Auxin-induced inhibition of lateral root initiation contributes to root system shaping in Arabidopsis thaliana
Por:
Ivanchenko M.G., Napsucialy-Mendivil S., Dubrovsky J.G.
Publicada:
1 dic 2010
Resumen:
P>The hormone auxin is known to inhibit root elongation and to promote initiation of lateral roots. Here we report complex effects of auxin on lateral root initiation in roots showing reduced cell elongation after auxin treatment. In Arabidopsis thaliana, the promotion of lateral root initiation by indole-3-acetic acid (IAA) was reduced as the IAA concentration was increased in the nanomolar range, and IAA became inhibitory at 25 nm. Detection of this unexpected inhibitory effect required evaluation of root portions that had newly formed during treatment, separately from root portions that existed prior to treatment. Lateral root initiation was also reduced in the iaaM-OX Arabidopsis line, which has an endogenously increased IAA level. The ethylene signaling mutants ein2-5 and etr1-3, the auxin transport mutants aux1-7 and eir1/pin2, and the auxin perception/response mutant tir1-1 were resistant to the inhibitory effect of IAA on lateral root initiation, consistent with a requirement f
Filiaciones:
Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Biol Mol Plantas, Cuernavaca 62250, Morelos, Mexico
Department of Botany and Plant Pathology, 2082 Cordley Hall, Oregon State University, Corvallis, OR 97331, United States
All Open Access; Bronze
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