Planta

, Volume 233, Issue 5, pp 883–894

Effects of seasonal temperature changes on DkMyb4 expression involved in proanthocyanidin regulation in two genotypes of persimmon (Diospyros kaki Thunb.) fruit

  • Takashi Akagi
  • Tomoyuki Tsujimoto
  • Ayako Ikegami
  • Keizo Yonemori
Original Article

Abstract

Persimmon fruits accumulate a large amount of proanthocyanidin (PA). Fruits of the mutant non-astringent (NA) type lose their ability to accumulate PA at an early stage of fruit development, whereas fruits of the normal astringent (A) type sustain PA accumulation until ripening. This allelotype is determined by the genotype of a single ASTRINGENCY (AST) locus. It is possible that the reduction in PA accumulation in NA-type fruits is due to phenological down-regulation of DkMyb4 (a PA regulator) and the resultant down-regulation of structural genes in the PA pathway. In this study, attempts were made to identify the regulatory mechanisms of phenological PA accumulation in A- and NA-type fruits, focusing particularly on the effects of ambient temperature. Continuous cool temperature conditions caused sustained expression of DkMyb4 in NA-type fruits, as well as in A-type fruits, resulting in increased expression of PA pathway genes and PA accumulation. However, the expression of some A/NA phenotypic marker genes was not significantly affected by the cool temperature conditions. In addition, PA composition in NA-type fruits exposed to cool temperatures differed from that in A-type fruits. These results indicate that a cool ambient temperature may have induced DkMyb4 expression and resultant PA accumulation, but did not directly affect the expression of the AST gene.

Keywords

Astringency Myb Persimmon Proanthocyanidin Temperature 

Abbreviations

ANR

Anthocyanidin reductase

A-type

Astringent type

CA

Catechin

CHS

Chalcone synthase

EC

Epicatechin

EC-G

Epicatechin-gallate

EGC

Epigallocatechin

EGC-G

Epigallocatechin-gallate

F3′H

Flavonoid 3′-hydroxylase

F3′5′H

Flavonoid 3′5′-hydroxylase

GC

Gallocatechin

LAR

Leucoanthocyanidin reductase

NA-type

Non-astringent type

PA

Proanthocyanidin

TF

Transcription factor

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Takashi Akagi
    • 1
  • Tomoyuki Tsujimoto
    • 1
  • Ayako Ikegami
    • 2
  • Keizo Yonemori
    • 1
  1. 1.Laboratory of Pomology, Graduate School of AgricultureKyoto UniversityKyotoJapan
  2. 2.Laboratory of Pomology, Department of Bioproduction SciencesIshikawa Prefectural UniversityNonoichiJapan

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