Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for three years under fully open air conditions.

published or submitted for publicatio

Will photosynthesis of maize (Zea mays) in the US corn belt increase in future [CO2] rich atmospheres? An analysis of diurnal courses of [CO2] uptake under Free-Air Concentration Enrichmnent (FACE).

published or submitted for publicatio

Abiotic Stress‐Related Expressed Sequence Tags from the Diploid Strawberry Fragaria vesca

Strawberry ( spp.) is a eudicotyledonous plant that belongs to the Rosaceae family, which includes other agronomically important plants such as raspberry ( L.) and several tree-fruit species. Despite the vital role played by cultivated strawberry in agriculture, few stress-related gene expression characterizations of this crop are available. To increase the diversity of available transcriptome sequence, we produced 41,430 L. expressed sequence tags (ESTs) from plants growing under water-, temperature-, and osmotic-stress conditions as well as a combination of heat and osmotic stresses that is often found in irrigated fields. Clustering and assembling of the ESTs resulted in a total of 11,836 contigs and singletons that were annotated using Gene Ontology (GO) terms. Furthermore, over 1200 sequences with no match to available Rosaceae ESTs were found, including six that were assigned the “response to stress” GO category. Analysis of EST frequency provided an estimate of steady state transcript levels, with 91 sequences exhibiting at least a 20-fold difference between treatments. This EST collection represents a useful resource to advance our understanding of the abiotic stress-response mechanisms in strawberry. The sequence information may be translated to valuable tree crops in the Rosaceae family, where whole-plant treatments are not as simple or practical

FACE-ing the facts: inconsistencies and interdependence among field, chamber and modeling studies of elevated [CO2] impacts on crop yield and food supply.

published or submitted for publicatio

Long-term growth of soybean at elevated [CO2] does not cause acclimation of stomatal conductance under fully open-air conditions.

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Food for thought: Lower than expected crop yield stimulation with rising carbon dioxide concentrations.

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Arabidopsis transcript and metabolic profiles: ecotype-specific responses to open-air elevated [CO2].

published or submitted for publicationis peer reviewe

The quantum yield of flash-induced proton release by bacteriorhodopsin-containing membrane fragments

The quantum yield of proton release by bacteriorhodopsin was measured from volume changes after excitation of purple membrane fragments by short flashes. At low ionic strengths, about 0.25 mol of protons is released per einstein absorbed. This agrees well with quantum yields reported recently for the conversion of bacteriorhodopsin into a metastable state (M) that absorbs near 412 nm. However, the quantum yield of proton release increases gradually with increasing ionic strength; it plateaus with a value of 0.43 +/- 0.03 at ionic strengths above 200 mM. Changing the ionic strength has no detectable effect on the quantum yield of formation of the M spectral state. It thus appears that as many as two protons can be released and rebound in each photochemical cycle at high ionic strengths. The quantum yield of proton release is essentially independent of pH over the range 6.0–8.75. The quantum yield decreases with increasing flash strength, apparently due to photoreversal of the initial photochemical reaction