SWEET transporter biosensors for high-throughput screening of plant disease inhibitors

Overview

Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a major rice disease responsible for substantial yield losses across Asia and Africa. The pathogen exploits sugar transporters of the SWEET family in rice to extract nutrients from host plants, enabling infection. This project proposes a new crop protection approach: instead of genetically modifying plants, small-molecule inhibitors could block SWEET transporter activity and reduce disease susceptibility. The research team is developing a high-throughput biosensor platform to discover such inhibitors from chemical libraries, with potential applications across multiple crops.

Technical specifications

Core technology:

• Intramolecular fusion proteins combining SWEET transporters with conformation-sensitive fluorescent proteins
• Designed to report small-molecule binding as changes in fluorescence intensity
• Expressed in microbial systems for rapid, parallel screening

Approach and rationale:

• Membrane transporters are well-established drug targets in human health; the team is applying a similar strategy to plant disease
• SWEETs are conserved across plant species, so inhibitors may have broad applicability beyond rice
• High-throughput screening enables evaluation of hundreds of small molecules efficiently
• Avoids the regulatory and public acceptance challenges associated with transgenic crops

Potential applications:

• Crop protection against bacterial blight and potentially other SWEET-dependent plant diseases
• Discovery of lead compounds for agrochemical development
• A generalizable platform for screening inhibitors of other plant transporters

Technology readiness level

The project is at an early research stage. The proposed biosensor system and high-throughput screening workflow have been conceptualized but not yet validated. Next steps include constructing the SWEET–fluorescent protein fusions, confirming that fluorescence responses correlate with small-molecule binding, and running pilot screens against chemical libraries. Successful validation would advance the platform toward lead compound identification and subsequent agrochemical development.