Canopy shade causes a rapid and transient arrest in leaf development through auxin-induced cytokinin oxidase activity.
A plant grown under canopies perceives the reduction in the ratio of red (R) to far-red (FR) light as a warning of competition, and enhances elongation growth in an attempt to overgrow its neighbors. Here, we report that the same low R/FR signal that induces hypocotyl elongation also triggers a rapid arrest of leaf primordium growth, ensuring that plant resources are redirected into extension growth. The growth arrest induced by low R/FR depends on auxin-induced cytokinin breakdown in incipient vein cells of developing primordia, thus demonstrating the existence of a previously unrecognized regulatory circuit underlying plant response to canopy shade.
Institute of Molecular Biology and Pathology, National Research Council, 00185 Rome, Italy.
Monica
M
Carabelli
Marco
M
Possenti
Giovanna
G
Sessa
Andrea
A
Ciolfi
Massimiliano
M
Sassi
Giorgio
G
Morelli
Ida
I
Ruberti
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism* / Q000528:radiation effects; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D005966:Glucuronidase / Q000235:genetics; D007210:Indoleacetic Acids / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D018462:Photobiology; D018515:Plant Leaves / Q000254:growth & development* / Q000378:metabolism* / Q000528:radiation effects; D030821:Plants, Genetically Modified; D015398:Signal Transduction
D007210:Indoleacetic Acids; D010088:Oxidoreductases; C019984:cytokinin oxidase; D005966:Glucuronidase