Currently
the Gilroy Lab has numerous research areas:
Signaling
during the graviresponse of roots.
We primarily use Araibidopsis for gravitropism
experiments because of the interesting mutants available and because
it is amenable to transformation, however some of our studies use
corn, Limnobium, and other plant species. We are interested in not
only how the gravity signal is transduced in the individual cells
of the cap that perceive gravity but also how that signal is translocated
to the responding cells in the elongation zone. In addition, we are
investigating how roots respond when they grow down into a barrier.
For these and the gravitropism studies we use time-lapse video, GFP
fluorescence microscopy, imaging of ion concentrations, laser ablation,
laser tweezers, microinjection, and digital image analysis. More...
Barley
aleurone cell signal transduction in response to plant hormones.
The cereal aleurone cell is well established as a model system for
studying hormonal regulation of plant cells. The aleurone of the barley
grain is a digestive tissue that secretes hydrolases that mobilize
endosperm reserves during germination. The synthesis and secretion
of these hydrolases (principally alpha-amylases) is under hormonal
regulation. Gibberellin (GA) stimulates alpha-amylase synthesis and
secretion, whereas abscisic acid (ABA) reverses this effect. The site
of perception of these hormones in the aleurone cell is now tentatively
assigned to the plasma membrane. However, the signal transduction
events leading from the receptor to the coordination of the complex
events that make up and regulate the secretory activity of these cells
are still poorly understood. It is these events that we are interested
in studying. More...
Signaling
in Chara rhizoids while they respond to gravity.
Rhizoids are thread-like structures that grow out of the nodes of
the alga Chara. They anchor the alga and facilitate nutrient uptake,
thus functioning similar to the roots of plants. However, unlike the
multicelluar root, Chara rhizoids are single cells that both sense
and respond to gravity. We are curious to unravel the signal transduction
that occurs in a rhizoid when it is gravistimulated. Rhizoids are
amenable to many of the microscopy techniques that we implement to
study root gravitropism. More...
Control
of tip growth in root hairs.
Root hairs are initiated in certain epidermal cells (trichoblasts)
in the maturation zone of the root and then extend away from the root
surface by tip growth. These projections increase the surface area
of the root for enhanced nutrient and water absorbtion. How the trichoblast
initiates the bulge of a new root hair and how directional tip growth
is maintained at the cellular level is a focus of Gilroy lab research.
More...
Introduction
to root gravitropism. Why do roots grow
down? If this is something you haven't thought much about, then you
should look here for a good introduction. Many topics are covered
here, from the structure of gravisensing cells to the involvement
of hormones in root curviture. These pages also contain outlines useful
to teachers looking for experiments that teach gravitropism. The time-lapse
movies are definitely worth checking out, even if you are an expert
in the field! More...
