Plant Cell Reports

, Volume 30, Issue 8, pp 1485–1492

Expression patterns of several floral genes during flower initiation in the apical buds of apple (Malus × domestica Borkh.) revealed by in situ hybridization

Authors

  • Naozumi Mimida
    • Faculty of AgricultureIwate University
  • Ayano Ureshino
    • Apple Breeding and Physiology Research TeamApple Research Station, National Institute of Fruit Tree Science
  • Norimitsu Tanaka
    • Faculty of Agriculture and Life ScienceHirosaki University
  • Narumi Shigeta
    • Faculty of AgricultureIwate University
  • Noriko Sato
    • Faculty of AgricultureIwate University
  • Yuki Moriya-Tanaka
    • Apple Breeding and Physiology Research TeamApple Research Station, National Institute of Fruit Tree Science
  • Hiroshi Iwanami
    • Apple Breeding and Physiology Research TeamApple Research Station, National Institute of Fruit Tree Science
  • Chikako Honda
    • Apple Breeding and Physiology Research TeamApple Research Station, National Institute of Fruit Tree Science
  • Akira Suzuki
    • Faculty of AgricultureIwate University
  • Sadao Komori
    • Faculty of AgricultureIwate University
    • Apple Breeding and Physiology Research TeamApple Research Station, National Institute of Fruit Tree Science
Original Paper

DOI: 10.1007/s00299-011-1057-3

Cite this article as:
Mimida, N., Ureshino, A., Tanaka, N. et al. Plant Cell Rep (2011) 30: 1485. doi:10.1007/s00299-011-1057-3

Abstract

The apple (Malus × domestica Borkh.) is one of the commercially important fruit crops in the worldwide. The apple has a relatively long juvenile period (up to 4 years) and a long reproductive period between the flower initiation and the mature fruit (14–16 months), which prevent the fruit breeding. Therefore, the understanding of the flowering system is important to improve breeding efficiency in the apple. In this study, to examine the temporal and spatial expression patterns of the floral genes, MdTFL1, MdAP1 (MdMASD5), AFL2, and MdFT, we conducted in situ hybridization analysis in the apple shoot apex. In vegetative phase, MdTFL1 was expressed on the rib meristem zone. When vegetative meristem began converting into inflorescence meristem, the expression level of MdTFL1 was drastically decreased. At the early stage of inflorescence meristem, the expression levels of AFL2, MdFT, and MdAP1 were up-regulated in the leaf primordia and the upper region of cell layers on the shoot apex. In late stage, the expression levels of AFL2 and MdAP1 were up-regulated in the young floral primordia. At a more advanced stage, high expression of MdAP1 was observed in the inflorescence primordium through the inner layer of sepal primordia and the outer layer of receptacle primordia and floral axis. Our results suggest that AFL2, MdFT, and MdAP1 affect to convert from the vegetative meristem into the inflorescence meristem after the decline of MdTFL1 expression. After that, AFL2 and MdAP1 promote the formation of the floral primordia and floral organs.

Keywords

Apical meristem Apple Flowering gene Phase transition

Abbreviations

AP1

APETALA1

CEN

CENTRORADIALIS

FT

FLOWERING LOCUS T

LFY

LEAFY

Md

Malus × domestica

PEBP

Phosphatidylethanolamine binding protein

RT–PCR

Reverse transcription-polymerase chain reaction

SOC1

SUPRESSOR OF OVEREXPRESSION OF CONSTANS1

TFL1

TERMINAL FLOWER1

UTR

Untranslational region

Copyright information

© Springer-Verlag 2011