Premium
Impacts of drought on leaf respiration in darkness and light in Eucalyptus saligna exposed to industrial‐age atmospheric CO 2 and growth temperature
Author(s) -
Ayub Gohar,
Smith Renee A.,
Tissue David T.,
Atkin Owen K.
Publication year - 2011
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/j.1469-8137.2011.03673.x
Subject(s) - acclimatization , photosynthesis , respiration , eucalyptus , darkness , ecosystem , carbon cycle , sugar , biology , botany , rubisco , agronomy , horticulture , ecology , biochemistry
Summary• Our study assessed the impact of a wide range of industrial‐age climate scenarios on leaf respiration ( R ) in Eucalyptus saligna . • Well‐watered or sustained drought‐treated plants were grown in glasshouses differing in atmospheric CO 2 concentration ([CO 2 ]) (280, 400 and 640 μl l −1 ) and temperature (26 and 30°C). Rates of R in darkness ( R dark ) and light ( R light ), photosynthesis ( A ) and related leaf traits (mass : area relationships, and nitrogen, phosphorus, starch and sugar concentrations) were measured. • Light inhibited R in all cases ( R light < R dark ) (well‐watered: 40%; drought‐treated: 73%). Growth [CO 2 ] and temperature had little impact on area‐based rates of R dark or R light , with R light exhibiting minimal thermal acclimation. By contrast, sustained drought resulted in reduced R dark , R light and A , with the inhibitory effect of drought on A and R light ( c. 50–70%) greater than that on R dark ( c. 15%). Drought effects were fully reversible after watering. Variability in R light appeared to be dependent on the underlying rate of R dark and associated Rubisco activity. • Collectively, our data suggest that there is an asynchronous response of leaf carbon metabolism to drought, and a tighter coupling between R light and A than between R dark and A , under both past and future climate scenarios. These findings have important implications for ecosystem/global models seeking to predict carbon cycling.