Regulation of root respiration in two species of Plantago that differ in relative growth rate: the effect of short‐ and long‐term changes in temperature

Abstract

This study investigates the effect of short-and long-term changes in temperature on the regulation of root respiratory O 2 uptake by substrate supply, adenylate restriction and/or the capacity of the respiratory system. The species investigated were the lowland Plantago lanceolata L. and alpine Plantago euryphylla Briggs , Carolin & Pulley, which are inherently fast-and slow-growing, respectively. The plants were grown hydroponically in a controlled environment (constant 23 ∞ ∞ ∞ ∞ C). The effect of long-term exposure to low temperature on regulation of respiration was also assessed in P. lanceolata using plants transferred to 15/ 10 ∞ ∞ ∞ ∞ C (day/night) for 7 d. Exogenous glucose and uncoupler (CCCP) were used to assess the extent to which respiration rates were limited by substrate supply and adenylates. The results suggest that adenylates and/or substrate supply exert the greatest control over respiration at moderate temperatures (e.g. 15-30 ∞ ∞ ∞ ∞ C) in both species. At low temperatures (5-15 ∞ ∞ ∞ ∞ C), CCCP and glucose had little effect on respiration, suggesting that respiration was limited by enzyme capacity alone. The Q 10 (proportional increase of respiration per 10 ∞ ∞ ∞ ∞ C) of respiration was increased following the addition of CCCP and/or exogenous glucose. The degree of stimulation by CCCP was considerably lower in P. euryphylla than P. lanceolata . This suggests that respiration rates operate much closer to the maximum capacity in P. euryphylla than P. lanceolata . When P. lanceolata was transferred to 15 ∞ ∞ ∞ ∞ C for 7 d, respiration acclimated to the lower growth temperature (as demonstrated by an increase in respiration rates measured at 25 ∞ ∞ ∞ ∞ C). In addition, the Q 10 was higher, and the stimulatory effect of exogenous glucose and CCCP lower, in the cold-acclimated roots in comparison with their warm-grown counterparts. Acclimation of P. lanceolata to different day/night-time temperature regimes was also investigated. The low nighttime temperature was found to be the most important factor influencing acclimation. The Q 10 values were also higher in plants exposed to the lowest night-time temperature. The results demonstrate that short-and long-term changes in temperature alter the importance of substrate supply, adenylates and capacity of respiratory enzymes in regulating respiratory flux.

A Genome-Scale Metabolic Model Accurately Predicts Fluxes in Central Carbon Metabolism under Stress Conditions

“…At high temperature, 82% of the total CO 2 released was from respiration. The response of plant respiration to temperature is known to be acclimative, with acclimation occurring within 1 to 2 d of growth at the elevated temperature (Covey-Crump et al, 2002). Acclimation is not apparent after 6 d of growth of the cell suspension culture, which is consistent with acclimation involving tissue-level morphological and cellular changes (Armstrong et al, 2006) that are unlikely to be replicated in a cell culture.…”

The hot and the cold: unravelling the variable response of plant respiration to temperature

“…1, where exposure of a warm-grown plant to the cold for several days results in an increase in the rate of R at a common measurement temperature (Rook 1969;Chabot and Billings 1972;Pisek et al 1973;Larigauderie and Körner 1995;Körner 1999;Atkin et al 2000b;Covey-Crump et al 2002;Zha et al 2002Zha et al , 2005Bolstad et al 2003). Conversely, exposure to high temperatures results in a decrease in the rate of R at a common temperature (Fig.…”

“…In contrast, measurements of R in roots are made using whole root systems (e.g. Smakman and Hofstra 1982;Bouma et al 1997;Covey-Crump et al 2002;Loveys et al 2003) or root segments of differing age or function (e.g. Higgins and Spomer 1976;Crawford and Palin 1981;Sowell and Spomer 1986;Weger and Guy 1991;Zogg et al 1996;Pregitzer et al 1997Pregitzer et al , 1998Burton et al 2002;Comas and Eissenstat 2004).…”

“…Growth-temperature effects on Q 10 also appear to differ between plants exposed to a new thermal regime for several days and leaves and roots that develop under contrasting temperatures. Covey-Crump et al (2002) found that the Q 10 (between 15-23 • C) of Plantago lanceolata root R was greater at low measurement temperatures in plants exposed to 15 • C for 7 d than in plants kept at 23 • C. Similarly, Rook (1969) found that the Q 10 (between 15-30 • C) of leaf R in Pinus radiata seedlings grown at 33 / 28 • C increased following a 2-d exposure to 15 / 10 • C (rates of R measured at 15-30 • C increased significantly, whereas there was no change in R measured at 8 • C). Conversely, shifting of 15 / 10 • C grown plants to 33 / 28 • C resulted in the Q 10 decreasing within 2 d (again, no change in R at 8 • C was observed).…”

Modelling temperature acclimation effects on the carbon dynamics of forest ecosystems in the conterminous United States

“…Kattge and Knorr (2007) further derived a general formulation for quantifying the temperature acclimation effect in the parameters established by Farquhar photosynthesis models. Apart from photosynthesis, studies on the response of plant respiration to temperature have shown that increasing temperature may cause a decline of the Q10, the rate of change in respiration due to a 108C increase in temperature, leading to lower plant respirations (Wager, 1941;Atkin et al, 2000a;Atkin et al, 2000b;Tjoelker et al, 2001;Covey-Crump et al, 2002;Loveys et al, 2003). This refers to Type I acclimation as proposed by Atkin and Tjoelker (2003) and Atkin et al (2005).…”