Terrestrial Photosynthesis in a Changing Environment: A Molecular, Physiological, and Ecological Approach
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Understanding how photosynthesis responds to the environment is crucial for improving plant production and maintaining biodiversity in the context of global change. Covering all aspects of photosynthesis, from basic concepts to methodologies, from the organelle to whole ecosystem levels, this is an integrated guide to photosynthesis in an environmentally dynamic context. Focusing on the ecophysiology of photosynthesis - how photosynthesis varies in time and space, responds and adapts to environmental conditions and differs among species within an evolutionary context - the book features contributions from leaders in the field. The approach is interdisciplinary and the topics covered have applications for ecology, environmental sciences, agronomy, forestry and meteorology. It also addresses applied fields such as climate change, biomass and biofuel production and genetic engineering, making a valuable contribution to our understanding of the impacts of climate change on the primary productivity of the globe and on ecosystem stability.
approach are not additive (i.e., their total could be higher than 100%). By this approach, the maximum possible increase that could occur with, for example, increased conductance is determined but 112 A. DIAZ-ESPEJO ET AL. the relative effect of small increases in conductance are not determined. Jones (1992) proposed an alternative option based on the theory of control analysis that could avoid the unrealistic conditions of assuming infinite gs. The limitation to photosynthesis imposed by gs
electron-transfer pathway around PSI (CEFI). The CEFI was discovered by Arnon (1959) in isolated thylakoids but its role in vivo was questioned until optical methods (Chapter 10) allowed it to be monitored in leaves (Bukhov and Carpentier, 2004). It corresponds to the putative ferredoxinplastoquinone-reductase or FQR (Bendall and Manasse, 1995), an Â�electron-transfer activity to which no protein support could be ascribed up to now, although related mutations have been recently characterised
phloem (Fig. 2.6). Most of the carbon is converted to sucrose in the cytosol, although a number of plants make sugar alcohols such as mannitol and sorbitol. These sugars travel symplastically (through plasmodesmata) up to the veins. There is significant variation in the mechanism of loading sugars and sugar alcohols into veins. Most but not all plants use energy to concentrate sugars in the phloem, which leads to water uptake, and movement through the phloem to sink regions of the plant, where
from E. coli and spinach have different stoichiometries for the F0 subunits (10 for E. coli and 14 for spinach), but in both cases the H+/ATP ratio is four (Steigmiller etÂ€al., 2008), a value that is consistent with earlier experimental determinations of the H+/ATP ratio. In addition to the ideal ATP/H+ of the ATPase, slips and leaks in the thylakoid membrane and ATPase will decrease the ATP/H+ stoichiometry (Nelson etÂ€al., 2002). Slippage and leakage are predicted to increase as the pmf
µ is the Rd/Rn ratio. A dataset made of Rn, gm and values obtained with different AN/Ci curves allows one to get an estimate of the slope µ with a regression analysis (Fig. 4.2C). Following Cornic’s method (Cornic, 1973), an illuminated leaf is placed in CO2-free air in either N2 (0% O2) or 21% O2 and then darkened. The CO2 production rate in the light is denoted as LO (in 21% O2) or LN (in N2). As soon as the leaf is darkened, refixation of (photo)respired CO2 vanishes and one can see a peak