Infrared Microimaging of Sucrose Distribution in Plant Vascular Tissues

Sucrose is the primary transport sugar in plants, serving as an essential energy source and signaling molecule. Detection, visualization, and quantification of sucrose in various plant tissues are essential for understanding the metabolic and physiological processes that sustain plant life. Traditional metabolite-mapping techniques have struggled to visualize the quantitative distribution of sucrose at sufficient resolution to distinguish vascular bundles from surrounding tissues. Here, we present a Fourier-transform infrared (FTIR) imaging approach that can visualize sucrose in plant tissues quantitatively at a microscopic resolution (~12 µm). This IR-based, label-free method can be used with both model plants and agriculturally important crops. The assay has a detection range of 20-1000 mM and can map sucrose distribution within complex organs such as stems, leaves, and seeds. Notably, it enables the precise quantification of sucrose levels in vascular tissues. This is a trait of great interest in many current breeding and plant biotechnology approaches aimed at increasing crop yield.