Advances in <i>In Situ</i> Probing of Plant Cell Wall Polysaccharides

The plant cell wall forms the structural framework and load-bearing component, which is crucial for the growth and differentiation of plant tissues. It is composed of dynamic, interconnected networks of polysaccharides, glycoproteins, and lignin. Polysaccharides play a critical role in regulating cell wall assembly, mechanics, and growth. Accurate and rapid visualization of polysaccharide distribution within plant cell walls is increasingly important for refining structural models and advancing bioenergy industrialization. This review highlights widely applied techniques for <i>in situ</i> characterization of cell wall polysaccharides at the tissue or single-cell level, including immunofluorescence labeling, Raman imaging, infrared spectroscopic imaging, atomic force microscopy, mass spectrometry imaging, and solid-state nuclear magnetic resonance, accompanied by examples to illustrate their practical utility. Special emphasis is placed on the underlying principles and applications in elucidating the architecture and biological functionality of polysaccharides within plant cell walls, thereby underscoring their relevance in advancing both fundamental and applied plant science research.