title: Harnessing anthocyanin-rich fruit: a visible reporter for tracing virus-induced gene silencing in pepper fruit.
abstract: BACKGROUND
  Virus-induced gene silencing (VIGS) has become a powerful tool for post-genomic technology in plant species. This is important, especially in select plants, such as the pepper plant, that are recalcitrant toAgrobacterium-mediated transformation. Although VIGS in plants has been widely employed as a powerful tool for functional genomics, scattering phenotypic effects by uneven gene silencing has been implemented in order to overcome challenges in experiments with fruit tissues.
  
  
  RESULTS
  We improved the VIGS system based on the tobacco rattle virus (TRV) containing theAn2MYB transcription factor, which is the genetic determinant of purple colored- or anthocyanin-rich pepper. Silencing of endogenousAn2in the anthocyanin-rich pepper with the modified TRV vector for ligation-independent cloning (LIC) lacked purple pigment in its leaves, flowers, and fruits. Infection with TRV-LIC containing a tandem construct ofAn2andphytoene desaturase(PDS) resulted in a typical photobleaching event in leaves without the purple pigment, whereas silencing ofPDSled to the presence of photobleached and purple-colored leaves. Cosilencing of endogenousAn2andcapsaicin synthasein fruits resulted in decreased levels of capsaicin and dihydrocapsaicin as assessed by high performance liquid chromatography analysis coupled with the absence of the purple pigment in fruits.
  
  
  CONCLUSIONS
  VIGS with tandem constructs harboringAn2as a visible reporter in anthocyanin-rich pepper plants can facilitate the application of functional genomics in the study of metabolic pathways and fruit biology.
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826 Korea.
authors.forename: Jihyun
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826 Korea ; Department of Genetics, University of Georgia, Athens, GA 30602-7223 USA.
authors.forename: Minkyu
authors.initials: M
authors.lastname: Park
authors.affiliation: Department of Horticultural Science, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566 Korea.
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Jeong
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826 Korea ; Department of Horticultural Science, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566 Korea.
authors.forename: Je Min
authors.identifier: 0000-0002-0446-1336
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, College of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826 Korea ; Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, Korea.
authors.forename: Doil
authors.initials: D
authors.lastname: Choi
keywords: An2; Anthocyanin; Capsaicinoid; Pepper; Reporter system; TRV; VIGS