QTL mapping and candidate gene research for the phenolic content of fruits and juices prepared from a cider apple progeny

QTL MAPPING AND CANDIDATE GENE RESEARCH FOR THE PHENOLIC

QTL MAPPING AND CANDIDATE GENE RESEARCH FOR THE PHENOLIC

CONTENT OF FRUITS AND JUICES PREPARED FROM A CIDER APPLE PROGENY

CONTENT OF FRUITS AND JUICES PREPARED FROM A CIDER APPLE PROGENY

VERDU C.F.

_{, Guyot S.}

_{, Childebrand N.}

_{, Lasserre-Zuber P.}

_{, Gaillard S.}

_{, Celton J.-M.}

_{, Troggio M.}

_{, Guilet D.}

_{and Laurens F.}

4207 QUASAV, 49045 Angers, France, 3_{INRA, UR117 Recherches Cidricoles et Biotransformation des Fruits et Légumes, 35653 Le Rheu, France,} 4_{IASMA Research and Innovation Centre, S. Michele all’Adige, TN, Italy.} Corresponding author: cindyverdu@gmail.com

I

ntroduction

Cider quality is dependant on polyphenol content : they affect astringency, bitterness, color and aroma. Five main groups of phenolic compounds are present in the apple fruit: flavanols, hydroxycinnamic acids, dihydrochalcones, flavonols and anthocyanins. Their regulation by transcription factors is well known as well as their biosynthesis. Furthermore, the apple genome has been sequenced and annotated, which facilitate candidate gene identification.

Variability of phenolic compounds has been widely studied in apple germplasm. But until now, only two QTL studies have been performed, both on dessert apple progenies.

R

esults

o48 QTL identified at genome wide (GW) threshold on nine linkage groups (LG) of the integrated map forflavanols,flavonols,dihydrochalconesandhydroxycinnamic acids.

o11 main clusters located on six LG including QTL obtained at GW and LG threshold.

M

aterial and Methods

Florina Prima

X4972 X3189

X8402 Kermerrien X8443

X5210

Cider progeny: 285 trees x x x x P la n t m a te ri a l

> The aim of this work is to perform a QTL analysis and a candidate gene

research on the phenolic compounds present in fruit extracts and juices

prepared from a cider apple progeny.

F3’H HCT DFR Shikimate Phenylalanine Cinnamic acid p-coumaric acid 4-coumaroyl CoA (+ 3 Malonyl CoA) Naringenin chalcone Naringenin Dihydrokaempferol Caffeoyl CoA (+ 3 Malonyl CoA) Eriodictyol chalcone Eriodictyol Dihydroquercetin Leucocyanidin Phloretin Phloretin glycosides (phloridzine, phloretin xyloglucoside) Catechin Procyanidines PAL C4H Caffeoylquinic acid p-coumaroylquinic acid 4CL CHS CHI FHT CHS CHI FHT F3’H LAR ? T y ro s in e T A L 4-hydroxydihydrocinnamoyl CoA DH CHS D2’GT C3’H Caffeic acid HCT Flavanols Dihydrochalcones Hydroxycinnamic acids 4CL C3’H HQT o11 main clusters located on six LG including QTL obtained at GW and LG threshold.

oConfidence interval for clusters on LG 1, 3, 12, 15 and 17 significantly reduced with Meta-QTL analysis.

oSeveral enzymes and transcription factors implicated in the phenolic pathway identified by in silico candidate gene research.

Cider progeny: 285 trees

2008: 92 2009: 137 2009: 209 2010: 120 HPLC-UV 15 compounds + DPm of flavanols and procyanidins 2009 UHPLC-MS/MS 14 compounds 2010 UHPLC-UV 28 compounds S a m pl e pr e pa ra ti o n Q ua n ti fi ca ti o n 2008 2009 QTL Detection: MapQTL Meta-QTL analysis: MetaQTL Candidate genes identification: BLAST2GO LG17 LG17 HCT/ HQT HCT/ HQT

4 QTL for chlorogenic acid Fruit 08, 09 & Juice 09, 10 33 < r² < 43.6 4 QTL for chlorogenic acid Fruit 08, 09 & Juice 09, 10 33 < r² < 43.6 MYB bHLH WD40 MYB bHLH WD40 LG12 LG12 FLS FLS 8 QTL for flavanols Fruit 08, 09 & Juice 09, 10 3 < r² < 20 8 QTL for flavanols Fruit 08, 09 & Juice 09, 10 3 < r² < 20

8 QTL for flavanols Fruit 08, 09 & Juice 09, 10 3 < r² < 20 8 QTL for flavanols Fruit 08, 09 & Juice 09, 10 3 < r² < 20 LG1 LG1 F3’H F3’H 2 QTL for quercitrin Fruit 08 & Juice 10 28.2 < r² < 31.7 2 QTL for quercitrin Fruit 08 & Juice 10 28.2 < r² < 31.7

Cyanidin

Cyanidin glycosides (Ideain) Quercetin

Quercetin glycosides (avicularin, hyperin, isoquercitrin, quercitrin, reynoutrin, rutin)

Epicatechin FLS UFGT ANS UFGT ANR ? Anthocyanins Flavonols Kaempferol FLS F3’H

Figure. QTL meta-analysis for phenolic compounds quantified in fruit and juice prepared for two harvest years and candidate gene related to the biosynthethic pathway. Meta-QTLs are represented as full bars on the right side of the LG. Details on QTL included in meta-QTL analysis

are described close to the meta-QTL. Candidate genes found close to the meta-QTL are indicated in the arrow on the left side of the LG.

C

onclusion

oMany QTL obtained for phenolic compounds quantified in fruit extracts and apple juices prepared in two harvest years. Several clusters identified for four phenolic groups.

oThe meta-QTL analysis was a powerful tool to reduce confidence interval of these clusters.

oBLAST2GO software allowed a rapid analysis of putative gene functions present underneath QTL confidence interval.

Acknowledgment

This work was supported by a PhD grant funding from the SFR 149 QUASAV (Structure Fédérative de Recherche: Qualité et Santé du Végétal), Angers, France and the inter-regional (Bretagne-Pays de la Loire) project INNOVACIDRE. Participation to RGC6 was funded by a grant awarded by the “Académie d’Agriculture de France”.

LG3 LG3

DFR DFR

6 QTL for procyanidins Fruit 09 & Juice 09, 10 2.3 < r² < 20.6 6 QTL for procyanidins Fruit 09 & Juice 09, 10 2.3 < r² < 20.6 UFGT

UFGT

15 QTL for flavanols Fruit 08, 09 & Juice 09, 10 6.2 < r² < 33.3 15 QTL for flavanols Fruit 08, 09 & Juice 09, 10 6.2 < r² < 33.3

Sixth Rosaceous Genomics Conference 30th september-4th october 2012