title: Long-term elevated air [CO2 ] strengthens photosynthetic functioning and mitigates the impact of supra-optimal temperatures in tropical Coffea arabica and C. canephora species.
abstract: The tropical coffee crop has been predicted to be threatened by future climate changes and global warming. However, the real biological effects of such changes remain unknown. Therefore, this work aims to link the physiological and biochemical responses of photosynthesis to elevated air [CO2 ] and temperature in cultivated genotypes of Coffea arabica L. (cv. Icatu and IPR108) and Coffea canephora cv. Conilon CL153. Plants were grown for ca. 10 months at 25/20°C (day/night) and 380 or 700 μl CO2 l(-1) and then subjected to temperature increase (0.5°C day(-1) ) to 42/34°C. Leaf impacts related to stomatal traits, gas exchanges, C isotope composition, fluorescence parameters, thylakoid electron transport and enzyme activities were assessed at 25/20, 31/25, 37/30 and 42/34°C. The results showed that (1) both species were remarkably heat tolerant up to 37/30°C, but at 42/34°C a threshold for irreversible nonstomatal deleterious effects was reached. Impairments were greater in C. arabica (especially in Icatu) and under normal [CO2 ]. Photosystems and thylakoid electron transport were shown to be quite heat tolerant, contrasting to the enzymes related to energy metabolism, including RuBisCO, which were the most sensitive components. (2) Significant stomatal trait modifications were promoted almost exclusively by temperature and were species dependent. Elevated [CO2 ], (3) strongly mitigated the impact of temperature on both species, particularly at 42/34°C, modifying the response to supra-optimal temperatures, (4) promoted higher water-use efficiency under moderately higher temperature (31/25°C) and (5) did not provoke photosynthetic downregulation. Instead, enhancements in [CO2 ] strengthened photosynthetic photochemical efficiency, energy use and biochemical functioning at all temperatures. Our novel findings demonstrate a relevant heat resilience of coffee species and that elevated [CO2 ] remarkably mitigated the impact of heat on coffee physiology, therefore playing a key role in this crop sustainability under future climate change scenarios.
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.|Setor Fisiologia Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Univ. Estadual Norte Fluminense (UENF), Darcy Ribeiro, RJ, Brazil.
authors.forename: Weverton P
authors.initials: WP
authors.lastname: Rodrigues
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.|Centro Univ. Norte do Espírito Santo (CEUNES), Dept. Ciências Agrárias e Biológicas (DCAB), Univ. Federal Espírito Santo (UFES), Rod. BR 101 Norte, Km. 60, Bairro Litorâneo, CEP: 29932-540, São Mateus, ES, Brazil.
authors.forename: Madlles Q
authors.initials: MQ
authors.lastname: Martins
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.|Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity) and Centro de Estudos Florestais, Instituto Superior Agronomia, Univ. Lisboa, Tapada da Ajuda, Lisboa, 1349-017, Portugal.
authors.forename: Ana S
authors.initials: AS
authors.lastname: Fortunato
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity) and Centro de Estudos Florestais, Instituto Superior Agronomia, Univ. Lisboa, Tapada da Ajuda, Lisboa, 1349-017, Portugal.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Rodrigues
authors.affiliation: Unid. Investigação em Biotecnologia e Recursos Genéticos, Instituto Nacional de Investigação Agrária e Veterinária, I.P. (INIAV), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.
authors.forename: José N
authors.initials: JN
authors.lastname: Semedo
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.|Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity) and Centro de Estudos Florestais, Instituto Superior Agronomia, Univ. Lisboa, Tapada da Ajuda, Lisboa, 1349-017, Portugal.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Simões-Costa
authors.affiliation: Unid. Investigação em Biotecnologia e Recursos Genéticos, Instituto Nacional de Investigação Agrária e Veterinária, I.P. (INIAV), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.
authors.forename: Isabel P
authors.initials: IP
authors.lastname: Pais
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.|Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity) and Centro de Estudos Florestais, Instituto Superior Agronomia, Univ. Lisboa, Tapada da Ajuda, Lisboa, 1349-017, Portugal.|GeoBioTec, Fac. Ciências Tecnologia, Univ. Nova Lisboa, Caparica, 2829-516, Portugal.
authors.forename: António E
authors.initials: AE
authors.lastname: Leitão
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.|Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity) and Centro de Estudos Florestais, Instituto Superior Agronomia, Univ. Lisboa, Tapada da Ajuda, Lisboa, 1349-017, Portugal.
authors.forename: Filipe
authors.initials: F
authors.lastname: Colwell
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.
authors.forename: Luis
authors.initials: L
authors.lastname: Goulao
authors.affiliation: Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculty Sciences, Univ. Lisbon, Campo Grande, Lisboa, 1749-016, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Máguas
authors.affiliation: Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculty Sciences, Univ. Lisbon, Campo Grande, Lisboa, 1749-016, Portugal.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Maia
authors.affiliation: Centro Univ. Norte do Espírito Santo (CEUNES), Dept. Ciências Agrárias e Biológicas (DCAB), Univ. Federal Espírito Santo (UFES), Rod. BR 101 Norte, Km. 60, Bairro Litorâneo, CEP: 29932-540, São Mateus, ES, Brazil.
authors.forename: Fábio L
authors.initials: FL
authors.lastname: Partelli
authors.affiliation: Setor Fisiologia Vegetal, Centro de Ciências e Tecnologias Agropecuárias, Univ. Estadual Norte Fluminense (UENF), Darcy Ribeiro, RJ, Brazil.
authors.forename: Eliemar
authors.initials: E
authors.lastname: Campostrini
authors.affiliation: Unid. Investigação em Biotecnologia e Recursos Genéticos, Instituto Nacional de Investigação Agrária e Veterinária, I.P. (INIAV), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.
authors.forename: Paula
authors.initials: P
authors.lastname: Scotti-Campos
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.|Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity) and Centro de Estudos Florestais, Instituto Superior Agronomia, Univ. Lisboa, Tapada da Ajuda, Lisboa, 1349-017, Portugal.|GeoBioTec, Fac. Ciências Tecnologia, Univ. Nova Lisboa, Caparica, 2829-516, Portugal.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Ribeiro-Barros
authors.affiliation: GeoBioTec, Fac. Ciências Tecnologia, Univ. Nova Lisboa, Caparica, 2829-516, Portugal.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Lidon
authors.affiliation: Dept. Biologia Vegetal, Univ. Federal Viçosa (UFV), Viçosa, 36570-000, MG, Brazil.
authors.forename: Fábio M
authors.initials: FM
authors.lastname: DaMatta
authors.affiliation: Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity), Instituto Investigação Científica Tropical, I.P. (IICT), Qta. Marquês, Av. República, Oeiras, 2784-505, Portugal.|Grupo Interações Planta-Ambiente & Biodiversidade (PlantStress&Biodiversity) and Centro de Estudos Florestais, Instituto Superior Agronomia, Univ. Lisboa, Tapada da Ajuda, Lisboa, 1349-017, Portugal.|GeoBioTec, Fac. Ciências Tecnologia, Univ. Nova Lisboa, Caparica, 2829-516, Portugal.
authors.forename: José C
authors.identifier: http://orcid.org/0000-0002-7639-7214
authors.initials: JC
authors.lastname: Ramalho
mesh_terms: D000064:Acclimatization; D002245:Carbon Dioxide / Q000378:metabolism*; D057231:Climate Change; D040503:Coffea / Q000502:physiology*; D004579:Electron Transport; D005838:Genotype; D057232:Global Warming; D006358:Hot Temperature; D010788:Photosynthesis / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology; D054046:Plant Stomata / Q000502:physiology; D020524:Thylakoids / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water; D002245:Carbon Dioxide
keywords: RuBisCO; chloroplast; coffee; elevated [CO2]; global warming; heat; photosynthesis; photosystems; respiratory enzymes; stomatal traits; water-use efficiency