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The evolutionary ecology of C 4 plants
Author(s) -
Christin PascalAntoine,
Osborne Colin P.
Publication year - 2014
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13033
Subject(s) - biology , ecology , biome , ecological niche , context (archaeology) , niche , evolutionary physiology , diversification (marketing strategy) , phylogenetic tree , evolutionary ecology , functional ecology , convergent evolution , evolutionary biology , adaptation (eye) , plant evolution , ecosystem , habitat , paleontology , biochemistry , marketing , neuroscience , genome , gene , business , host (biology)
Summary C 4 photosynthesis is a physiological syndrome resulting from multiple anatomical and biochemical components, which function together to increase the CO 2 concentration around Rubisco and reduce photorespiration. It evolved independently multiple times and C 4 plants now dominate many biomes, especially in the tropics and subtropics. The C 4 syndrome comes in many flavours, with numerous phenotypic realizations of C 4 physiology and diverse ecological strategies. In this work, we analyse the events that happened in a C 3 context and enabled C 4 physiology in the descendants, those that generated the C 4 physiology, and those that happened in a C 4 background and opened novel ecological niches. Throughout the manuscript, we evaluate the biochemical and physiological evidence in a phylogenetic context, which demonstrates the importance of contingency in evolutionary trajectories and shows how these constrained the realized phenotype. We then discuss the physiological innovations that allowed C 4 plants to escape these constraints for two important dimensions of the ecological niche – growth rates and distribution along climatic gradients. This review shows that a comprehensive understanding of C 4 plant ecology can be achieved by accounting for evolutionary processes spread over millions of years, including the ancestral condition, functional convergence via independent evolutionary trajectories, and physiological diversification.ContentsSummary 765 I. Introduction 765 II. Which properties are common to all C 4 plants? 767 III. What is unique to C 4 plants? 768 IV. What happened before C 4 physiology? 768 V. What happened during the transition to C 4 photosynthesis? 770 VI. What happened after C 4 evolution? 771 VII. Contingency and the ecological diversity of C 4 plants 773 VIII. Conclusions 777Acknowledgements 777References 777