title: The "putative" role of transcription factors from HlWRKY family in the regulation of the final steps of prenylflavonid and bitter acids biosynthesis in hop (Humulus lupulus L.).
abstract: Lupulin glands localized in female hop (Humulus lupulus L.) cones are valuable source of bitter acids, essential oils and polyphenols. These compounds are used in brewing industry and are important for biomedical applications. In this study we describe the potential effect of transcription factors from WRKY family in the activation of the final steps of lupulin biosynthesis. In particular, lupulin gland-specific transcription factor HlWRKY1 that shows significant similarity to AtWRKY75, has ability to activate the set of promoters driving key genes of xanthohumol and bitter acids biosynthesis such as chalcone synthase H1, valerophenone synthase, prenyltransferase 1, 1L and 2 and O-methyltransferase-1. When combined with co-factor HlWDR1 and silencing suppressor p19, HlWRKY1 is able to enhance transient expression of gus gene driven by Omt1 and Chs_H1 promoters to significant level as compared to 35S promoter of CaMV in Nicotiana. benthamiana. Transformation of hop with dual Agrobacterium vector bearing HlWRKY1/HlWDR1 led to ectopic overexpression of these transgenes and further activation of lupulin-specific genes expression in hop leaves. It was further showed that (1) HlWRKY1 is endowed with promoter autoactivation; (2) It is regulated by post-transcriptional gene silencing (PTGS) mechanism; (3) It is stimulated by kinase co-expression. Since HlWRKY1 promotes expression of lupulin-specific HlMyb3 gene therefore it can constitute a significant component in hop lupulin regulation network. Putative involvement of HlWRKY1 in the regulation of lupulin biosynthesis may suggest the original physiological function of lupulin components in hop as flower and seed protective compounds.
authors.affiliation: Biology Centre of the Czech Academy of Sciences v.v.i, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic. jmat@umbr.cas.cz.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Matoušek
authors.affiliation: Biology Centre of the Czech Academy of Sciences v.v.i, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Kocábek
authors.affiliation: Hop Research Institute, Co. Ltd., Kadaňská 2525, 438 46, Žatec, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Patzak
authors.affiliation: Biology Centre of the Czech Academy of Sciences v.v.i, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic.
authors.forename: Jindřich
authors.initials: J
authors.lastname: Bříza
authors.affiliation: Biology Centre of the Czech Academy of Sciences v.v.i, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic.|Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
authors.forename: Kristýna
authors.initials: K
authors.lastname: Siglová
authors.affiliation: Biology Centre of the Czech Academy of Sciences v.v.i, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic.
authors.forename: Ajay Kumar
authors.initials: AK
authors.lastname: Mishra
authors.affiliation: Biology Centre of the Czech Academy of Sciences v.v.i, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic.
authors.forename: Ganesh Selvaraj
authors.initials: GS
authors.lastname: Duraisamy
authors.affiliation: Biology Centre of the Czech Academy of Sciences v.v.i, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic.|Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
authors.forename: Anna
authors.initials: A
authors.lastname: Týcová
authors.affiliation: Research Institute, Suntory Global Innovation Center (SIC) Ltd., 1-1-1 Wakayamadai, Shimamoto, Mishima, Osaka, 618-8503, Japan.
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Ono
authors.affiliation: Hop Research Institute, Co. Ltd., Kadaňská 2525, 438 46, Žatec, Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Krofta
mesh_terms: D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing / Q000502:physiology; D027582:Humulus / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D013729:Terpenes; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D013729:Terpenes; D014157:Transcription Factors; C008299:lupulon
keywords: 5′ RNA degradome; Hop transformation; Lupulin biosynthesis; Plant promoter activation; Transcription factors; WRKY oligofamily