Fast and simple fluorometric measurement of phloem loading exposes auxin-dependent regulation of Arabidopsis sucrose transporter AtSUC2.

ABSTRACT: The rate of sucrose export from leaves is a major factor in balancing whole-plant carbon and energy partitioning. A comprehensive study of its dynamics and relationship to photosynthesis, sink demand, and other relevant processes is hampered by the shortcomings of current methods for measuring sucrose phloem loading. We utilize the ability of sucrose transporter proteins, known as SUCs or SUTs, to specifically transport the fluorescent molecule esculin in a novel assay to measure phloem loading rates. Esculin was administered to source leaves and its fluorescence in the leaf extract was measured after 1 or 2 h. Dicot plants with an active phloem loading strategy showed an export-dependent reduction of esculin fluorescence. Relative leaf esculin export rates correlated with leaf export rate

SUBMITTER: Ren Y 

PROVIDER: S-EPMC11629736 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature