2024-03-29T09:29:57Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/189492022-06-01T13:10:08Zcom_10261_53com_10261_6col_10261_306
Acclimation to future atmospheric CO2 levels increases photochemical efficiency and mitigates photochemistry inhibition by warm temperatures in wheat under field chambers.
Gutiérrez del Pozo, Diego
Gutiérrez Rodríguez, Elena
Pérez Pérez, Pilar
Morcuende, Rosa
Verdejo, Ángel L.
Martínez-Carrasco, Rafael
Acclimation
chlorophyll a:b ratio;
Chlorophyll fluorescence
Carbon assimilation
elevated CO2
elevated temperature
Crop yield
wheat
A study was conducted over two years to determine whether growth under elevated CO2
(700 μmol mol-1) and temperature (ambient + 4ºC) conditions modifies photochemical
efficiency or only the use of electron transport products in spring wheat grown in field
chambers. Elevated atmospheric CO2 concentrations increased crop dry matter at
maturity by 12%-17%, while above-ambient temperatures did not significantly affect
dry matter yield. In measurements with ambient CO2 at ear emergence and after
anthesis, growth at elevated CO2 concentrations decreased flag leaf light-saturated
carbon assimilation. The quantum yield of electron transport (ΦPSII) measured at
ambient CO2 and higher irradiances increased at ear emergence and decreased after
anthesis in plants grown at elevated CO2. At higher light intensities, but not in low light,
photochemical quenching (qP) decreased after growth in elevated CO2 conditions.
Growth under CO2 enrichment increased dark- (Fv:Fm) and light-adapted (Fv’:Fm’)
photochemical efficiencies, and decreased the chlorophyll a:b ratio, suggesting an
increase in light-harvesting complexes relative to PSII reaction centres. A relatively
higher decrease in carbon assimilation than the decrease in ΦPSII pointed to a sink other
than CO2 assimilation for electron-transport products at defined growth stages. With
higher light intensities, warmer temperatures increased ΦPSII and Fv’:Fm’ at ear
emergence and decreased ΦPSII after anthesis; in ambient -but not elevated- CO2,
warmer temperatures also decreased qP after anthesis. CO2 fixation increased or did not
change with temperature, depending on the growth stage and year.
We conclude that elevated CO2 decreases the carbon assimilation capacity, but
increases photochemistry and resource allocation to light harvesting, and that elevated
levels of CO2 can mitigate photochemistry inhibition due to warm temperatures.
2009
artículo
Physiologia Plantarum 137,.86-100. (2009)
10261/18949
10.1111/j.1399-3054.2009.01256.x
eng
http://www.wiley.com/bw/journal.asp?ref=0031-9317&site=1
openAccess
Wiley-Blackwell