02759naa a2200397 a 450000100080000000500110000800800410001910000190006024502160007926000090029552015520030465000180185665000190187465000190189365000090191265000130192165000190193465000110195365000100196465000100197465000240198465000180200865000240202665300210205065300310207165300310210265300120213370000170214570000250216270000220218770000260220970000180223570000190225370000140227277300750228620347442017-03-02       2016    bl ---       0--  u    #d1 aDaMATTA, F. M.  aSustained enhancement of photosynthesis in coffee trees grown under free-air CO2 enrichment conditionsbdisentangling the contributions of stomatal, mesophyll, and biochemical limitations.h[electronic resource]  c2016  aAbstract: Coffee (Coffea spp.), a globally traded commodity, is a slow-growing tropical tree species that displays an improved photosynthetic performance when grown under elevated atmospheric CO2 concentrations ([CO2]). To investigate the mechanisms underlying this response, two commercial coffee cultivars (Catuaí and Obatã) were grown using the first free-air CO2 enrichment (FACE) facility in Latin America. Measurements were conducted in two contrasting growth seasons, which were characterized by the high (February) and low (August) sink demand. Elevated [CO2] led to increases in net photosynthetic rates (A) in parallel with decreased photorespiration rates, with no photochemical limitations to A. The stimulation of A by elevated CO2 supply was more prominent in August (56% on average) than in February (40% on average). Overall, the stomatal and mesophyll conductances, as well as the leaf nitrogen and phosphorus concentrations, were unresponsive to the treatments. Photosynthesis was strongly limited by diffusional constraints, particularly at the stomata level, and this pattern was little, if at all, affected by elevated [CO2]. Relative to February, starch pools (but not soluble sugars) increased remarkably (&gt500%) in August, with no detectable alteration in the maximum carboxylation capacity estimated on a chloroplast [CO2] basis. Upregulation of A by elevated [CO2] took place with no signs of photosynthetic downregulation, even during the period of low sink demand, when acclimation would be expected to be greatest.  acarbohydrates  aCarbon dioxide  aClimate change  aface  anitrogen  aPhotosynthesis  astarch  aCafé  aClima  aDióxido de carbono  aFotossíntese  aMudança Climática  aCoffea arabica L  aPhotosynthetic acclimation  aPhotosynthetic limitations  aStartch1 aGODOY, A. G.1 aMENEZES-SILVA, P. E.1 aMARTINS, S. C. V.1 aSANGLARD, L. M. V. P.1 aMORAIS, L. E.1 aTORRE NETO, A.1 aGHINI, R.  tJournal of Experimental Botany, Londongv. 67, n. 1, p. 341-352, 2016.