The role of transient starch in acclimation to elevated atmospheric CO2

FEBS Letters

Frommer, Wolf B⁵  Geiger, Michael²  Gillissen, Bernd⁵  Heineke, Dieter⁴  Ludewig, Frank³  Kauder, Friedrich⁴  Müller-Röber, Bernd T¹  Sonnewald, Uwe³  Kühn, Christina⁵  Stitt, Mark² 

[1] Max-Planck-Institut für molekulare Pflanzenphysiologie, Karl-Liebknecht-Str. 25, 14476 Golm, Germany;Botanical Institute, University Heidelberg, Im Neuenheimer Feld 360, D-61920 Heidelberg, Germany;Institut für Pflanzengenetik und Kulturpflanzenforschung, Corrensstraße 3, 06466 Gatersleben, Germany;Institut für Biochemie der Pflanze, Untere Karspüle 2, 37073 Göttingen, Germany;Botanical Institute, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, Germany

关键词: Carbon dioxide;    Photosynthesis;    ADP-glucose pyrophosphorylase;    Antisense;    Sugar sensing;    Solanum tuberosum;   

DOI  :  10.1016/S0014-5793(98)00580-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Although increased concentrations of CO₂ stimulate photosynthesis, this stimulation is often lost during prolonged exposure to elevated carbon dioxide, leading to an attenuation of the potential gain in yield. Under these conditions, a wide variety of species accumulates non-structural carbohydrates in leaves. It has been proposed that starch accumulation directly inhibits photosynthesis, that the rate of sucrose and starch synthesis limits photosynthesis, or that accumulation of sugars triggers changes in gene expression resulting in lower activities of Rubisco and inhibition of photosynthesis. To distinguish these explanations, transgenic plants unable to accumulate transient starch due to leaf mesophyll-specific antisense expression of AGP B were grown at ambient and elevated carbon dioxide. There was a positive correlation between the capacity for starch synthesis and the rate of photosynthesis at elevated CO₂ concentrations, showing that the capability to synthesize leaf starch is essential for photosynthesis in elevated carbon dioxide. The results show that in elevated carbon dioxide, photosynthesis is restricted by the rate of end product synthesis. Accumulation of starch is not responsible for inhibition of photosynthesis. Although transgenic plants contained increased levels of hexoses, transcripts of photosynthetic genes were not downregulated and Rubisco activity was not decreased arguing against a role of sugar sensing in acclimation to high CO₂.

【 授权许可】

Unknown