Greg Clark

Cell Signaling part of CUREnet:CURE Collection
A recent exciting discovery in plants is that ATP is released into the extracellular matrix where it plays a major role in regulating growth and development. Extracellular ATP (eATP) has been confirmed to act as a hormone in animal cells, where it rapidly induces an increase in cytoplasmic calcium levels, a change that commonly leads to the activation of signaling pathways that greatly influence cell activities in both plants and animals. There is a biphasic growth response to applied ATP in growing plant cells and tissues suggesting that eATP functions like a hormone in plants as it does in animals. Students in this CURE carry out novel experiments on how eATP controls plant growth. They learn methods of experimental design, data gathering, data interpretation, and data presentation, and they learn principles of stimulus-response coupling that apply equally well to animals and plants. Students use the model plant, Arabidopsis. They to do their experiments on extracellular ATP signaling in root hairs, an agriculturally important model system for studying plant growth. Specifically, this CURE addresses the question of what are the early signaling steps that mediate the effects of eATP on the polarized growth of single-celled root hairs, structures that are crucial for plants' absorption of water and nutrients from the soil. Their experiments constitute a novel test of the signaling steps required for eATP-mediated changes in root hair growth.