Planta

, 234:737

Expression, subcellular localization, and cis-regulatory structure of duplicated phytoene synthase genes in melon (Cucumis melo L.)

  • Xiaoqiong Qin
  • Ardian Coku
  • Kentaro Inoue
  • Li Tian
Original Article

DOI: 10.1007/s00425-011-1442-8

Cite this article as:
Qin, X., Coku, A., Inoue, K. et al. Planta (2011) 234: 737. doi:10.1007/s00425-011-1442-8

Abstract

Carotenoids perform many critical functions in plants, animals, and humans. It is therefore important to understand carotenoid biosynthesis and its regulation in plants. Phytoene synthase (PSY) catalyzes the first committed and rate-limiting step in carotenoid biosynthesis. While PSY is present as a single copy gene in Arabidopsis, duplicated PSY genes have been identified in many economically important monocot and dicot crops. CmPSY1 was previously identified from melon (Cucumis melo L.), but was not functionally characterized. We isolated a second PSY gene, CmPSY2, from melon in this work. CmPSY2 possesses a unique intron/exon structure that has not been observed in other plant PSYs. Both CmPSY1 and CmPSY2 are functional in vitro, but exhibit distinct expression patterns in different melon tissues and during fruit development, suggesting differential regulation of the duplicated melon PSY genes. In vitro chloroplast import assays verified the plastidic localization of CmPSY1 and CmPSY2 despite the lack of an obvious plastid target peptide in CmPSY2. Promoter motif analysis of the duplicated melon and tomato PSY genes and the Arabidopsis PSY revealed distinctive cis-regulatory structures of melon PSYs and identified gibberellin-responsive motifs in all PSYs except for SlPSY1, which has not been reported previously. Overall, these data provide new insights into the evolutionary history of plant PSY genes and the regulation of PSY expression by developmental and environmental signals that may involve different regulatory networks.

Keywords

CarotenoidGene duplicationMelonPhytoene synthasePlastidGene regulation

Abbreviations

ABA

Abscisic acid

ABRE-CE

ABA-response element–coupling element

CTAB

Cetyltrimethyl ammonium bromide

DAP

Days after pollination

EST

Expressed sequence tag

FPP

Farnesyl pyrophosphate

GGPP

Geranylgeranyl pyrophosphate

GST

Glutathione-S-transferase

HSE

High temperature responsive element

IPTG

Isopropyl-β-d-thiogalactoside

LTR

Low temperature responsiveness element

LB

Luria Broth

NJ

Neighbor-joining

PIF

Phytochrome interacting factor

PSY

Phytoene synthase

RACE

Rapid amplification of cDNA ends

SDS-PAGE

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis

SNP

Single nucleotide polymorphism

TCA

Trichloroacetic acid

TILLING

Targeting induced local lesions IN genomes

Supplementary material

425_2011_1442_MOESM1_ESM.pdf (41 kb)
Supplementary material 1 (PDF 41 kb)
425_2011_1442_MOESM2_ESM.pdf (12 kb)
Supplementary material 2 (PDF 12 kb)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Xiaoqiong Qin
    • 1
  • Ardian Coku
    • 1
  • Kentaro Inoue
    • 1
  • Li Tian
    • 1
  1. 1.Department of Plant Sciences, Mail Stop 3University of California, DavisDavisUSA