Root growth in Arabidopsis requires gibberellin/DELLA signalling in the endodermis.
Gibberellins (GAs) are key regulators of plant growth and development. They promote growth by targeting the degradation of DELLA repressor proteins; however, their site of action at the cellular, tissue or organ levels remains unknown. To map the site of GA action in regulating root growth, we expressed gai, a non-degradable, mutant DELLA protein, in selected root tissues. Root growth was retarded specifically when gai was expressed in endodermal cells. Our results demonstrate that the endodermis represents the primary GA-responsive tissue regulating organ growth and that endodermal cell expansion is rate-limiting for elongation of other tissues and therefore of the root as a whole.
Ubeda-Tomás
Susana
S
Centre for Plant Integrative Biology, University of Nottingham, Loughborough, LE12 5RD, UK.
Swarup
Ranjan
R
Coates
Juliet
J
Swarup
Kamal
K
Laplaze
Laurent
L
Beemster
Gerrit T S
GT
Hedden
Peter
P
Bhalerao
Rishikesh
R
Bennett
Malcolm J
MJ
D017360:Arabidopsis / Q000033:anatomy & histology / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D005875:Gibberellins / Q000378:metabolism*; D018517:Plant Roots / Q000033:anatomy & histology / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D019076:Transgenes
D029681:Arabidopsis Proteins; C109555:GAI protein, Arabidopsis; D005875:Gibberellins; C508468:RGA protein, Arabidopsis; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins