Transcription factors (TFs) play a major role in controlling gene expression by intricately regulating diverse biological processes such as growth and development, the response to external stimuli and the activation of defense responses. The systematic identification and classification of TF genes are essential to gain insight into their evolutionary history, biological roles, and regulatory networks. In this study, we performed a global mining and characterization of hop TFs and their involvement in Citrus bark cracking viroid CBCVd infection by employing a digital gene expression analysis. Our systematic analysis resulted in the identification of a total of 3,818 putative hop TFs that were classified into 99 families based on their conserved domains. A phylogenetic analysis classified the hop TFs into several subgroups based on a phylogenetic comparison with reference TF proteins from Arabidopsis thaliana providing glimpses of their evolutionary history. Members of the same subfamily and subgroup shared conserved motif compositions. The putative functions of the CBCVd-responsive hop TFs were predicted using their orthologous counterparts in A. thaliana. The analysis of the expression profiling of the CBCVd-responsive hop TFs revealed a massive differential modulation, and the expression of the selected TFs was validated using qRT-PCR. Together, the comprehensive integrated analysis in this study provides better insights into the TF regulatory networks associated with CBCVd infections in the hop, and also offers candidate TF genes for improving the resistance in hop against viroids.

• MeSH
• Phylogeny MeSH
• Humulus classification   genetics   immunology   virology   MeSH
• Plant Bark immunology   virology   MeSH
• Plant Diseases genetics   immunology   virology   MeSH
• Plant Proteins genetics   immunology   MeSH
• Gene Expression Profiling MeSH
• Transcription Factors genetics   immunology   MeSH
• Viroids genetics   physiology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Wild hops (Humulus lupulus L.) are potential new germplasms to expand the variability of genetic resources for hop breeding. We evaluated Canadian (62 plants) and Caucasian (58 plants) wild hops by their chemical characteristics and with molecular genetic analyses using sequence-tagged site and simple sequence repeat markers, in comparison with European (104 plants) and North American (27 plants) wild hops. The contents of alpha and beta acids varied from 0.36% to 5.11% and from 0.43% to 6.66% in Canadian wild hops, and from 0.85% to 3.65% and from 1.22% to 4.81% in Caucasian wild hops, respectively. The contents of cohumulone and colupulone distinctly differed between European and North American wild hops: the cohumulone level in alpha acids was in the range 46.1%-68.4% among North American wild hops and in the range 13.6%-30.6% among European wild hops. The high content of myrcene and the low contents of humulene, farnesene, and selinenes were typical for wild hops from Canada, in contrast to wild hops from the Caucasus region. We compared the chemical characteristics with molecular genetic data. Chemical characteristics differentiated wild hops into North American and Eurasian groups. Molecular genetic analysis was able to separate Caucasian wild hops from European wild hops. We proved a hop phylogeny by means of wide molecular analysis.

• MeSH
• Cyclohexanones metabolism   MeSH
• Phylogeny MeSH
• Humulus classification   genetics   metabolism   MeSH
• Minisatellite Repeats genetics   MeSH
• Sequence Tagged Sites MeSH
• Polymorphism, Genetic genetics   MeSH
• Cytochrome P-450 Enzyme System metabolism   MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Geographicals
• Canada MeSH
• Russia MeSH