The microbial and chemical terroir of agarwood in French Guiana

Agarwood is a highly valued aromatic resinous wood formed in Aquilaria species following stress or infection, yet the putative microbial drivers of its chemical quality remain poorly understood, particularly outside its native range. In this study, we investigated the bacterial and fungal communities associated with agarwood produced from Aquilaria crassna Pierre ex Lecomte planted in French Guiana and examined their relationships with volatile chemical compounds relevant to agarwood fragrance. Using high‑throughput sequencing and comprehensive chemical profiling, we characterized microbial community composition and agarwood volatile profiles across multiple cultivation plots. Despite spatial variability in microbial assemblages, agarwood samples exhibited a conserved chemical signature dominated by chromone derivatives and sesquiterpenoids, indicating the presence of a stable chemical terroir under Guianese environmental conditions. Network analysis revealed numerous bacterial and fungal taxa significantly associated with key chemical classes, suggesting potential microbial contributions to agarwood chemical complexity through plant–microbe interactions or microbial metabolic activity, although causality remains to be established. Comparative analyses with commercial agarwood samples from South-East Asia and the Middle East revealed a distinct chemical profile for Guianese agarwood, highlighting the influence of geographic origin on agarwood quality and supporting an extension of the terroir concept to woody aromatic products. Overall, this study demonstrates that Aquilaria trees cultivated in French Guiana can produce high‑quality agarwood and provides new insights into the interplay between microbial communities and agarwood chemistry. These findings lay the groundwork for the development of locally adapted, microbiome‑informed strategies for sustainable agarwood production.