An endogenous carbon-sensing pathway triggers increased auxin flux and hypocotyl elongation.
The local environment has a substantial impact on early seedling development. Applying excess carbon in the form of sucrose is known to alter both the timing and duration of seedling growth. Here, we show that sucrose changes growth patterns by increasing auxin levels and rootward auxin transport in Arabidopsis (Arabidopsis thaliana). Sucrose likely interacts with an endogenous carbon-sensing pathway via the PHYTOCHROME-INTERACTING FACTOR (PIF) family of transcription factors, as plants grown in elevated carbon dioxide showed the same PIF-dependent growth promotion. Overexpression of PIF5 was sufficient to suppress photosynthetic rate, enhance response to elevated carbon dioxide, and prolong seedling survival in nitrogen-limiting conditions. Thus, PIF transcription factors integrate growth with metabolic demands and thereby facilitate functional equilibrium during photomorphogenesis.
Department of Biology, University of Washington, Seattle, Washington 98195, USA.
Jodi L Stewart
JL
Lilley
Christopher W
CW
Gee
Ilkka
I
Sairanen
Karin
K
Ljung
Jennifer L
JL
Nemhauser
D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D002244:Carbon / Q000378:metabolism*; D017343:Genes, Plant / Q000235:genetics; D018546:Hypocotyl / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D008954:Models, Biological; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013395:Sucrose / Q000494:pharmacology
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D013395:Sucrose; D002244:Carbon