Dahlia variabilis cultivar 'Seattle' as a model plant for anthochlor biosynthesis

Author(s)
Benjamin Walliser, Calin Rares Lucaciu, Christian Molitor, Silvija Marinovic, Daria Agata Nitarska, Didem Aktaş, Thomas Rattei, Ioannis Kampatsikas, Karl Stich, Christian Haselmair-Gosch, Heidi Halbwirth
Abstract

We investigated the bi-colored dahlia cultivar 'Seattle', which exhibits bright yellow petals with white tips, for its potential use as a model system for studies of the anthochlor biosynthesis. The yellow base contained high amounts of the 6'-deoxychalcones and the structurally related 4-deoxyaurones, as well as flavones. In contrast, only traces of anthochlors and flavones were detected in the white tips. No anthocyanins, flavonols, flavanones or dihydroflavonols were found in the petals. Gene expression studies indicated that the absence of anthocyanins in the petals is caused by a lack of flavanone 3-hydroxylase (FHT) expression, which is accompanied by a lack of expression of the bHLH transcription factor IVS. Expression of other genes involved in anthocyanidin biosynthesis such as dihydroflavonol 4-reductase (DFR) and anthocyanidin synthase (ANS) was not affected. The yellow and white petal parts showed significant differences in the expression of chalcone synthase 2 (CHS2), which is sufficient to explain the absence of yellow pigments in the white tips. Transcriptomes of both petal parts were de novo assembled and three candidate genes for chalcone reductase (CHR) were identified. None of them showed a significantly higher expression in the yellow base compared to the white tips. In summary, it was shown that the bicolouration is most likely caused by a bottleneck in chalcone formation in the white tip. The relative prevalence of flavones compared to the anthochlors in the white tips could be an indication for the presence of a so far unknown differentially expressed CHR.

Organisation(s)
Department of Microbiology and Ecosystem Science
External organisation(s)
Technische Universität Wien
Journal
Plant Physiology and Biochemistry
Volume
159
Pages
193-201
No. of pages
9
ISSN
0981-9428
DOI
https://doi.org/10.1016/j.plaphy.2020.12.016
Publication date
12-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
106005 Bioinformatics, 106026 Ecosystem research
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/dahlia-variabilis-cultivar-seattle-as-a-model-plant-for-anthochlor-biosynthesis(2b090e11-2d1b-42e4-a14c-d972d71573e2).html