Research output: Contribution to Journal/Magazine › Journal article
Research output: Contribution to Journal/Magazine › Journal article
}
TY - JOUR
T1 - The influence of elevated C02 on growth and age-related changes in leaf gas exchange.
AU - Pearson, Mark
AU - Brooks, Georgina L.
PY - 1995
Y1 - 1995
N2 - Rumex obtusifolius plants were grown for several months in daylit environment chambers (Solardomes) force-ventilated with air containing 350 or 600 µ;mol mol–1 C02. Elevated CO2 was found to accelerate the natural ontogenic decline in photosynthesis, but did not reduce leaf duration. In both CO2 treatments photosynthetic rates declined progressively with increasing leaf age, the decline being greater for plants grown in elevated C02 such that rates became lower than in ambient CO2. The degree of CO2-induced photosynthetic down-regulation as determined by A/C1 analysis was found to be dependent on leaf age. The major contribution to the decline in photosynthesis was likely to be a reduction in Rubisco activity as changes in stomataland mesophyll limitations were small. Instantaneous water use efficiency (WUE1) was greater for plants in elevated CO2, but these values declined rapidly with leaf age, whereas in ambient CO2 values were always lower, but were maintained for longer. Growth analysis indicated an increased root:-shoot ratio for plants grown in elevated CO2, this occurring almost entirely as a result of increased root growth. Greater root proliferation and increased WUE1, are characteristics which should give this persistent and troublesome weed an increased competitive advantage under projected conditions of climate change
AB - Rumex obtusifolius plants were grown for several months in daylit environment chambers (Solardomes) force-ventilated with air containing 350 or 600 µ;mol mol–1 C02. Elevated CO2 was found to accelerate the natural ontogenic decline in photosynthesis, but did not reduce leaf duration. In both CO2 treatments photosynthetic rates declined progressively with increasing leaf age, the decline being greater for plants grown in elevated C02 such that rates became lower than in ambient CO2. The degree of CO2-induced photosynthetic down-regulation as determined by A/C1 analysis was found to be dependent on leaf age. The major contribution to the decline in photosynthesis was likely to be a reduction in Rubisco activity as changes in stomataland mesophyll limitations were small. Instantaneous water use efficiency (WUE1) was greater for plants in elevated CO2, but these values declined rapidly with leaf age, whereas in ambient CO2 values were always lower, but were maintained for longer. Growth analysis indicated an increased root:-shoot ratio for plants grown in elevated CO2, this occurring almost entirely as a result of increased root growth. Greater root proliferation and increased WUE1, are characteristics which should give this persistent and troublesome weed an increased competitive advantage under projected conditions of climate change
KW - tusifoliu
KW - elevated CO2
KW - gas exchange
KW - leaf age
KW - senescence
U2 - 10.1093/jxb/46.11.1651
DO - 10.1093/jxb/46.11.1651
M3 - Journal article
VL - 46
SP - 1651
EP - 1659
JO - Journal of Experimental Botany
JF - Journal of Experimental Botany
SN - 1460-2431
IS - 11
ER -