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Concurrent Measurement of O2 Production and Isoprene Emission During Photosynthesis: Pros, Cons and Metabolic Implications of Responses to Light, CO2 and Temperature.
Jardine, Kolby Jeremiah; Som, Suman; Gallo, Luiza Beraldi; Demus, Jilian; Domingues, Tomas Ferreira; Wistrom, Christina Marie; Gu, Lianhong; Tcherkez, Guillaume; Niinemets, Ülo.
Afiliação
  • Jardine KJ; Lawrence Berkeley National Laboratory, Climate and Ecosystem Sciences Division, Berkeley, California, USA.
  • Som S; Lawrence Berkeley National Laboratory, Climate and Ecosystem Sciences Division, Berkeley, California, USA.
  • Gallo LB; Lawrence Berkeley National Laboratory, Climate and Ecosystem Sciences Division, Berkeley, California, USA.
  • Demus J; FFCLRP, Departamento de Biologia, Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
  • Domingues TF; College of Natural Resources, University of California, Berkeley, Berkeley, California, USA.
  • Wistrom CM; FFCLRP, Departamento de Biologia, Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
  • Gu L; College of Natural Resources, University of California, Berkeley, Berkeley, California, USA.
  • Tcherkez G; Oak Ridge National Laboratory, Environmental Sciences Division and Climate Change Science Institute, Oak Ridge, Tennessee, USA.
  • Niinemets Ü; Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia.
Plant Cell Environ ; 2024 Sep 09.
Article em En | MEDLINE | ID: mdl-39248643
ABSTRACT
Traditional leaf gas exchange experiments have focused on net CO2 exchange (Anet). Here, using California poplar (Populus trichocarpa), we coupled measurements of net oxygen production (NOP), isoprene emissions and δ18O in O2 to traditional CO2/H2O gas exchange with chlorophyll fluorescence, and measured light, CO2 and temperature response curves. This allowed us to obtain a comprehensive picture of the photosynthetic redox budget including electron transport rate (ETR) and estimates of the mean assimilatory quotient (AQ = Anet/NOP). We found that Anet and NOP were linearly correlated across environmental gradients with similar observed AQ values during light (1.25 ± 0.05) and CO2 responses (1.23 ± 0.07). In contrast, AQ was suppressed during leaf temperature responses in the light (0.87 ± 0.28), potentially due to the acceleration of alternative ETR sinks like lipid synthesis. Anet and NOP had an optimum temperature (Topt) of 31°C, while ETR and δ18O in O2 (35°C) and isoprene emissions (39°C) had distinctly higher Topt. The results confirm a tight connection between water oxidation and ETR and support a view of light-dependent lipid synthesis primarily driven by photosynthetic ATP/NADPH not consumed by the Calvin-Benson cycle, as an important thermotolerance mechanism linked with high rates of (photo)respiration and CO2/O2 recycling.
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Texto completo: 1 Base de dados: MEDLINE Idioma: En Ano de publicação: 2024 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Idioma: En Ano de publicação: 2024 Tipo de documento: Article