Cover -- THE EVOLUTION OF PLANT PHYSIOLOGY: From whole plants to ecosystems -- Contents -- List of contributors -- Preface -- The origins of plant physiology -- Evolution of plant physiology from the molecular level -- Evolution of anatomical physiology -- Evolution of environmental and ecosystem physiology -- Part I The Origins of Plant Physiology -- 1 Turning the land green: inferring photosynthetic physiology and diffusive limitations in early bryophytes -- Introduction -- Phylogeny of bryophytes -- Rubisco: a discriminating marker for photosynthetic metabolism -- Life on land: caught in a compromising situation -- Why is there no biophysical CCM in terrestrial plants other than hornworts? -- Comparative physiology of bryophyte photosynthesis -- Conclusions -- Acknowledgements -- References -- 2 Physiological evolution of lower embryophytes: adaptations to the terrestrial environment -- Introduction -- The ancestors of embryophytes -- Water, carbon dioxide and energetics of land plants -- Desiccation tolerance, desiccation intolerance, poikilohydry and homoiohydry -- Poikilohydry of algae and early-evolving embryophytes -- Desiccation tolerance and intolerance -- Evolution of homoiohydry -- History of physiological interpretations of early embryophytes -- Introduction -- Transpiration rate and endodermal function in regulating nutrient supply to the shoot -- Mechanism of endohydric water movement -- Role of stomata in determining the rate of photosynthesis and the water cost of photosynthesis -- Conclusions -- Acknowledgements -- References -- 3 Origin, function and development of the spore wall in early land plants -- Introduction -- Origin of the spore wall -- Function of the spore wall -- Spore wall development -- Basic mechanisms of spore wall formation -- Substructural organization of spore walls -- Spore wall formation in extant plants.

Spore wall formation in early land plants -- Molecular genetics of spore wall development -- Conclusions -- Acknowledgements -- References -- Part II Evolution of Plant Physiology from the Molecular Level -- 4 The evolution of plant biochemistry and the implications for physiology -- Introduction -- Molecular evolution, biochemical evolution and metabolic evolution - hierarchical terms -- Metabolic evolution - what determines whether a new enzyme is retained? -- Biomolecular activity - the evolution of 'secondary metabolism' -- Molecules retained because of their physicochemical properties -- Primary metabolism - canalized metabolism, each step depending on other pre-existing metabolic capabilities -- Selection for different molecular properties has consequences for metabolic evolution -- Biochemical evolution and physiology -- The interaction of plants with other organisms -- The human experience -- Plant/microbe and plant/insect interactions -- The evolution of regulatory systems for secondary metabolism -- A speculative scenario for the evolution of the control of pathways leading to compounds retained because they possess biomolecular activity -- Signalling molecules within plants -- The link between secondary metabolism and hormonal control -- Are plant hormones 'secondary metabolites'? -- Gibberellin synthesis - generating diversity? -- Plant hormone degradation - another role? -- Summary -- Acknowledgements -- References -- 5 Did auxin play a crucial role in the evolution of novel body plans during the Late Silurian-Early Devonian radiation of land plants? -- Introduction -- Brief overview of Cambrian radiation of bilateral animals -- Rapid diversification of animal phyla -- Characteristic body plan of each phylum -- Early establishment of body plan -- Altered expression of embryonic genes resulting in new body plans.

Silurian-Devonian radiation of land plants -- Did early land plants diverge in a rapid evolutionary radiation? -- Are the characteristic body plans of land plants established during embryonic development? -- What developmental mechanisms act to generate plant body plans? -- Did major changes in auxin regulation occur prior to the Silurian-Devonian radiation? -- Conclusions -- Acknowledgements -- References -- 6 Aquaporins: structure, function and phylogenetic analysis -- Introduction -- Transport of water across cell membranes -- Discovery of aquaporins and the MIP-family -- Structure and function of MIPs -- MIPs of bacteria, fungi and animals -- Plant MIPs -- Phylogenetic analysis -- Acknowledgement -- References -- 7 Evolutionary origin of the ethylene biosynthesis pathway in angiosperms -- Introduction -- Evolution of the angiosperm ethylene biosynthesis pathway -- Early responses to stress conditions -- The role of ACC -- The acquisition of ACC oxidase -- How ACC oxidase originated -- ACC oxidase as a 2-oxoacid-dependent dioxygenase -- Molecular changes -- The enzyme ancestral to ACC oxidase -- When did the ethylene biosynthesis pathway arise? -- Palaeoclimatic considerations -- Acknowledgements -- References -- 8 Structural biomacromolecules in plants: what can be learnt from the fossil record? -- Introduction -- Characterizing resistant biomacromolecules -- Resistant biomacromolecules in outer coverings -- Algal cell walls -- Pollen and spore walls -- Higher land plant leaf and stem cuticles -- Inner structural entities -- Water-conducting and strengthening tissues -- Conclusions -- References -- 9 Early land plant adaptations to terrestrial stress: a focus on phenolics -- Introduction -- Materials and techniques -- Trait mapping -- Thioacidolysis -- Qualitative and quantitative assessment of acid hydrolysis-resistant biomass.

Fluorescence, scanning and transmission electron microscopy -- Global estimates of early Palaeozoic resistant and sequestered carbon -- Results -- Discussion -- Conclusions -- Acknowledgements -- References -- Appendix 9.1 Physiological traits related to early stress adaptation in land plants -- 10 Plant cuticles: multifunctional interfaces between plant and environment -- Introduction -- The multifunctional interface -- Transport properties of plant cuticles -- Organic non-electrolytes -- Water -- Ions -- Wax movement: a simple solution? -- 'Pores' or 'microchannels' -- Lipid transfer proteins -- Wax transport via diffusion -- Interactions with the biotic and abiotic environment -- Water repellency and self-cleaning property -- Water repellency -- Influence of biotic and non-biotic factors on water repellency -- Self-cleaning property: the 'lotus-effect' -- Biomechanical properties -- Acknowledgements -- References -- Part III Evolution of Anatomical Physiology -- 11 Falling atmospheric CO[sub(2)] - the key to megaphyll leaf origins -- Introduction -- A mechanism coupling Devonian megaphyll evolution with falling CO[sub(2)]2 -- Early evolution of the megaphyll leaf -- Quantifying the trends in early megaphyll leaf evolution -- Discussion -- Acknowledgements -- References -- 12 Stomatal function and physiology -- Introduction -- Stomatal control of leaf gas exchange -- Role of stomata in leaf gas exchange -- Heterogeneity in stomatal characters -- Effect of environmental variables on stomata and photosynthesis -- Stomatal response to CO[sub(2)] -- Stomatal response to humidity -- Stomatal response to light -- Environmental interactions and stomatal responses -- Modern techniques for ecophysiological stomatal research -- Evolutionary context -- Conclusion -- Acknowledgements -- References.

13 The photosynthesis-transpiration compromise and other aspects of leaf morphology and leaf functioning within an evolutionary and ecological context of changes in… -- Introduction -- 'Trade-off' between photosynthesis and transpiration -- Desert plants -- Stomatal response to atmospheric CO[sub(2)] -- Analysis of the 'trade-off' response within a broader context -- Modern Mediterranean ecosystems -- Dry season -- Wet season -- Prevention of wetting of leaves by rain and facilitation of drying -- Dripping tip of leaves and position of the leaf -- Wettability of leaves -- Avoidance of direct contact between water film and stomata: effect of a hair layer and stomatal wax plugs -- Further ecological consequences: effect of fungal leaf pathogens and ion leaching -- Drying of wet leaves by evaporation -- Formulation of the rate of drying of a wet surface -- Ecological consequences of leaf morphology on the rate of drying of wet leaves -- Adaptive changes in leaf morphology in relation to the 'trade-off' between photosynthesis and transpiration -- Final remarks -- Acknowledgements -- References -- 14 Xylem hydraulics and angiosperm success: a test using broad-leafed species -- Introduction -- Materials and methods -- Choice of species -- Physiological studies -- Water relations -- Photosynthesis studies -- Results -- Discussion -- References -- 15 Evolution of xylem physiology -- Introduction -- 'Trade-off' triangle -- Early beginnings -- Distribution of wood anatomical features -- Vessel element perforations -- Diameter, density and length of vessels -- Ecological preferences in modern woods -- Type 1 -- Type 2 -- Type 3 -- Type 4 -- Type 5 -- Geological record -- Experimental work -- Conductive efficiency versus vulnerability to embolism -- Conductive efficiency versus mechanical strength -- Cohesion-tension theory and sap ascent.

Mechanical strength, implosion resistance and resistance to embolism.