title: Imbalance in expression of hop (Humulus lupulus) chalcone synthase H1 and its regulators during hop stunt viroid pathogenesis.
abstract: Viroid-derived small RNAs generated during hop stunt viroid (HSVd) pathogenesis may induce the symptoms found in the hop cultivar "Admiral", including observed shifts in phenylpropanoid metabolites and changes in petiole coloration. Using quantitative RT-PCR, we examined hop lupulin gland-specific genes that have been shown to be involved in phenylpropanoid metabolism, for altered expression in response to infection with two HSVd isolates, HSVd-g and CPFVd. Most notably, the expression of a gene encoding a key enzyme for phenylpropanoid synthesis, naringenin-chalcone synthase H1 (chs_H1), decreased up to 40-fold in infected samples. In addition, a marked decrease in the expression of HlbHLH2 and an increase in the expression of HlMyb3 were observed. These two genes encode transcription factors that form a ternary complex with HlWDR1 for chs_H1 promoter activation. In a transient expression assay, a decrease in the ternary complex potential to activate the chs_H1 promoter was observed upon the decrease of HlbHLH2 expression. In addition, targeting of the chs_H1 transcript by vd-sRNAs may contribute to these expression changes. Our data show that HSVd infection causes a significant imbalance in the expression of phenylpropanoid metabolite-affecting genes via a complex mechanism, possibly involving regulatory disorders and direct targeting by vd-sRNA.
authors: University of South Bohemia, Faculty of Science, Branišovská 31, 370 05 České Budějovice, Czech Republic. zoltan@umbr.cas.cz
authors: Zoltán
authors: Z
authors: Füssy
authors: Josef
authors: J
authors: Patzak
authors: Jan
authors: J
authors: Stehlík
authors: Jaroslav
authors: J
authors: Matoušek
mesh_terms: D000217:Acyltransferases / Q000235:genetics* / Q000378:metabolism; D019295:Computational Biology; D015536:Down-Regulation; D015870:Gene Expression; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D027582:Humulus / Q000201:enzymology* / Q000235:genetics / Q000821:virology; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000821:virology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000201:enzymology / Q000235:genetics / Q000821:virology; D020005:Propanols / Q000378:metabolism*; D034622:RNA Interference; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D018749:RNA, Plant / Q000737:chemistry / Q000235:genetics; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation; D014772:Viroids / Q000472:pathogenicity / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D020005:Propanols; D012333:RNA, Messenger; D018749:RNA, Plant; D012367:RNA, Viral; D014157:Transcription Factors; C439395:1-phenylpropanol; D000217:Acyltransferases; C020141:flavanone synthetase