Skip to main content

Molecular analysis of auxin-specfic signal transduction in plant communication

Objective

The primary objective is to produce basic knowledge on the mechanisms by which a variety of signals control growth and cell differentiation. The secondary objective will be to develop tools at cellular and molecular levels to render morphogenetic events accessible to scientific analysis.
Several novel ERabp genes have been cloned from maize and Arabidopsis to allow structural and functional analysis of their role in auxin perception. Transgenic tobacco plants have been generated expressing these proteins and demonstrating increased auxin sensitivity and altered root growth characteristics. Analysis of their cellular expression and trafficking will present a major step forward to understanding their function. Anti-peptide antibodies with auxin agonist activity have been used to identify the auxin binding region of an auxin receptor. 2 monoclonal antibodies against the auxin receptor have been found to be excellent markers for endoplasmic reticulum (ER), especially in mammalian cells. An assay system for early auxin responses has been developed along with functional analysis of auxin agonist antibodies and a demonstration of increased auxin sensitivity in transgenic tobacco plants overexpressing an auxin binding protein. Mutant cdc2 genes have been found to influence cell division in plants and provide perspectives to alter development. The availability of 2 cdc2 genes and 5 cyclin genes now allows study of the influence of plant hormones, in particular auxins and cytokinins, on cell division. The cell specific expression pattern of an Arabidopsis gene encoding a small guanosine triphosphate (GTP) binding protein has been characterised and is a major step forward in understanding its cellular function. Peptides have been synthesized that correspond in sequence to a number of G protein sequnces, and antisera raised against these peptides have been characterized.
Auxins evoke a remarkable diversity of growth responses, including differentiation and morphogenesis, control of apical dominance and the stimulation of root growth. The advent of the powerful techniques for genetic engineering plant transformation and electrophysiological analysis offers a unique opportunity to experimentally investigate the molecular mechanisms of auxin action. Detailed knowledge in plant signal transduction, cell division and its hormonal control will be essential to finally control plant regeneration.

Research tasks:

to identify and characterize genes encoding putative receptors for the phytohormone auxin with a view to understanding at the molecular level the primary physiological and morphogenic consequences of auxin action;
to investigate properties of intracellular signalling chains including genes encoding GTP-binding proteins or genes controlling plant cell division;
to use transgenic plants to assign functions to these genes and determine directly their influence on plant growth control and morphogenesis.

Coordinator

MAX-PLANCK-GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN E.V.
Address
Carl-von-linné-weg 10
50829 Koeln
Germany

Participants (5)

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
France
Address
Avenue De La Terrasse 1Bètiment 23
91190 Gif Sur Yvette
DANISCO A/S
Denmark
Address
1,Langebrogade 1
1001 Koebenhavn K/copenhaegen
GENT UNIVERSITY
Belgium
Address
Sint Pietersnieuwstraat 25
9000 Gent
Horticulture Research International
United Kingdom
Address
East Malling
ME19 6BJ West Malling
UNIVERSITY OF LEEDS
United Kingdom
Address
Woodhouse Lane
LS2 9JT Leeds