Atkin, O.K., Scheurwater, I. and Pons, T.L. (2007) Respiration as a percentage of daily photosynthesis in whole plants is homeostatic at moderate, but not high, growth temperatures. New Phytologist, 174 (2). pp. 367-380. ISSN 0028-646X
• Here, we investigated the impact of temperature on the carbon economy of two Plantago species from contrasting habitats.
• The lowland Plantago major and the alpine Plantago euryphylla were grown hydroponically at three constant temperatures: 13, 20 and 27°C. Rates of photosynthetic CO2 uptake (P) and respiratory CO2 release (R) in shoots and R in roots were measured at the growth temperature using intact plants. At each growth temperature, air temperatures were changed to establish short-term temperature effects on the ratio of R to P (R/P).
• In both species, R/P was essentially constant in plants grown at 13 and 20°C. However, R/P was substantially greater in 27°C-grown plants, particularly in P. euryphylla. The increase in R/P at 27°C would have been even greater had biomass allocation to roots not decreased with increasing growth temperature. Short-term increases in air temperature increased R/P in both species, with the effects of air temperature being most pronounced in 13°C-grown plants.
• We conclude that temperature-mediated changes in biomass allocation play an important role in determining whole-plant R/P values, and, while homeostasis of R/P is achieved across moderate growth temperatures, homeostasis is not maintained when plants are exposed to growth temperatures higher than usually experienced in the natural habitat.
|Copyright, Publisher and Additional Information:||Open access copy available from the journal web site.|
|Keywords:||acclimation; biomass allocation; CO2; Plantago; photosynthesis; respiration; temperature|
|Institution:||The University of York|
|Academic Units:||The University of York > Biology (York)|
|Depositing User:||Open Access From Journal|
|Date Deposited:||23 Dec 2008 13:47|
|Last Modified:||23 Dec 2008 13:47|