Abstract

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 (R(10)) but not temperature sensitivity (E(0)). 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.

Keywords

acclimation; alternative oxidase (AOX); Chionochloa; cytochrome oxidase; leaf respiration; oxygen isotope discrimination; photosynthetically active radiation (PAR); seasonal variation

Published in

New Phytologist
2011, Volume: 189, number: 4, pages: 1027-1039
Publisher: WILEY-BLACKWELL

UKÄ Subject classification

Botany


Publication identifier

DOI: https://doi.org/10.1111/j.1469-8137.2010.03557.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/76334