# Comparative Metabolomic Profiling of Resistant and Susceptible Coffea arabica Accessions to Bacterial Pathogen Infection

## TL;DR

This study compares the chemical profiles of coffee plants that resist and those that are vulnerable to a bacterial disease, identifying potential markers of resistance.

## Contribution

The study identifies specific metabolites associated with resistance to bacterial blight in Coffea arabica, offering new insights into plant defense mechanisms.

## Key findings

- Flavonoids were more abundant in susceptible coffee leaves.
- Resistant leaves had higher levels of pipecolic acid ethyl ester and spiropreussione B.
- The findings suggest systemic signaling and microbial interactions may enhance resistance.

## Abstract

Coffea, a plant species of significant agricultural value used in coffee production, is a key commodity that supports the livelihoods of millions of people worldwide. However, coffee cultivation faces substantial threats from various pathogens, including Pseudomonas coronafaciens pv. garcae (Pcg), the causative agent of bacterial blight. This pathogen compromises coffee plant health, leading to reduced yields and plant death and impacting farmers and large-scale producers. Understanding the mechanisms underlying resistance to Pcg in the leaves of the resistant IAC 2211-6 Coffea arabica accession is crucial for developing effective control strategies. This study aimed to identify candidate biomarkers of resistance by comparing the leaf metabolome of (i) the resistant IAC 2211-6 and the susceptible IAC 125 RN Coffea arabica accessions and (ii) Pcg-infected and uninfected leaves. Untargeted metabolomics revealed distinct metabolic profiles between accessions. Flavonoids were more abundant in susceptible leaves. In contrast, resistant leaves showed increased levels of pipecolic acid ethyl ester, a structural derivative of a key systemic acquired resistance signal, and spiropreussione B, a compound associated with fungal endophytes. These findings highlight candidates potentially linked to resistance and suggest that systemic signaling and beneficial microbial interactions may contribute to resilience.