD was almost 2.5 times higher in the experimental group than in the control group (fungus-free, intact), while the expression levels of other antioxidant genes (CAT and SOD2) were signifi- cantly reduced. While GS, which is the N and protein metabolism balancer, was found to be relatively low as compared to the control group, however, the level of HSP70 (protein folding, chaperoning) was quite higher than the control. Gene expressions of all apoptotic genes, BAX (=apoptosis suppressive gene), CASP3 and BCL (=apoptosis inducer genes), were significantly lower than control group. All the results found for the control group were determined to be statistically significant. It was con- cluded that during Aa pathogenesis, (1) the increased SOD value was associated with ROS (reactive oxygen species) threats, (2) the fungi disturbed protein synthesis metabo- lism, and finally, (3) the inhibited antioxidant and apoptosis-based pathways compared to the control group. These conclusions were discussed in the light of slow but constantly lethal effects of Aa comparatively to other pathogenic fungus, Fusarium. Keywords Orobanche Á Broomrape Á Gen expression Á Antioxidant Á Apoptosis Á Biocontrol Introduction Orobanche (broomrape) is a well-known root parasitic plant, which causes serious decreases in yield of important crops such as sunflower, potato, rapeseed–mustard, faba bean, lentil, tomatoes, alfalfa, pepper, and tobacco (Anonymous 2011). Different applications have been sug- gested for broomrape control such as crop rotation, soil fumigation, soil solarisation, selection of host seed unin- fected with Orobanche seeds, forward/backward sowing dates of host plants, or genetically resistant host plantings to the Orobanche and herbicide (Goldwasser et al. 2003; Pe ´rez-de-Luque et al. 2005; Eizenberg et al. 2009; Her- shenhorn et al. 2009; Kohlschmid et al. 2009). However, some of these control methods were inconvenient, difficult, and harmful to the environment. For example, the soil fumigation in which several highly volatile compounds like methyl bromide are applied into the soil kills all natural life in the soil including Orobanche and may even bring the end of farmers. It has been revealed that this method causes highly hazardous environmental problems (Shabana et al. 2003), and it has been banned in accordance with the laws of Environmental Protection Agency (EPA) of the federal government of USA. Another method is the biological control of Orobanche by using several fungal pathogens. Several fungal & Mehmet Aybeke mehmetaybeke@gmail.com 1 Department of Biology, Faculty of Science, Trakya University, Balkan Campus, 22030 Edirne, Turkey 123 J Plant Dis Prot DOI 10.1007/s41348-017-0122-8