# Bioluminescent imaging of an oomycete pathogen empowers chemical selections and rational fungicide applications

## TL;DR

This study uses bioluminescent imaging to track a plant pathogen in real time, enabling better fungicide screening and application.

## Contribution

A genetically modified pathogen strain with luciferase enables real-time monitoring and high-throughput fungicide screening.

## Key findings

- A bioluminescent Phytophthora infestans strain (PiLuc) was developed for real-time pathogen tracking.
- A 96-well high-throughput screening system was created using PiLuc for compound efficacy assessment.
- Bioluminescence imaging allowed visualization of pathogen in potato tissues during early infection.

## Abstract

Fungicides play an indispensable role in ensuring food security. However, rational chemical selection and fungicide precision application guidance remain constrained by the limitations in real-time monitoring of tracking pathogens within plant tissues. In the current study, we generated a genetically stable Phytophthora infestans strain (PiLuc) expressing luciferase gene, which serves as a dual-mode quantification platform for both in vitro and in vivo throughput screening. Consequently, we designed a 96-well plate high-throughput screening system to assess compounds inhibitory efficacy using PiLuc. Crucially, bioluminescence imaging enabled visualization of PiLuc in potato leaves and tubers during early infection stage, which is invisible to the naked eye. Capitalizing on the semi non-destructive and visual advantages, we developed a system for fungicide bioavailability evaluation and dosage-response assessment in tuber tissues, integrating real-time dynamic monitoring of pathogen. The development of bioluminescent imaging of late blight pathogen establishes an enabling platform for high-throughput fungicide screening while improving the precision bioavailability assessments.

The online version contains supplementary material available at 10.1186/s13007-025-01374-9.