Abstract
Phototropins (phot1 and phot2) are plant-specific blue light receptors for phototropism, chloroplast movement, leaf expansion, and stomatal opening. All these responses are thought to optimize photosynthesis by helping to capture light energy efficiently, reduce photodamage, and acquire CO2. However, experimental evidence for the promotion of plant growth through phototropins is lacking. Here, we report dramatic phototropin-dependent effects on plant growth. When plants of Arabidopsis thaliana wild type, the phot1 and phot2 mutants, and the phot1 phot2 double mutant were grown under red light, no significant growth differences were observed. However, if a very low intensity of blue light (0.1 μmol m-2 s-1) was superimposed on red light, large increases in fresh weight up to threefold were found in those plants that carried functional PHOT1 genes. When the intensity of blue light was increased to 1 μmol m-2 s-1, the growth enhancement was also found in the phot1 single mutant, but not in the double mutant, indicating that phot2 mediated similar responses as phot1 with a lower sensitivity. The effects occurred under low photosynthetically active radiation in particular. The well-known physiological phototropin-mediated responses, including chloroplast movement, stomatal opening, and leaf expansion, in the different lines tested indicated an involvement of these responses in the blue light-induced growth enhancement. We conclude that phototropins promote plant growth by controlling and integrating a variety of responses that optimize photosynthetic performance under low photosynthetically active radiation in the natural environment.
| Original language | English |
|---|---|
| Pages (from-to) | 1120-1127 |
| Number of pages | 8 |
| Journal | Plant Cell |
| Volume | 17 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Dec 1 2005 |
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All Science Journal Classification (ASJC) codes
- Plant Science
- Cell Biology
Cite this
Phototropins promote plant growth in response to blue light in low light environments. / Takemiya, Atsushi; Inoue, Shin Ichiro; Doi, Michio; Kinoshita, Toshinori; Shimazaki, Ken Ichiro.
In: Plant Cell, Vol. 17, No. 4, 01.12.2005, p. 1120-1127.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Phototropins promote plant growth in response to blue light in low light environments
AU - Takemiya, Atsushi
AU - Inoue, Shin Ichiro
AU - Doi, Michio
AU - Kinoshita, Toshinori
AU - Shimazaki, Ken Ichiro
PY - 2005/12/1
Y1 - 2005/12/1
N2 - Phototropins (phot1 and phot2) are plant-specific blue light receptors for phototropism, chloroplast movement, leaf expansion, and stomatal opening. All these responses are thought to optimize photosynthesis by helping to capture light energy efficiently, reduce photodamage, and acquire CO2. However, experimental evidence for the promotion of plant growth through phototropins is lacking. Here, we report dramatic phototropin-dependent effects on plant growth. When plants of Arabidopsis thaliana wild type, the phot1 and phot2 mutants, and the phot1 phot2 double mutant were grown under red light, no significant growth differences were observed. However, if a very low intensity of blue light (0.1 μmol m-2 s-1) was superimposed on red light, large increases in fresh weight up to threefold were found in those plants that carried functional PHOT1 genes. When the intensity of blue light was increased to 1 μmol m-2 s-1, the growth enhancement was also found in the phot1 single mutant, but not in the double mutant, indicating that phot2 mediated similar responses as phot1 with a lower sensitivity. The effects occurred under low photosynthetically active radiation in particular. The well-known physiological phototropin-mediated responses, including chloroplast movement, stomatal opening, and leaf expansion, in the different lines tested indicated an involvement of these responses in the blue light-induced growth enhancement. We conclude that phototropins promote plant growth by controlling and integrating a variety of responses that optimize photosynthetic performance under low photosynthetically active radiation in the natural environment.
AB - Phototropins (phot1 and phot2) are plant-specific blue light receptors for phototropism, chloroplast movement, leaf expansion, and stomatal opening. All these responses are thought to optimize photosynthesis by helping to capture light energy efficiently, reduce photodamage, and acquire CO2. However, experimental evidence for the promotion of plant growth through phototropins is lacking. Here, we report dramatic phototropin-dependent effects on plant growth. When plants of Arabidopsis thaliana wild type, the phot1 and phot2 mutants, and the phot1 phot2 double mutant were grown under red light, no significant growth differences were observed. However, if a very low intensity of blue light (0.1 μmol m-2 s-1) was superimposed on red light, large increases in fresh weight up to threefold were found in those plants that carried functional PHOT1 genes. When the intensity of blue light was increased to 1 μmol m-2 s-1, the growth enhancement was also found in the phot1 single mutant, but not in the double mutant, indicating that phot2 mediated similar responses as phot1 with a lower sensitivity. The effects occurred under low photosynthetically active radiation in particular. The well-known physiological phototropin-mediated responses, including chloroplast movement, stomatal opening, and leaf expansion, in the different lines tested indicated an involvement of these responses in the blue light-induced growth enhancement. We conclude that phototropins promote plant growth by controlling and integrating a variety of responses that optimize photosynthetic performance under low photosynthetically active radiation in the natural environment.
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UR - http://www.scopus.com/inward/citedby.url?scp=23944471774&partnerID=8YFLogxK
U2 - 10.1105/tpc.104.030049
DO - 10.1105/tpc.104.030049
M3 - Article
C2 - 15749755
AN - SCOPUS:23944471774
VL - 17
SP - 1120
EP - 1127
JO - Plant Cell
JF - Plant Cell
SN - 1040-4651
IS - 4
ER -