New method helps researchers study proteins involved in plant health, disease

Plants, like humans, possess a diverse range of shapes and sizes. Scientists aim to understand the components of both plant and animal bodies to improve health and tackle diseases. Proteomics, the study of proteins inside cells, is a valuable tool in this pursuit, regardless of whether the proteins are found in humans, animals, plants, or viruses.

While significant advancements have been made in understanding human biology using proteomics, progress in plant proteomics has been slower due to the protective outer shell and thick cell wall surrounding plant tissues. This protective barrier also creates a scientific challenge. University of Delaware researchers have now developed a validated method to study proteins inside intact plant cells, breaking through this long-standing barrier in plant proteomics.

This breakthrough, detailed in an article published in Plant Physiology, opens new avenues for plant biology research, allowing scientists to answer previously difficult questions. Yanbao Yu, a proteomics director at UD's Department of Chemistry and Biochemistry, emphasized that the method could help identify biomarkers for plant infections, such as bacterial or fungal diseases, and may even lead to treatments for cell recovery.

The new technique involves treating intact plant tissue with methanol, which freezes the biology inside the cells, allowing researchers to study the proteins while preserving crucial information. This approach is more efficient than traditional methods, which require grinding up tissue and processing the extracted proteins, a time-consuming and potentially destructive procedure.

The UD-developed method has proven effective in various biological systems, including plants, worms, frogs, sea urchins, bacteria, neuroblastoma cells, and yeasts. Collaborating with Jeff Caplan and Deji Adekanye, Yu applied the new strategy to study healthy tobacco leaves and those infected with fungi, revealing distinct differences in the protein profiles of infected vs. healthy plants.

The findings suggest an active role for extracellular vesicles in plant immune responses, with fungal pathogen-derived proteins potentially triggering infection. The method's sensitivity and robustness enable accurate identification and quantification of numerous proteins even from limited sample amounts.