Extracellular ATP: an unexpected role as a signaler in plants.
ATP and other nucleoside triphosphates not only drive energy-dependent reactions inside cells, but can also function outside the plasma membrane in the extracellular matrix, where they function as agonists that can induce diverse physiological responses without being hydrolyzed. This external role of ATP is well established in animal cells but only recently has it become apparent that extracellular ATP (eATP) can also function as a signaling agent in plants. Recent data have shown that eATP and other nucleotides can induce an increase in the cytosolic Ca(2+) concentration and diverse downstream changes that influence plant growth and defense responses. Ectoapyrase enzymes that regulate the eATP concentration also have an impact on plant growth. These results beg the question of whether there is a receptor that can bind to eATP and transduce this into signaling changes. Answering this will be key to understanding how eATP and ectoapyrases influence plant growth and development.
Roux
Stanley J
SJ
Section of Molecular Cell & Developmental Biology, The University of Texas at Austin, Austin, TX 78712, USA. Electronic address: sroux@uts.cc.utexas.edu.
Steinebrunner
Iris
I
Section of Molecular Biotechnology, Technical University of Dresden, 01069 Dresden, Germany.
D000255:Adenosine Triphosphate / Q000378:metabolism*; D002118:Calcium / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology*; D018521:Plant Physiological Phenomena; D018517:Plant Roots / Q000502:physiology; D011983:Receptors, Purinergic / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
D011983:Receptors, Purinergic; D000255:Adenosine Triphosphate; D002118:Calcium