Stem-piped light activates phytochrome B to trigger light responses in Arabidopsis thaliana roots.
The roles of photoreceptors and their associated signaling mechanisms have been extensively studied in plant photomorphogenesis with a major focus on the photoresponses of the shoot system. Accumulating evidence indicates that light also influences root growth and development through the light-induced release of signaling molecules that travel from the shoot to the root. We explored whether aboveground light directly influences the root system of Arabidopsis thaliana Light was efficiently conducted through the stems to the roots, where photoactivated phytochrome B (phyB) triggered expression of ELONGATED HYPOCOTYL 5 (HY5) and accumulation of HY5 protein, a transcription factor that promotes root growth in response to light. Stimulation of HY5 in response to illumination of only the shoot was reduced when root tissues carried a loss-of-function mutation in PHYB, and HY5 mutant roots exhibited alterations in root growth and gravitropism in response to shoot illumination. These findings demonstrate that the underground roots directly sense stem-piped light to monitor the aboveground light environment during plant environmental adaptation.
Department of Chemistry, Seoul National University, Seoul 08826, Korea.
Hyo-Jun
HJ
Lee
Department of Chemistry, Seoul National University, Seoul 08826, Korea.
Jun-Ho
JH
Ha
Center for Genome Engineering, Institute for Basic Science, Daejeon 34047, Korea.|Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany.
Sang-Gyu
SG
Kim
Department of Chemistry, Seoul National University, Seoul 08826, Korea.
Han-Kyu
HK
Choi
Department of Chemistry, Seoul National University, Seoul 08826, Korea.
Zee Hwan
ZH
Kim
Department of Biotechnology and Kumho Life Science Laboratory, Chonnam National University, Gwangju 61186, Korea.
Yun-Jeong
YJ
Han
Department of Biotechnology and Kumho Life Science Laboratory, Chonnam National University, Gwangju 61186, Korea.
Jeong-Il
JI
Kim
Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany.
Youngjoo
Y
Oh
Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany.
Variluska
V
Fragoso
Center for Nanoparticle Research, Institute for Basic Science, Seoul 08826, Korea.|School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Korea.
Kwangsoo
K
Shin
Center for Nanoparticle Research, Institute for Basic Science, Seoul 08826, Korea.|School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Korea.
Taeghwan
T
Hyeon
Department of Physics, Yonsei University, Seoul 03722, Korea.
Hong-Gu
HG
Choi
Department of Physics, Yonsei University, Seoul 03722, Korea.
Kyung-Hwan
KH
Oh
Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany. cmpark@snu.ac.kr baldwin@ice.mpg.de.
Ian T
IT
Baldwin
Department of Chemistry, Seoul National University, Seoul 08826, Korea. cmpark@snu.ac.kr baldwin@ice.mpg.de.|Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea.
Chung-Mo
CM
Park
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018522:Gravitropism / Q000502:physiology; D008027:Light; D051939:Phytochrome B / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
D029681:Arabidopsis Proteins; C497952:PHYB protein, Arabidopsis; D051939:Phytochrome B