Nocturnal sucrose does not reflect the hydrogen isotope composition of transitory starch in leaves as expected DOI
Alexander Wacker, Daniel B. Nelson, Guillaume Tcherkez

et al.

Plant Biology, Journal Year: 2025, Volume and Issue: unknown

Published: April 28, 2025

Abstract The hydrogen isotope composition ( δ 2 H) of cellulose is inherently linked to that sucrose synthesized in leaves. Daytime from triose phosphates produced by the Calvin‐Benson‐Bassham cycle, while nighttime remobilized transitory starch Photosynthetic metabolism causes be naturally H‐depleted relative phosphates. Thus, H values should vary diurnally. However, this has not been tested. We made diel measurements and three species differing their sucrose/starch dynamics (bean, radish sunflower) under climate controlled steady‐state isotopic conditions. Leaf was degraded at night around 90‰ compared with daytime sucrose. all tested we surprisingly observed no effect on and, instead, only species‐specific differences. Consequently, apparent fractionation associated biosynthesis (ε ) indistinguishable between day within −140‰ −180‰ across species. lack day/night variation ε could originate cytosolic sugar H‐enrichment H‐atom positions counteracting H‐depletion starch. Using a simplified model metabolism, show differences fluxes can reduce expected . From practical perspective, suggests that: (i) estimating single time point might sufficient capture conditions; (ii) extract more than one metabolically sensitive signals given compound, position‐specific analysis will required.

Language: Английский

Nocturnal sucrose does not reflect the hydrogen isotope composition of transitory starch in leaves as expected DOI
Alexander Wacker, Daniel B. Nelson, Guillaume Tcherkez

et al.

Plant Biology, Journal Year: 2025, Volume and Issue: unknown

Published: April 28, 2025

Abstract The hydrogen isotope composition ( δ 2 H) of cellulose is inherently linked to that sucrose synthesized in leaves. Daytime from triose phosphates produced by the Calvin‐Benson‐Bassham cycle, while nighttime remobilized transitory starch Photosynthetic metabolism causes be naturally H‐depleted relative phosphates. Thus, H values should vary diurnally. However, this has not been tested. We made diel measurements and three species differing their sucrose/starch dynamics (bean, radish sunflower) under climate controlled steady‐state isotopic conditions. Leaf was degraded at night around 90‰ compared with daytime sucrose. all tested we surprisingly observed no effect on and, instead, only species‐specific differences. Consequently, apparent fractionation associated biosynthesis (ε ) indistinguishable between day within −140‰ −180‰ across species. lack day/night variation ε could originate cytosolic sugar H‐enrichment H‐atom positions counteracting H‐depletion starch. Using a simplified model metabolism, show differences fluxes can reduce expected . From practical perspective, suggests that: (i) estimating single time point might sufficient capture conditions; (ii) extract more than one metabolically sensitive signals given compound, position‐specific analysis will required.

Language: Английский

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