BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Plasticity of crassulacean acid metabolism at subtropical latitudes: a pineapple case study

Participants in the publication
Nuno Rainha (Author)
Violante P. Medeiros (Author)
Mariana Câmara (Author)
Hélder Faustino (Author)
João P. Leite (Author)
Maria do Carmo Barreto (Author)
Cristina Cruz (Author)
Dep. Biologia Vegetal
cE3c
Carlos A. Pacheco (Author)
Duarte Ponte (Author)
Anabela Bernardes da Silva (Author)
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Dep. Biologia Vegetal
BioISI

Summary
Plants with the crassulacean acid metabolism (CAM) express high-metabolic plasticity, to adjust to environmental stresses. This article hypothesizes that irradiance and nocturnal temperatures are the major limitations for CAM at higher latitudes such as the Azores (37?45’N). Circadian CAM expression in Ananas comosus L. Merr. (pineapple) was assessed by the diurnal pat- tern of leaf carbon fixation into L-malate at the solstices and equinoxes, and confirmed by determining maximal phosphoenolpyruvate carboxylase (PEPC) activity in plant material. Metabolic adjustments to environmental conditions were confirmed by gas exchange measurements, and integrated with envi- ronmental data to determine CAM’s limiting factors: light and temperature. CAM plasticity was observed at the equinoxes, under similar photoperiods, but different environmental conditions. In spring, CAM expression was sim- ilar between vegetative and flowering plants, while in autumn, flowering (before anthesis) and fructifying (with fully developed fruit before ripening) plants accumulated more L-malate. Below 100μmolm−2 s−1, CAM phase I was extended, reducing CAM phase III during the day. Carbon fixation inhi- bition may occur by two major pathways: nocturnal temperature (<15?C) inhibiting PEPC activity and L-malate accumulation; and low irradiance influ- encing the interplay between CAM phase I and III, affecting carboxylation and decarboxylation. Both have important consequences for plant develop- ment in autumn and winter. Observations were confirmed by flowering time prediction using environmental data, emphasizing that CAM expression had a strong seasonal regulation due to a complex network response to light and temperature, allowing pineapple to survive in environments not suitable for high productivity.


Where published
Physiologia Plantarum

Publication Identifiers
ISSN - 0031-9317

Publisher
Wiley



Document Identifiers
URL - http://dx.doi.org/10.1111/ppl.12386
DOI - https://doi.org/10.1111/ppl.12386

Rankings
SCIMAGO Q1 (2016) - 1.511 - Plant Science
SCIMAGO Q1 (2016) - 1.511 - Physiology

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