# To win the battle: the chloroplast is a key battleground in plant–pathogen interactions

## TL;DR

This review highlights how chloroplasts are crucial in plant immunity and how pathogens target them to weaken plant defenses.

## Contribution

The paper provides a comprehensive overview of how pathogen effectors manipulate chloroplasts to enhance their pathogenicity.

## Key findings

- Chloroplasts play a key role in plant immunity through ROS production and hormone signaling.
- Pathogens use effectors to target chloroplasts and disrupt plant defense mechanisms.
- Understanding chloroplast manipulation by pathogens reveals new insights into plant immunity.

## Abstract

The interaction between plants and pathogens represents a complex evolutionary arms race. Plants employ a sophisticated innate immune system to combat pathogen invasion. However, pathogens inhibit plant immunity by secreting effectors into the host cell. The chloroplast is an indispensable organelle for photosynthesis and metabolism in plants. Notably, increasing evidence has recently revealed the pivotal role of chloroplasts in plant immunity, including reactive oxygen species production, phytohormone biosynthesis, and signal transduction. Accordingly, chloroplasts have emerged as key targets for pathogen effectors. In this review, we summarize the role of chloroplasts in plant immunity and update the identification of pathogen effectors that enhance pathogenicity by targeting chloroplasts. We also discuss the diverse mechanisms by which pathogen effectors hijack chloroplasts to manipulate plant immunity, shedding light on the functional complexity and importance of chloroplasts in plant–pathogen interactions.