This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 150/3/1122    most recent pp.109.139006v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Google Scholar Articles by Orzaez, D. Articles by Granell, A. PubMed PubMed Citation Articles by Orzaez, D. Articles by Granell, A. Agricola Articles by Orzaez, D. Articles by Granell, A. Related Collections Vector Systems for Plant Research and Biotechnology

BREAKTHROUGH TECHNOLOGIES

A Visual Reporter System for Virus-Induced Gene Silencing in Tomato Fruit Based on Anthocyanin Accumulation^1,[C],[W]

Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas, Universidad Politécnica de Valencia, 46022 Valencia, Spain (D.O., A.M., S.T., J.P.F.-M., J.L.R., A.F.-d.-C., A.G.); and John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom (E.B., C.M.)

Virus-induced gene silencing (VIGS) is a powerful tool for reverse genetics in tomato (Solanum lycopersicum). However, the irregular distribution of the effects of VIGS hampers the identification and quantification of nonvisual phenotypes. To overcome this limitation, a visually traceable VIGS system was developed for fruit, comprising two elements: (1) a transgenic tomato line (Del/Ros1) expressing Antirrhinum majus Delila and Rosea1 transcription factors under the control of the fruit-specific E8 promoter, showing a purple-fruited, anthocyanin-rich phenotype; and (2) a modified tobacco rattle virus VIGS vector incorporating partial Rosea1 and Delila sequences, which was shown to restore the red-fruited phenotype upon agroinjection in Del/Ros1 plants. Dissection of silenced areas for subsequent chemometric analysis successfully identified the relevant metabolites underlying gene function for three tomato genes, phytoene desaturase, TomloxC, and SlODO1, used for proof of concept. The C-6 aldehydes derived from lipid 13-hydroperoxidation were found to be the volatile compounds most severely affected by TomloxC silencing, whereas geranial and 6-methyl-5-hepten-2-one were identified as the volatiles most severely reduced by phytoene desaturase silencing in ripening fruit. In a third example, silencing of SlODO1, a tomato homolog of the ODORANT1 gene encoding a myb transcription factor, which regulates benzenoid metabolism in petunia (Petunia hybrida) flowers, resulted in a sharp accumulation of benzaldehyde in tomato fruit. Together, these results indicate that fruit VIGS, enhanced by anthocyanin monitoring, can be a powerful tool for reverse genetics in the study of the metabolic networks operating during fruit ripening.

² Present address: Department of Soil, Plant, Environmental, and Animal Production Sciences, University of Naples "Federico II," Via Università, 8055 Portici, NA, Italy.

The authors responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) are: Antonio Granell (agranell{at}ibmcp.upv.es) and Cathie Martin (cathie.martin{at}bbsrc.ac.uk).

^[C] Some figures in this article are displayed in color online but in black and white in the print edition.

^[W] The online version of this article contains Web-only data.

www.plantphysiol.org/cgi/doi/10.1104/pp.109.139006

^* Corresponding author; e-mail agranell{at}ibmcp.upv.es.

Received March 26, 2009; accepted May 4, 2009; published May 8, 2009.