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Plant Mol Biol (2015) 87:633–643
DOI 10.1007/s11103-015-0302-5
Ectopic expression of a phytochrome B gene from Chinese
cabbage (Brassica rapa L. ssp. pekinensis) in Arabidopsis thaliana
promotes seedling de‑etiolation, dwarfing in mature plants,
and delayed flowering
Mei‑Fang Song · Shu Zhang · Pei Hou · Hong‑Zhong Shang · Hai‑Ke Gu ·
Jing‑Juan Li · Yang Xiao · Lin Guo · Liang Su · Jian‑Wei Gao · Jian‑Ping Yang
Received: 3 December 2013 / Accepted: 18 February 2015 / Published online: 28 February 2015
© Springer Science+Business Media Dordrecht 2015
of the BrPHYB gene in A. thaliana significantly enhances
seedling de-etiolation under red- and white-light condi-
tions, and causes dwarf stature in mature plants. Unexpect-
edly, overexpression of BrPHYB in transgenic A. thaliana
resulted in reduced expression of gibberellins biosynthesis
genes and delayed flowering under short-day conditions,
whereas AtPHYB overexpression caused enhanced expres-
sion of FLOWERING LOCUS T and earlier flowering. Our
results suggest that BrphyB might play an important role
in regulating the development of Chinese cabbage. BrphyB
and AtphyB have conserved functions during de-etiolation
and vegetative plant growth and divergent functions in the
regulation of flowering time.
Keywords Arabidopsis thaliana · Chinese cabbage ·
Ectopic expression · De-etiolation · Flowering time ·
Phytochrome B
Introduction
Light is a major environmental signal that affects multiple
plant developmental processes, including seed germina-
tion, photomorphogenesis, leaf expansion, stem elongation,
phototropism, stomata and chloroplast movement, shade
avoidance, circadian rhythms, and flowering time (Deng
and Quail 1999; Wang and Deng 2003; Jiao et al. 2007; Li
et al. 2011). Plants have evolved a variety of photorecep-
tors to monitor light changes in their environments (Wang
2005; Mathews 2005, 2006; Mathews and McBreen 2008).
In Arabidopsis thaliana, five distinct phytochromes, des-
ignated phytochrome A (phyA) to phyE, have been char-
acterized as red (R)/far-red (FR) reversible photoreceptors
(Sharrock and Quail 1989; Clack et al. 1994). PhyA is the
only light labile or type I phytochrome in A. thaliana, and
Abstract Phytochrome B (phyB) is an essential red light
receptor that predominantly mediates seedling de-etio-
lation, shade-avoidance response, and flowering time. In
this study, we isolate a full-length cDNA of PHYB, desig-
nated BrPHYB, from Chinese cabbage (Brassica rapa L.
ssp. pekinensis), and we find that BrphyB protein has high
amino acid sequence similarity and the closest evolutionary
relationship to Arabidopsis thaliana phyB (i.e., AtphyB).
Quantitative reverse transcription (RT)-PCR results indicate
that the BrPHYB gene is ubiquitously expressed in different
tissues under all light conditions. Constitutive expression
Mei-Fang Song, Shu Zhang and Pei Hou have contributed equally
to this work.
Electronic supplementary material The online version of this
article (doi:10.1007/s11103-015-0302-5) contains supplementary
material, which is available to authorized users.
M.-F. Song · H.-Z. Shang · H.-K. Gu
Beijing Radiation Center, Beijing 100875,
People’s Republic of China
M.-F. Song · S. Zhang · J.-J. Li · J.-W. Gao (*)
Institute of Vegetables and Flowers, Shandong Academy
of Agricultural Sciences/Shandong Key Laboratory
of Greenhouse Vegetable Biology, Jinan 250100,
People’s Republic of China
e-mail: jianweigao3@yahoo.com
M.-F. Song · P. Hou · L. Guo · L. Su · J.-P. Yang (*)
Institute of Crop Sciences, Chinese Academy of Agricultural
Sciences, 12 Zhongguancun South Street, Haidian District,
Beijing 100081, People’s Republic of China
e-mail: yangjianping02@caas.cn
Y. Xiao
Graduate School, Chinese Academy of Agricultural Sciences,
Beijing 100081, People’s Republic of China
@Phil_Robichaud
@deepthiw
@JoseServera