Arabidopsis cryptochrome 1 functions in nitrogen regulation of flowering.
The phenomenon of delayed flowering after the application of nitrogen (N) fertilizer has long been known in agriculture, but the detailed molecular basis for this phenomenon is largely unclear. Here we used a modified method of suppression-subtractive hybridization to identify two key factors involved in N-regulated flowering time control in Arabidopsis thaliana, namely ferredoxin-NADP(+)-oxidoreductase and the blue-light receptor cryptochrome 1 (CRY1). The expression of both genes is induced by low N levels, and their loss-of-function mutants are insensitive to altered N concentration. Low-N conditions increase both NADPH/NADP(+) and ATP/AMP ratios, which in turn affect adenosine monophosphate-activated protein kinase (AMPK) activity. Moreover, our results show that the AMPK activity and nuclear localization are rhythmic and inversely correlated with nuclear CRY1 protein abundance. Low-N conditions increase but high-N conditions decrease the expression of several key components of the central oscillator (e.g., CCA1, LHY, and TOC1) and the flowering output genes (e.g., GI and CO). Taken together, our results suggest that N signaling functions as a modulator of nuclear CRY1 protein abundance, as well as the input signal for the central circadian clock to interfere with the normal flowering process.
College of Life Science, Capital Normal University, Beijing 100048, China; College of Resources Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; roundtree318@hotmail.com yhe@cnu.edu.cn.
Shu
S
Yuan
College of Resources Science and Technology, Sichuan Agricultural University, Chengdu 611130, China;
Zhong-Wei
ZW
Zhang
College of Life Science, Capital Normal University, Beijing 100048, China;
Chong
C
Zheng
College of Life Science, Capital Normal University, Beijing 100048, China; Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, Chengdu 610064, China;
Zhong-Yi
ZY
Zhao
College of Life Science, Capital Normal University, Beijing 100048, China;
Yu
Y
Wang
College of Resources Science and Technology, Sichuan Agricultural University, Chengdu 611130, China;
Ling-Yang
LY
Feng
College of Life Science, Capital Normal University, Beijing 100048, China;
Guoqi
G
Niu
College of Resources Science and Technology, Sichuan Agricultural University, Chengdu 611130, China;
Chang-Quan
CQ
Wang
Horticulture Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China;
Jian-Hui
JH
Wang
School of Life Sciences, Chengdu Normal College, Chengdu 611130, China;
Hong
H
Feng
Center of Applied Biotechnology, Wuhan Institute of Bioengineering, Wuhan 430415, China;
Fei
F
Xu
College of Life Science, Capital Normal University, Beijing 100048, China;
Fang
F
Bao
College of Life Science, Capital Normal University, Beijing 100048, China;
Yong
Y
Hu
College of Life Science, Capital Normal University, Beijing 100048, China;
Ying
Y
Cao
College of Life Science, Capital Normal University, Beijing 100048, China;
Ligeng
L
Ma
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
Haiyang
H
Wang
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Dong-Dong
DD
Kong
College of Life Science, Capital Normal University, Beijing 100048, China;
Wei
W
Xiao
Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, Chengdu 610064, China;
Hong-Hui
HH
Lin
College of Life Science, Capital Normal University, Beijing 100048, China; roundtree318@hotmail.com yhe@cnu.edu.cn.
Yikun
Y
He
D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000502:physiology*; D057906:Circadian Clocks; D056931:Cryptochromes / Q000502:physiology*; D005287:Ferredoxin-NADP Reductase / Q000378:metabolism*; D035264:Flowers / Q000502:physiology*; D009154:Mutation; D009249:NADP / Q000378:metabolism; D009584:Nitrogen / Q000502:physiology*; D066251:Subtractive Hybridization Techniques
D029681:Arabidopsis Proteins; C538962:CRY1 protein, Arabidopsis; D056931:Cryptochromes; D009249:NADP; D000255:Adenosine Triphosphate; D005287:Ferredoxin-NADP Reductase; D055372:AMP-Activated Protein Kinases; D009584:Nitrogen
adenosine monophosphate-activated protein kinase; circadian clock; cryptochrome 1; ferredoxin-NADP+-oxidoreductase 1; nitrogen-regulated flowering