Related Experiment Video
Updated: Jun 5, 2026

Relating Stomatal Conductance to Leaf Functional Traits
Published on: October 12, 2015
Seasonal variation of leaf respiration and the alternative pathway in field-grown Populus × canadensis
Stephanie Y Searle1, Matthew H Turnbull
1School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand. stephanieysearle@gmail.com
Abstract:
The temperature response of plant respiration varies between species and can acclimate to changing temperatures. Mitochondrial respiration in plants has two terminal oxidases: the cytochrome c oxidase (COX) and the cyanide-resistant alternative oxidase (AOX). In Populus × canadensis var. italica, a deciduous tree species, we investigated the temperature response of leaf respiration via the alternative and cytochrome pathways, as well as seasonal changes in these pathways, using the oxygen isotope fractionation technique. The electron partitioning through the alternative pathway (τ(a) ) increased from 0 to 30-40% with measurement temperatures from 6 to 30°C at all times measured throughout the growing season. τ(a) at the growth temperature (the average temperature during 3 days prior to sampling) increased from 12 to 29% from spring until late summer and decreased thereafter. Total respiration declined throughout the growing season by 50%, concomitantly with decreases in both AOX (64%) and COX (32%) protein abundances. Our results provide new insight into the natural variability of AOX protein abundances and alternative respiration electron partitioning over immediate and seasonal timescales.
More Related Videos
11:31High-throughput Screening of Recalcitrance Variations in Lignocellulosic Biomass: Total Lignin, Lignin Monomers, and Enzymatic Sugar Release
Published on: September 15, 2015
09:31In Vivo Leaf Inoculation: An Alternative Method to Assess the Disease Resistance of Hybrid Clones in Poplar Breeding of Stem Canker Disease
Published on: September 20, 2024
Related Concept Videos
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
The Calvin Benson Cycle
Regulation of Transpiration by Stomata
Adaptations that Reduce Water Loss
Chemical Factors Affecting Respiration Centers
CO2 has a potent influence on respiration and is strictly regulated. Under...
Biological Clocks and Seasonal Responses