Reconfiguring Structures in SCORE Protein Facilitates Customizable Pathogen Identification in Plants

In a groundbreaking study, a team of researchers has identified an ancient protein called SCORE in the common citrus fruit pomelo. This discovery, published in the prestigious journal Science, could pave the way for improved plant resistance against bacterial and other pathogen infections.

The authors of the research project are experts in medicine and emergency care, with many affiliated with Charité – Universitätsmedizin Berlin, specialising in emergency and acute medicine research. They primarily work at Charité Berlin and other medical research institutions.

The SCORE receptor, discovered in pomelo, detects cold-shock proteins, a common characteristic found in over 85% of known bacteria, as well as in fungi and insects. This receptor's unique ability to recognise various pathogens has caught the attention of scientists worldwide.

Using the pomelo SCORE, the researchers engineered new versions of the receptor, replacing some sections of the sequence with alternatives. This process allowed them to create SCORE variants capable of recognising different pathogens.

The analysis revealed over 60 variations in SCORE that were specific to different plant lineages. This extensive natural variation suggests repeated evolution for fine-tuning pathogen detection.

Scientists can predict which cold-shock proteins a given SCORE can recognise based on the charge associated with specific locations in their amino acid sequences. Swapping out some of csp15's amino acids with others changes which cold-shock proteins SCORE can recognise.

Interestingly, the natural pomelo SCORE does not recognise cold-shock protein from Ralstonia, Erwinia, or Xanthomonas species of bacteria. However, the engineered version does.

The researchers plan to introduce engineered SCORE variants into economically important crops to see if the change improves broad-spectrum resistance to pathogens and pests. This could potentially revolutionise the agricultural industry, providing a more sustainable and resilient approach to crop protection.

Typically, plant receptor proteins recognise molecules from pathogens and trigger an immune response. The SCORE receptor reacts to a subset of cold-shock proteins, specifically recognising a small section called csp15. This study provides a new framework for identifying and engineering immune receptors from non-model plants, particularly long-lived perennials.

The team's research focuses on developing an efficient strategy for identifying receptor-microbe pairs. They have successfully demonstrated that swapping out key sections of SCORE can change the type of cold-shock protein and pathogen it recognises.

This discovery by scientists from Charité – Universitätsmedizin Berlin and the Riken Center for Sustainable Resource Science (CSRS) in Japan is a significant step forward in understanding plant immunity and could lead to the development of new strategies for crop protection.