Participants On This Publication
Organisms In This Publication
Journal of Experimental Botany, 2006      Root respiratory characteristics associated with plant adaptation to high soil temperature for geothermal and turf-type Agrostis species
Shimon Rachmilevitch, Hans Lambers and Bingru Huang
Journal of Experimental Botany, 2006

Respiration is a major avenue of carbohydrates loss. The objective of the present study was to examine root respiratory characteristics associated with root tolerance to high soil temperature for two Agrostis species: thermal Agrostis scabra, a species adapted to high temperature soils in geothermal areas in Yellowstone National Park, and two cultivars ('L-93' and 'Penncross') of a cool-season turfgrass species, A. stolonifera (creeping bentgrass), that differ in their heat sensitivity. Roots of thermal A. scabra and both creeping bentgrass cultivars were exposed to high (37 °C) or low soil temperature (20 °C). Total root respiration rate and specific respiratory costs for maintenance and ion uptake increased with increasing soil temperatures in both species. The increases in root respiratory rate and costs for maintenance and ion uptake were less pronounced for A. scabra than for both creeping bentgrass cultivars (e.g. respiration rate increased by 50% for A. scabra upon exposure to high temperature for 28 d, as compared with 99% and 107% in 'L-93' and 'Penncross', respectively). Roots of A. scabra exhibited higher tolerance to high soil temperature than creeping bentgrass, as manifested by smaller decreases in relative growth rate, cell membrane stability, maximum root length, and nitrate uptake under high soil temperature. The results suggest that acclimation of respiratory carbon metabolism plays an important role in root survival of Agrostis species under high soil temperatures, particularly for the thermal grass adaptation to chronically high soil temperatures. The ability of roots to tolerate high soil temperatures could be related to the capacity to control respiratory rates and increase respiratory efficiency by lowering maintenance and ion uptake costs. Key words: Agrostis, heat tolerance, root respiration, specific respiratory costs.

NOTE: the article text supplied here is for educational purposes only.
*Don't have Adobe Reader? Get the latest version.

NOTE: Some versions of Adobe Reader have problems with Google Chrome. Either resize the browser to view the paper or enable the Chrome internal PDF viewer by entering chrome://plugins in your address bar and clicking enable for the Chrome PDF Viewer plugin.