Fluorescent probes offer sharper view of plant tissues

Researchers from the Indian Institute of Technology Gandhinagar (IITGN) and the Regional Centre for Biotechnology, Faridabad, have created novel fluorescent probes that enhance the visualization of xylem – the specialized tissue responsible for transporting water and minerals within plant structures. Published in Plant and Cell Physiology, the study introduces a superior staining method that outperforms conventional dyes, facilitating advancements in plant development, vascular biology, and crop resilience research.

Xylem, along with phloem, serves as the two essential pipe networks in vascular plants, with xylem transporting water and dissolved minerals upward from roots. The conventional dye staining process, involving plant tissue slicing and staining with dyes like propidium iodide or rhodamine, often results in mixed signals from various tissues, making it challenging to distinguish xylem from phloem and cambium.

The newly developed probes, built with donor–π–acceptor architecture, selectively bind to xylem tissue, providing sharper and more specific images with lower concentrations and reduced laser power. This lowers photobleaching and background staining, improving image quality while reducing unnecessary dye usage. The probes were tested on Arabidopsis thaliana, Nicotiana benthamiana, and Allium fistulosum, demonstrating their effectiveness across different plant species.

Additionally, the probes revealed structural abnormalities in Arabidopsis eskimo1 mutant plants with collapsed xylem vessels. Overall, these probes aim to improve experimental tools for plant scientists, enabling clearer investigations into plant development, vascular defects, and environmental responses. However, further research is required to understand the binding mechanism of the dyes on cell walls and to adapt them for use in living tissues.