| Abstract Detail
Environmental Physiology Ortega, Joseph K.E. [1], Ortega, Elena L. [2], Scott, Morgan A. [3]. Turgor pressure may mediate two negative growth responses of the sporangiophores of Phycomyces blakesleeanus. Many investigators that are interested in sensory transduction have studied the sensory responses of the sporangiophores of Phycomyces blakesleeanus. The sporangiophore can sense a variety of environmental signals and respond to them with a change in growth direction (tropic responses) or a transient change in elongation growth rate (growth responses). Two stimuli that elicit a transient decrease in elongation growth rate (negative growth response) are the initiation of airflow around the stalk (wind growth response) and a decrease in oxygen concentration in the surrounding air. Many investigators have studied the wind growth response over several decades and there is still no consensus as to how the sporangiophore senses the onset of airflow. Also the changes in oxygen concentration that elicit the negative growth response are above saturation for respiration, so respiration is not affected. Overall, the methods by which the sporangiophore detects these stimuli are unknown. In the present study, the turgor pressure was measured with a pressure probe before and after the onset of airflow around the stalk, and before and after a reduction in oxygen concentration in the surrounding air. A small decrease in turgor pressure was measured immediately after the onset of the airflow and immediately after the decrease in oxygen concentration. The results suggest that a decrease in turgor pressure mediates both negative growth responses and may be the stimulus for these two negative growth responses. Log in to add this item to your schedule
1 - University of Colorado at Denver and Health Science Center, Mechanical Engineering, Bioengineering Laboratory, Campus Box 112, PO Box 173364, Denver, CO, 80217-3364, USA 2 - University of Colorado at Denver and Health Science Center, Mathematics 3 - University of Colorado at Denver and Health Science Center, Mechanical Engineering
Keywords: sensory responses Phycomyces blakesleeanus wind growth response cell growth regulation.
Presentation Type: Plant Biology Abstract Session: P Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton Date: Sunday, July 8th, 2007 Time: 8:00 AM Number: P01025 Abstract ID:1250 |