Watertransport in plants at multiple scales: A physiological, ecological, andevolutionary appraisal
Bauerle, Taryn .
Fine root spatial and temporal dynamics under limited soil moisture.
Linkages between plant growth rate and root responses to soil moisture heterogeneity were investigated using a model Vitis system where genetically identical shoots were grafted to genetically diverse root systems Fast- and slow-growing root systems were found to respond differently to low resource availability such as water, making it difficult to accurately determine root to shoot proliferation strategies. Indeed response differences in two root systems that differ in their potential growth rate offers support for the hypothesis that root production and partitioning between wet and dry soil are specific responses to localized soil moisture. We were unable to find any differences in tolerance of dry soil between the two root systems as demonstrated by the similarity in root lifespan between both root systems. Overall not only do results contribute to our understanding of the diverse root foraging responses to heterogeneous soil moisture that may occur in ecological communities but adds to our understanding of the theories behind the potential growth rate of plants.Based on root dynamics results the potential importance of hydraulic redistribution on similar lifespans of roots in wet and dry soil was recognized. While the idea that roots in wet soil support those in dry soil seems somewhat intuitive this study was the first to demonstrate the importance of internal movement of water on root survivorship,and viability. By placing plants under24-hrs of illumination internal hydraulic redistribution was prohibited thus preventing roots in dry soil from rehydrating at night which resulted in reduced root turgor, increased electrolyte leakage, rapidly declining root water potentials and ultimately rapid death of roots in the dry soil.
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1 - Cornell University, Horticulture, 134A Plant Science Bldg., Ithaca, NY, 14853, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Delaware C/Hyatt
Date: Monday, July 9th, 2012
Time: 1:45 PM