Leaf respiration and alternative oxidase in field-grown alpine grasses respond to natural changes in temperature and light.
• We report the first investigation of changes in electron partitioning via the alternative respiratory pathway (AP) and alternative oxidase (AOX) protein abundance in field-grown plants and their role in seasonal acclimation of respiration. • We sampled two alpine grasses native to New Zealand, Chionochloa rubra and Chionochloa pallens, from field sites of different altitudes, over 1 yr and also intensively over a 2-wk period. • In both species, respiration acclimated to seasonal changes in temperature through changes in basal capacity (R₁₀) but not temperature sensitivity (E₀). In C. pallens, acclimation of respiration may be associated with a higher AOX : cytochrome c oxidase (COX) protein abundance ratio. Oxygen isotope discrimination (D), which reflects relative changes in AP electron partitioning, correlated positively with daily integrated photosynthetically active radiation (PAR) in both species over seasonal timescales. Respiratory parameters, the AOX : COX protein ratio and D were stable over a 2-wk period, during which significant temperature changes were experienced in the field. • We conclude that respiration in Chionochloa spp. acclimates strongly to seasonal, but not to short-term, temperature variation. Alternative oxidase appears to be involved in the plant response to both seasonal changes in temperature and daily changes in light, highlighting the complexity of the function of AOX in the field.
School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
Stephanie Y
SY
Searle
Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA.
Samuel
S
Thomas
Lamont-Doherty Earth Observatory, Columbia University, New York, NY 10027, USA.
Kevin L
KL
Griffin
School of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
Travis
T
Horton
School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
Ari
A
Kornfeld
Department of Environmental Science and Energy Research, Weizmann Institute of Science, Rehovot 76100, Israel.
Dan
D
Yakir
Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-901 87 Umeå, Sweden.
Vaughan
V
Hurry
School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
Matthew H
MH
Turnbull
D000383:Agriculture; D019069:Cell Respiration / Q000528:radiation effects; D017753:Ecosystem; D003576:Electron Transport Complex IV / Q000378:metabolism; D008027:Light; D016014:Linear Models; D024101:Mitochondrial Proteins; D010088:Oxidoreductases / Q000378:metabolism*; D010103:Oxygen Isotopes; D018515:Plant Leaves / Q000166:cytology / Q000201:enzymology* / Q000528:radiation effects; D010940:Plant Proteins; D006109:Poaceae / Q000201:enzymology* / Q000254:growth & development* / Q000528:radiation effects; D011891:Rain; D012621:Seasons; D013696:Temperature; D013997:Time Factors; D000099188:Alternative Oxidase
D003576:Electron Transport Complex IV; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010103:Oxygen Isotopes; D010940:Plant Proteins; D000099188:Alternative Oxidase