%0 Journal Article %1 Bernacchi2005Growth %A Bernacchi, CarlJ %A Morgan, PatrickB %A Ort, DonaldR %A Long, StephenP %B Planta %D 2005 %I Springer-Verlag %K euporias %N 3 %P 434--446 %R 10.1007/s00425-004-1320-8 %T The growth of soybean under free air CO2 enrichment (FACE) stimulates photosynthesis while decreasing in vivo Rubisco capacity %U http://dx.doi.org/10.1007/s00425-004-1320-8 %V 220 %X Down-regulation of light-saturated photosynthesis (A sat) at elevated atmospheric CO2 concentration, CO2, has been demonstrated for many C3 species and is often associated with inability to utilize additional photosynthate and/or nitrogen limitation. In soybean, a nitrogen-fixing species, both limitations are less likely than in crops lacking an N-fixing symbiont. Prior studies have used controlled environment or field enclosures where the artificial environment can modify responses to CO2. A soybean free air CO2 enrichment (FACE) facility has provided the first opportunity to analyze the effects of elevated CO2 on photosynthesis under fully open-air conditions. Potential ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (V c,max) and electron transport through photosystem II (J max) were determined from the responses of A sat to intercellular CO2 (C i) throughout two growing seasons. Mesophyll conductance to CO2 (g m) was determined from the responses of A sat and whole chain electron transport (J) to light. Elevated CO2 increased A sat by 15–20\% even though there was a small, statistically significant, decrease in V c,max. This differs from previous studies in that V c,max/J max decreased, inferring a shift in resource investment away from Rubisco. This raised the C i at which the transition from Rubisco-limited to ribulose-1,5-bisphosphate regeneration-limited photosynthesis occurred. The decrease in V c,max was not the result of a change in g m, which was unchanged by elevated CO2. This first analysis of limitations to soybean photosynthesis under fully open-air conditions reveals important differences to prior studies that have used enclosures to elevate CO2, most significantly a smaller response of A sat and an apparent shift in resources away from Rubisco relative to capacity for electron transport.

@article{Bernacchi2005Growth, abstract = {Down-regulation of light-saturated photosynthesis (A sat) at elevated atmospheric {CO2} concentration, [{CO2}], has been demonstrated for many C3 species and is often associated with inability to utilize additional photosynthate and/or nitrogen limitation. In soybean, a nitrogen-fixing species, both limitations are less likely than in crops lacking an N-fixing symbiont. Prior studies have used controlled environment or field enclosures where the artificial environment can modify responses to [{CO2}]. A soybean free air [{CO2}] enrichment ({FACE}) facility has provided the first opportunity to analyze the effects of elevated [{CO2}] on photosynthesis under fully open-air conditions. Potential ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (V c,max) and electron transport through photosystem {II} (J max) were determined from the responses of A sat to intercellular [{CO2}] (C i) throughout two growing seasons. Mesophyll conductance to {CO2} (g m) was determined from the responses of A sat and whole chain electron transport (J) to light. Elevated [{CO2}] increased A sat by 15–20\% even though there was a small, statistically significant, decrease in V c,max. This differs from previous studies in that V {c,max/J} max decreased, inferring a shift in resource investment away from Rubisco. This raised the C i at which the transition from Rubisco-limited to ribulose-1,5-bisphosphate regeneration-limited photosynthesis occurred. The decrease in V c,max was not the result of a change in g m, which was unchanged by elevated [{CO2}]. This first analysis of limitations to soybean photosynthesis under fully open-air conditions reveals important differences to prior studies that have used enclosures to elevate [{CO2}], most significantly a smaller response of A sat and an apparent shift in resources away from Rubisco relative to capacity for electron transport.}, added-at = {2019-08-14T18:35:35.000+0200}, author = {Bernacchi, CarlJ and Morgan, PatrickB and Ort, DonaldR and Long, StephenP}, biburl = {https://www.bibsonomy.org/bibtex/26ef8563c1ae7aa46e0aa53f624bcabf9/karinawilliams}, booktitle = {Planta}, citeulike-article-id = {12889538}, citeulike-linkout-0 = {http://dx.doi.org/10.1007/s00425-004-1320-8}, citeulike-linkout-1 = {http://link.springer.com/article/10.1007/s00425-004-1320-8}, doi = {10.1007/s00425-004-1320-8}, interhash = {abcfcefb86f174b2dc3828ce1cc21016}, intrahash = {6ef8563c1ae7aa46e0aa53f624bcabf9}, keywords = {euporias}, number = 3, pages = {434--446}, posted-at = {2016-08-26 15:24:05}, priority = {2}, publisher = {Springer-Verlag}, timestamp = {2019-08-14T18:35:35.000+0200}, title = {The growth of soybean under free air [{CO2}] enrichment ({FACE}) stimulates photosynthesis while decreasing in vivo Rubisco capacity}, url = {http://dx.doi.org/10.1007/s00425-004-1320-8}, volume = 220, year = 2005 }