Thermal acclimation of leaf and root respiration: an investigation comparing inherently fast‐ and slow‐growing plant species

Abstract

We investigated the extent to which leaf and root respiration (R) differ in their response to short‐ and long‐term changes in temperature in several contrasting plant species (herbs, grasses, shrubs and trees) that differ in inherent relative growth rate (RGR, increase in mass per unit starting mass and time). Two experiments were conducted using hydroponically grown plants. In the long‐term (LT) acclimation experiment, 16 species were grown at constant 18, 23 and 28 °C. In the short‐term (ST) acclimation experiment, 9 of those species were grown at 25/20 °C (day/night) and then shifted to a 15/10 °C for 7 days. Short‐term Q10 values (proportional change in R per 10 °C) and the degree of acclimation to longer‐term changes in temperature were compared. The effect of growth temperature on root and leaf soluble sugar and nitrogen concentrations was examined. Light‐saturated photosynthesis (Asat) was also measured in the LT acclimation experiment. Our results show that Q10 values and the degree of acclimation are highly variable amongst species and that roots exhibit lower Q10 values than leaves over the 15–25 °C measurement temperature range. Differences in RGR or concentrations of soluble sugars/nitrogen could not account for the inter‐specific differences in the Q10 or degree of acclimation. There were no systematic differences in the ability of roots and leaves to acclimate when plants developed under contrasting temperatures (LT acclimation). However, acclimation was greater in both leaves and roots that developed at the growth temperature (LT acclimation) than in pre‐existing leaves and roots shifted from one temperature to another (ST acclimation). The balance between leaf R and Asat was maintained in plants grown at different temperatures, regardless of their inherent relative growth rate. We conclude that there is tight coupling between the respiratory acclimation and the temperature under which leaves and roots developed and that acclimation plays an important role in determining the relationship between respiration and photosynthesis.

Respiration of turions and winter apices in aquatic carnivorous plants

“…Q 10 values found in turions (Table 1) are comparable with those reported for leaves of dozens of terrestrial herb or tree species (Atkin & Tjoelker 2003;Loveys et al 2003) and Fontinalis shoots (Maberly 1985). However, a great variation of both R D and Q 10 values for different batches of turions of Aldrovanda and U. australis at the same developmental state follows from the comparison of the data in Table 1 with those published by Adamec (2003a).…”

“…The same conclusion was also made by Loveys et al (2003) who did not find any correlations between foliar respiration Q 10 and some physiological traits as plant growth rate, leaf sugar or nitrogen content in herbs. In both dormancy states and at both temperatures, relatively high R D was found in Hydrocharis, Aldrovanda, and Caldesia (Table 1).…”

Photosynthesis and dark respiration of leaves of terrestrial carnivorous plants

“…R D and its proportion to P Nmax The mean R D values in leaves and traps of CPs in Table 1 were about by one-third lower than those reported by Loveys et al (2003) for leaves of 16 plant species of all functional groups (mean about 35, range 15-100 nmol CO 2 g −1 s −1 ) at 23…”

A dynamic global vegetation model for studies of the coupled atmosphere‐biosphere system

“…To overcome this problem, the slope of the temperature dependence of the maintenance coefficient (and some other parameters, such as critical temperature values for the phenological cycle) for this PFT is parameterized as a function of a reference temperature T ref at the given grid point. Note that thermal acclimation of autotrophic respiration has actually been observed for a number of different plant functional types, not only for C 3 grasses [Loveys et al, 2003]. When the vegetation distribution is calculated dynamically, T ref is actually the (simulated) multiannual mean temperature (with an integration constant of several years; see section 2.1).…”