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Overexpression of rice phytochrome A
in Arabidopsis: diverse role in multiple physiological
responses
CHUNFENG CHEN1, 2, YOU CHEN1,
QING ZHANG1, BENWEN CHEN3, CHENGWEI yANG1 AND yA QIN
WANG1,*
Abstract:
Phytochrome A
predominantly mediates responses to prolonged far-red light such as
the inhibition of hypocotyl elongation. It also acts in controlling
responses to FR light pulses. To investigate to what extent rice
phytochrome A complements the function of Arabidopsis
phytochrome A, we examined hypocotyl elongation
growth, seed germination, and greening in etiolated seedlings of
phyA-211 mutant plants, WT and two kinds of transgenic plants in
which WT and phyA-211 mutants overexpressed rice PHYA
cDNA. We found that ectopic expression of rice phytochrome A could
partially rescue the sensitivity of phyA-211 mutant hypocotyls
to prolonged far-red light and replace Arabidopsis phytochrome
A in the promotion of seed germination and recovery of the ability to
de-etiolate. Moreover, under end-of-day far-red light (EOD-FR), the
exogenous rice phytochrome A was found to restore some aspects of
growth in phyA-211 mutants, such as hypocotyl elongation,
petiole elongation and flowering time. The diverse role of rice
phytochrome A in the physiological responses of
Arabidopsis implies the substitution of phytochrome
signaling between monocots and dicots.
Abbreviations:
CAB, chlorophyll a/b binding protein; D, dark; EOD-FR, end-of-day far-red
light; FR, far-red; HIR, high-irradiance response; LFR, low-fluence
response; OsPHYA, rice phytochrome A; Pfr, far-red light-absorbing form
of phytochrome; Pr, red light-absorbing form of phytochrome; R, red;
R/FR, quantum ratio of red and far-red light; VLFR, very-low-fluence
response; W, white; WT, wild type.
1Guangdong Key Lab of Biotechnology for Plant Development, College of
Life Science, South China Normal University, Guangzhou 510631, PR
China
2
School of Bioscience
and Bioengineering, South China University of Technology, Guangzhou
510006, PR China
3
Chongqing Management
Center for Conversion of Farmland back to Forests, Chongqing 401121,
PR China
*Corresponding author E-mail:
yqwang@scut.edu.cn;
Tel: + 86 20 85210855; Fax: + 86 20 85215535
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