Acclimation to future atmospheric CO levels increases photochemical efficiency and mitigates photochemistry inhibition by warm temperatures in wheat under field chambers

A study was conducted over 2 years to determine whether growth under elevated CO(2) (700 mumol mol(-1)) and temperature (ambient + 4 degrees C) conditions modifies photochemical efficiency or only the use of electron transport products in spring wheat grown in field chambers. Elevated atmospheric CO(2) 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 CO(2) at ear emergence and after anthesis, growth at elevated CO(2) concentrations decreased flag leaf light-saturated carbon assimilation. The quantum yield of electron transport (Phi(PSII)) measured at ambient CO(2) and higher irradiances increased...

Categories: Publication; Types: Citation, Journal Citation; Tags: Physiologia Plantarum

Diffusion limitations and metabolic factors associated with inhibition and recovery of photosynthesis from drought stress in a C perennial grass species.

Stomatal closure and metabolic impairment under drought stress limits photosynthesis. The objective of this study was to determine major stomatal and metabolic factors involved in photosynthetic responses to drought and recovery upon re-watering in a C(3) perennial grass species, Kentucky bluegrass (Poa pratensis L.). Two genotypes differing in drought resistance, 'Midnight' (tolerant) and 'Brilliant' (sensitive), were subjected to drought stress for 15 days and then re-watered for 10 days in growth chambers. Single-leaf net photosynthetic rate (A), stomatal conductance (g(s)) and transpiration rate (Tr) decreased during drought, with a less rapid decline in 'Midnight' than in 'Brilliant'. Photochemical efficiency,...

Categories: Publication; Types: Citation, Journal Citation; Tags: Physiologia Plantarum