Impact of high atmospheric CO2 concentrations on the seasonality of water-related processes, gas exchange, and carbohydrate metabolism in coffee trees under field conditions

Autor(es)

Esteves Sanches, Rodrigo Fazani ^[1] ; Centeno, Danilo da Cruz ^[2] ; Braga, Marcia Regina ^[1] ; da Silva, Emerson Alves ^[1]

Afiliação do(s) autor(es)

^[1] Inst Bot, Nucleo Pesquisa Fisiol & Bioquim, BR-04045972 Sao Paulo, SP - Brazil

^[2] Univ Fed ABC, Ctr Ciencias Nat & Humans, BR-09606070 Sao Bernardo Do Campo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Climatic Change; v. 162, n. 3 JUN 2020.
• Citações Web of Science: 0

Resumo

Increasing atmospheric CO2 concentrations ({[}CO2]) are unequivocal, widespread, and responsible for increased mean global temperatures and altered precipitation patterns. In this context, among the topics that need to be better understood are the changes in the water-related processes and gas exchange properties of plants grown under these conditions. Notably, the effects of climate change on coffee (Coffea spp.) production are particularly concerning given the importance of this commodity. Especially, it has been reported that coffee trees exhibit better photosynthetic efficiency when grown at higher {[}CO2] levels. In order to elucidate the mechanisms involved with this response, the seasonality of water-related processes, gas exchange, and carbohydrate metabolism were investigated using C. arabica var. Red Catuai grown at ambient and high {[}CO2] under field conditions, at a free-air CO2 enrichment (FACE) facility for coffee, in Brazil. The trees were evaluated fortnightly, from November to February (hot and rainy-summer) and from June to September (cold and dry-winter). It was found that C. arabica trees grown under high {[}CO2] conditions exhibited increased photosynthetic rates (averaging 121% higher in summer and 45% higher in winter) in both seasons, without displaying any significant changes in the seasonal photosynthesis pattern. Additionally, there was a tendency for the coffee trees grown at high {[}CO2] to exhibit increased levels of soluble carbohydrates, organic acids, and amino acids in the leaves. Our findings suggest that coffee trees adapt to increased {[}CO2] through increased photosynthetic rates, enhanced stomatal conductance regulation, and augmented carbohydrate and organic acid synthesis. It is plausible that these features could help mitigate the effects caused by climate change. (AU)

• Processo FAPESP: 12/08875-3 - Efeitos da alta concentração atmosférica de CO2 em câmaras de topo aberto e sistema face sobre a fotossíntese e os mecanismos naturais de resistência do cafeeiro à ferrugem
• Beneficiário: Emerson Alves da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular