How does auxin enhance cell elongation? Roles of auxin-binding proteins and potassium channels in growth control.
Elongation growth and a several other phenomena in plant development are controlled by the plant hormone auxin. A number of recent discoveries shed light on one of the classical problems of plant physiology: the perception of the auxin signal. Two types of auxin receptors are currently known: the AFB/TIR family of F box proteins and ABP1. ABP1 appears to control membrane transport processes (H+ secretion, osmotic adjustment) while the TIR/AFBs have a role in auxin-induced gene expression. Models are proposed to explain how membrane transport (e.g., K+ and H+ fluxes) can act as a cross-linker for the control of more complex auxin responses such as the classical stimulation of cell elongation.
Christian
M
M
Biozentrum Klein Flottbek, Physiologie, Universität Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany.
Steffens
B
B
Schenck
D
D
Burmester
S
S
Böttger
M
M
Lüthen
H
H
D029681:Arabidopsis Proteins / Q000502:physiology; D049108:Cell Enlargement; D044783:F-Box Proteins / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids; D063245:Plant Development; D010937:Plant Growth Regulators / Q000502:physiology*; D010940:Plant Proteins / Q000502:physiology; D010944:Plants / Q000378:metabolism; D015221:Potassium Channels / Q000502:physiology*; D006180:Proton-Translocating ATPases / Q000502:physiology; D011523:Protoplasts / Q000502:physiology; D011956:Receptors, Cell Surface / Q000502:physiology
D029681:Arabidopsis Proteins; D044783:F-Box Proteins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; D015221:Potassium Channels; D011956:Receptors, Cell Surface; C501405:TIR1 protein, Arabidopsis; C046131:auxin receptor, plant; C083846:auxin-binding protein 1; D006180:Proton-Translocating ATPases