Edinburgh, Scotland, United Kingdom - TAIR

Auxin transport – connecting cell polarity and
patterning
Auxin is a prominent intercellular signal in plants and acts as a versatile trigger
of developmental change. Directional, active, cell-to-cell transport over short
distances mediates differential auxin distributions within tissues (auxin gradients)
that are required for various patterning processes, including apical-basal axis
formation, organogenesis and tropisms. Various environmental and endogenous
signals can be integrated into changes in auxin distribution through their effects
on intercellular auxin transport. Differentially expressed auxin transporters of the
PIN family, each with specific polar, subcellular localization form a network for
directional auxin distribution and formation of these local gradients. The activity
of PIN proteins can be regulated at the single cell level by changes in their
vesicle trafficking-dependent polar targeting. PIN proteins undergo cycles of a
clathrin-dependent endocytosis and ARF GEF-dependent recycling that serves
to feed-back regulate throughput and directionality of intercellular auxin flow.
Thus, the PIN-dependent auxin transport network, whose directional throughput
is modulated by both endogenous and exogenous signals, provides one of the
mechanisms underlying the plasticity and adaptability of plant development.
43
L18
Friday 12:00 - 12:30
Cell Biology
Jiri Friml
Department of Plant
Systems Biology
VIB
and Department of Plant
Biotechnology and Genetics
Ghent University
9052 Gent
Belgium