| Autor: |
de Souza AH; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil., de Oliveira US; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil., Oliveira LA; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil., de Carvalho PHN; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil., de Andrade MT; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil., Pereira TS; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil., Gomes Junior CC; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil., Cardoso AA; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA., Ramalho JDC; PlantStress & Biodiversity Lab., Centro de Estudos Florestais (CEF), Laboratório Associado Terra, Departamento de Recursos Naturais, Ambiente e Território (DRAT), Instituto Superior de Agronomia (ISA), Universidade de Lisboa (ULisboa), Quinta do Marquês, Av. da República, 2784-505 Oeiras, Portugal.; Unidade de Geobiociências, Geoengenharias e Geotecnologias (GeoBioTec), Faculdade de Ciências e Tecnologia (FCT), Universidade NOVA de Lisboa (UNL), Monte de Caparica, 2829-516 Caparica, Portugal., Martins SCV; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil., DaMatta FM; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, MG, Brazil. |
| Abstrakt: |
Coffee ( Coffea arabica L.) plants have been assorted as highly suitable to growth at elevated [CO 2 ] (e C a ), although such suitability is hypothesized to decrease under severe shade. We herein examined how the combination of e C a and contrasting irradiance affects growth and photosynthetic performance. Coffee plants were grown in open-top chambers under relatively high light (HL) or low light (LL) (9 or 1 mol photons m -2 day -1 , respectively), and a C a or e C a (437 or 705 μmol mol -1 , respectively). Most traits were affected by light and CO 2 , and by their interaction. Relative to a C a , our main findings were (i) a greater stomatal conductance ( g s ) (only at HL) with decreased diffusive limitations to photosynthesis, (ii) greater g s during HL-to-LL transitions, whereas g s was unresponsive to the LL-to-HL transitions irrespective of [CO 2 ], (iii) greater leaf nitrogen pools (only at HL) and higher photosynthetic nitrogen-use efficiency irrespective of light, (iv) lack of photosynthetic acclimation, and (v) greater biomass partitioning to roots and earlier branching. In summary, e C a improved plant growth and photosynthetic performance. Our novel and timely findings suggest that coffee plants are highly suited for a changing climate characterized by a progressive elevation of [CO 2 ], especially if the light is nonlimiting. |
