Improved temperature response functions for models of Rubisco-limited photosynthesis

Abstract

Abbreviations: t, Rubisco specificity factor (dimensionless); G*, CO 2 compensation point in the absence of dark respiration (mmol mol -2 ); DH a , energy of activation (kJ mol -1 ); A, net rate of CO 2 uptake per unit leaf area (mmol m -2 s -1 ); c, scaling constant (dimensionless); C i , intercellular CO 2 concentration (mmol mol -1 ); K c , Michaelis constant for CO 2 (mmol mol -1 ); K o , Michaelis constant for O 2 (mmol mol -1 ); R, molar gas constant (kJ K -1 mol -1 ); R d , Mitochondrial respiration rate in the light (mmol m -2 s -1 ); T k , Leaf absolute temperature (K); v c , carboxylation velocity (mmol m -2 s -1 ), V c,max , maximum RuBP saturated rate of carboxylation (mmol m -2 s -1 ); v o , oxygenation velocity (mmol m -2 s -1 ); V o,max , maximum RuBP saturated rate of oxygenation (mmol m -2 s -1 ); W c , RuBP saturated rate of carboxylation (mmol m -2 s -1 ); PPFD, photosynthetically active photon flux density (mmol m -2 s -1 ).

Seasonal variations in photosynthesis, intrinsic water-use efficiency and stable isotope composition of poplar leaves in a short-rotation plantation

“…Absorptance was derived from the CCM readings according to Bauerle et al (2004) after conversion of the CCM readings to soil plant analysis development (SPAD) values (Richardson et al 2002). Mesophyll conductance was then estimated following the equation of Harley et al (1992): $g_{\mathrm{normalm}}=\frac{A}{C_{\mathrm{normali}}-\left(42.7\left(J_{\mathrm{ETR}}+8false(A+R_{\mathrm{normald}}false)\right)/\left(J_{\mathrm{ETR}}-4false(A+R_{\mathrm{normald}}false)\right)\right)},$ where 42.7 is the CO 2 compensation point in the absence of dark respiration, as taken from Bernacchi et al (2001), and R d is the mitochondrial respiration in the light, taken as half of the dark respiration obtained from the A -light curves (Piel et al 2002, Niinemets et al 2005). The values of g m were then used to convert A – C i curves to A – C c curves, with C c being the CO 2 concentration in the chloroplast stroma calculated as (Limousin et al 2010, Misson et al 2010): $C_{\mathrm{normalc}}=C_{\mathrm{normali}}-\frac{A}{g_{\mathrm{normalm}}}.$ …”

A compendium of temperature responses of Rubisco kinetic traits: variability among and within photosynthetic groups and impacts on photosynthesis modeling

“…Furthermore, at any given [CO 2 ], Rubisco catalysis is also strongly affected by temperature. In particular, the maximum carboxylase turnover rate ($k_{\text{cat}}^{\text{c}}$) of Rubisco increases up to 50–55 ºC or even higher for some organisms from extreme environments (Galmés et al , 2015 for a review), while the Rubisco specificity factor ( S c/o ) decreases and the Michaelis–Menten constants for CO 2 ( K c ) and O 2 ( K o ) increase (Bernacchi et al , 2001). Although the basic patterns of temperature-dependent variation in key Rubisco kinetic characteristics are well known and measured in a number of studies, there is surprisingly limited comparative information of the variability of temperature responses of Rubisco across different photosynthetic groups that evolved at different periods of time, as well as among photosynthetic organisms adapted to different environmental conditions.…”

“…From a practical perspective, the accuracy of the FvCB model in simulating temperature responses of leaf photosynthesis for any given species requires information on the species-specific temperature dependences of the Rubisco catalytic constants, in particular, K c , K o , S c/o (or the photosynthetic CO 2 compensation point in the absence of mitochondrial respiration, Γ*) and $k_{\text{cat}}^{\text{c}}$ (von Caemmerer, 2000; Bernacchi et al , 2001; Walker et al , 2013). Indeed, recent modeling indicates that the temperature dependence of Rubisco kinetics dictates the optimum temperature for the photosynthetic rate (Galmés et al , 2014 a ).…”

“…Indeed, recent modeling indicates that the temperature dependence of Rubisco kinetics dictates the optimum temperature for the photosynthetic rate (Galmés et al , 2014 a ). So far, application of the FvCB model to leaf photosynthesis has used three main datasets of temperature dependences of Rubisco kinetics: Badger and Collatz (1977) for Atriplex glabriuscula ( in vitro measurements, used also in the original FvCB model), Jordan and Ogren (1984) for Spinacia oleracea ( in vitro measurements) and Bernacchi et al (2001) for Nicotiana tabacum (determined from in vivo leaf gas-exchange measurements in transgenic lines with reduced Rubisco content where photosynthesis was assumed to be limited by Rubisco under all [CO 2 ] and leaf temperature combinations). These three datasets are widely used in modeling photosynthesis of species, plant stands, landscapes and biomes, whereas the use of any one of the three datasets mainly reflects the historical roots of the given modeling community (e.g.…”

The short-term combined effects of temperature and organic matter enrichment on permeable coral reef carbonate sediment metabolism and dissolution

“…The bacterial communities residing in marine sediments generally display a hyperbolic temperature-production relationship where GPP increases with T (∼ +32 % per 1 • C increase) until an optimal rate is reached roughly +2-3 • C above naturally observed seasonal maxima. This T -GPP relationship then declines at higher temperatures (+4-6 • C) due to the deactivation of component reactions (Bernacchi et al, 2001). In Arctic and temperate marine sediment communities, the increase in T can alter the balance between GPP and R, with an observed shift towards net heterotrophy (GPP / R < 1; e.g.…”