Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Evolutionary implications of C-3-C-4 intermediates in the grass Alloteropsis semialata
AU - Lundgren, Marjorie R.
AU - Christin, Pascal-Antoine
AU - Ripley, Brad S.
AU - Escobar, Emmanuel Gonzalez
AU - Besnard, Guillaume
AU - Long, Christine M.
AU - Hattersley, Paul W.
AU - Ellis, Roger P.
AU - Leegood, Richard C.
AU - Osborne, Colin P.
PY - 2016/9
Y1 - 2016/9
N2 - C-4 photosynthesis is a complex trait resulting from a series of anatomical and biochemical modifications to the ancestral C-3 pathway. It is thought to evolve in a stepwise manner, creating intermediates with different combinations of C-4-like components. Determining the adaptive value of these components is key to understanding how C-4 photosynthesis can gradually assemble through natural selection. Here, we decompose the photosynthetic phenotypes of numerous individuals of the grass Alloteropsis semialata, the only species known to include both C-3 and C-4 genotypes. Analyses of C-13, physiology and leaf anatomy demonstrate for the first time the existence of physiological C-3-C-4 intermediate individuals in the species. Based on previous phylogenetic analyses, the C-3-C-4 individuals are not hybrids between the C-3 and C-4 genotypes analysed, but instead belong to a distinct genetic lineage, and might have given rise to C-4 descendants. C(3)A. semialata, present in colder climates, likely represents a reversal from a C-3-C-4 intermediate state, indicating that, unlike C-4 photosynthesis, evolution of the C-3-C-4 phenotype is not irreversible.
AB - C-4 photosynthesis is a complex trait resulting from a series of anatomical and biochemical modifications to the ancestral C-3 pathway. It is thought to evolve in a stepwise manner, creating intermediates with different combinations of C-4-like components. Determining the adaptive value of these components is key to understanding how C-4 photosynthesis can gradually assemble through natural selection. Here, we decompose the photosynthetic phenotypes of numerous individuals of the grass Alloteropsis semialata, the only species known to include both C-3 and C-4 genotypes. Analyses of C-13, physiology and leaf anatomy demonstrate for the first time the existence of physiological C-3-C-4 intermediate individuals in the species. Based on previous phylogenetic analyses, the C-3-C-4 individuals are not hybrids between the C-3 and C-4 genotypes analysed, but instead belong to a distinct genetic lineage, and might have given rise to C-4 descendants. C(3)A. semialata, present in colder climates, likely represents a reversal from a C-3-C-4 intermediate state, indicating that, unlike C-4 photosynthesis, evolution of the C-3-C-4 phenotype is not irreversible.
KW - C-3-C-4
KW - C-2 metabolism
KW - CO2 compensation point
KW - complex trait
KW - grasses
KW - oxygen inhibition
KW - photorespiration
KW - stable isotopes
KW - CARBON-ISOTOPE DISCRIMINATION
KW - C-4 PHOTOSYNTHESIS
KW - LEAF ANATOMY
KW - FLAVERIA
KW - PHOTORESPIRATION
KW - LEAVES
KW - KRANZ
KW - ULTRASTRUCTURE
KW - METABOLISM
KW - RESPONSES
U2 - 10.1111/pce.12665
DO - 10.1111/pce.12665
M3 - Journal article
VL - 39
SP - 1874
EP - 1885
JO - Plant, Cell and Environment
JF - Plant, Cell and Environment
SN - 0140-7791
IS - 9
ER -