Speaker
Description
The spore and pollen wall is among the most chemically complex and resilient biological materials, yet its composition and assembly remain poorly understood. Although genetic studies have identified many enzymes and transport pathways required for pollen wall development, the chemistry of sporopollenin remains debated, and the developmental processes linking biosynthesis, transport, and polymer assembly have remained largely inaccessible. Here, we present a multimodal synchrotron imaging framework to investigate pollen wall development within Arabidopsis thaliana anthers. Using cryosectioned anthers spanning key stages of pollen wall formation, we combined synchrotron mid-infrared (S-IR) spectromicroscopy with optical photothermal infrared (O-PTIR) spectroscopy to characterize chemical changes within the native anther environment. Principal component analysis of S-IR spectra resolved stage-specific chemical signatures that revealed progressive changes in molecular composition during sporopollenin deposition. Complementary O-PTIR measurements provided higher spatial resolution, enabling localized chemical features associated with the developing pollen wall to be examined. These approaches capture chemical transitions that are inaccessible using conventional analyses of isolated mature pollen. Beyond revealing the chemistry of pollen wall formation, this work establishes a multimodal imaging framework for studying complex metabolic and developmental processes in plants within their native spatial context. Building on this framework, ongoing integration of synchrotron X-ray fluorescence microscopy will provide complementary elemental information at cellular and tissue scales, creating opportunities to relate molecular and elemental dynamics during pollen wall development. These complementary approaches establish a foundation for linking genetic models of sporopollenin biosynthesis with their chemical outputs in situ and illustrate the broader potential of emerging multimodal synchrotron imaging platforms such as XLEAP to investigate complex developmental processes in plants.