A combined omics approach to elucidate the molecular interplay behind a beneficial Arabidopsis-Caulobacter interaction

ABSTRACT: Plants rely on complex signaling networks to regulate growth and to interact with their environment, including beneficial microbes such as plant growth–promoting rhizobacteria (PGPR). Among these microbes, Caulobacter RHG1 has been shown to enhance plant growth and is recognized by Arabidopsis roots via specific receptor-like kinases (RLKs), but the molecular mechanisms underlying the plant growth-promotion effect remain largely unknown. To investigate these mechanisms, we used an integrative approach combining proteomics and phosphoproteomics to explore how RHG1 stimulates growth in Arabidopsis thaliana. Our phosphoproteome analysis revealed that RHG1 triggers a range of signaling events in the root, involving two RLKs (LysM RLK1-INTERACTING KINASE 1 [LIK1] and an uncharacterized RLK, AT5G49770). Notably, via the proteome analysis, we revealed that upon RHG1 treatment, defense proteins are downregulated early. Later on, developmental processes, such as those related to ribosome biogenesis and maturation, are involved in the growth-promotion effect and might lead to enhanced cell division and/or activity. These findings suggest that RHG1 is perceived at the root-level and this, via phosphorylation-based signaling pathways, triggers early protein-based effects that are characterized by timely modulation of defense and developmental processes, which eventually lead to plant growth promotion. Our data, combined with that of previous reports, points to the involvement of multiple signaling pathways, suggesting that RHG1 activates a broad network of regulatory mechanisms that extend beyond a single pathway. Understanding the mechanisms behind such beneficial plant-microbe interactions can pave the way for more effective commercialization of PGPR-based agricultural products, and our approach offers valuable insights for future research in this field.

INSTRUMENT(S):

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Root

SUBMITTER: Shao-Li Yang  

LAB HEAD: Sofie Goormachtig

PROVIDER: PXD066978 | Pride | 2026-04-14

REPOSITORIES: Pride