75 Integrating Membrane Transport with Male Gametophyte ... - TAIR

223 Quantitative Trait Analysis of Arabidopsis thaliana Root Behavior on a Tilted Hard Agar
Surface
Laura Vaughn, Patrick Masson
University of Wisconsin - Madison
Arabidopsis thaliana roots grown on hard, tilted agar surfaces show characteristic behaviors. Two such behaviors are
root growth away from the vertical, known as skewing, and alternating tip growth from right to left resulting in a wavelike
pattern. These phenotypes are complex and vary somewhat between the roots of an individual Arabidopsis accession.
They also differ greatly when multiple accessions are compared. To discern genetic and environmental components of
these traits, quantitative trait loci mapping and analysis will be undertaken. The goal of the study is to elucidate some of
the genes contributing to the behaviors and their ecological and evolutionary significance.
224 Connecting Auxin Function & Sugar Metabolism: the FANTASTIC FOUR (FAF) Protein Family
in Arabidopsis thaliana Development
Vanessa Wahl, Luise Brand, Sarah Fehr, Markus Schmid
MPI for Developmental Biology
Based on expression profiling of flowering time mutants (1), we chose a previously uncharacterized, plant specific
gene family, now called FANTASTIC FOUR (FAF), with four members in Arabidopsis for further investigation.
Expression of the FAF genes is extensively regulated throughout development (2). RNA in situ analysis and reporter
lines demonstrate that all four FAF genes are strongly expressed in the vasculature, including the pro-vasculature, but
individual FAFs are present in distinct domains that overlap only partially. Constitutive expression of the FAF genes
resulted in phenotypic effects that appeared auxin related, including defects in the vasculature. Knock-down of the FAF
genes led to distortion of the vein formation in leaves, demonstrating that the FAF genes play a critical role in regulating
vascular development.
To gain insight into the function of the FAF gene family during Arabidopsis development we have carried out
microarray analysis on plants constitutively expressing individual FAF genes. All lines show a deregulation of auxin
regulated genes. In addition, expression of enzymes involved in sugar metabolism, especially trehalose synthesis, and
lignin as well as flavonoid biosynthesis were affected as well.
(1) Schmid et al., Development, 2003, 130, 6001.
(2) Schmid et al., Nature Genetics, 2005, 37, 501.