Roessner, C. | bioRxiv Science

bioRxiv2025

MIK2 clade receptor function in perception of a Fusarium-derived elicitor is conserved among different plant families

Plants continuously monitor their environment to adapt to threats affecting health and fitness. Cell-surface receptors detect conserved microbe-associated molecular patterns (MAMPs) or endogenous immunogenic signals to activate signaling pathways that induce broad-spectrum disease resistance, known as pattern-triggered immunity (PTI). In Arabidopsis thaliana, the leucine-rich repeat receptor kinase MIK2 emerged as a versatile receptor involved in perceiving endogenous SCOOP peptides as well as potential MAMPs derived from Fusarium and related fungi. While SCOOP perception appears restricted to Brassicales, the Fusarium-derived elicitor triggers PTI-responses across different plant lineages. Here, we demonstrate that Fusarium elicitor-responsiveness and MIK2-clade proteins are conserved among seed plants. We identified a tomato MIK2-clade receptor that shares AtMIK2 properties in perceiving the Fusarium elicitor, but not SCOOPs. Tomato mutants lacking the receptor show compromised PTI-responses to the fungal elicitor and increased susceptibility to Fusarium oxysporum. By integrating AI-assisted structural prediction with experimental data, we identify conserved and variable residues in Arabidopsis and tomato MIK2-clade receptors that may underlie shared and lineage-specific recognition specificities. Together, these findings establish MIK2-clade receptors as immune surveillance modules that have undergone lineage-specific diversification, supporting a model in which endogenous danger perception might have evolved from an ancestral role in microbial pattern recognition.

plant biology↗

bioRxiv2020

High-resolution temporal transcript profiling during Arabidopsis thaliana gynoecium morphogenesis uncovers the chronology of gene regulatory network activity and reveals novel developmental regulators

The gynoecium is the most complex organ formed by the flowering plants. It encloses the ovules, provides a surface for pollen contact and self-incompatibility reactions, allows pollen tube growth and, post fertilization, and develops into the fruit. Consequently, the regulation of gynoecium morphogenesis is complex and appropriate timing of this process in part determines reproductive success. However, little is known about the global control of gynoecium development, even though many regulatory genes have been characterized. Here, we characterized dynamic gene expression changes using laser-microdissected gynoecium tissue from four developmental stages in Arabidopsis. We provide a high-resolution map of global expression dynamics during gynoecium morphogenesis and link these to the gynoecium interactome. We reveal groups of genes acting together early and others acting late in morphogenesis. Clustering of co-expressed genes enables comparisons between the leaf, shoot apex, and gynoecium transcriptomes allowing the dissection of common and distinct regulators. Furthermore, our results lead to the discovery of the LESSER FERTILITY1-4 (LEF1-4) genes, which, when mutated, lead to impaired gynoecium expansion, illustrating that global transcriptome analyses reveal yet unknown developmental regulators. Our data show that highly interacting proteins, such as SEPALLATA3, AGAMOUS, and TOPLESS are expressed more evenly during development, but switch interactors in time, whereas stage-specific proteins have only few interactors. Our analysis connects specific transcriptional regulator activities, protein interactions, and underlying metabolic processes towards the development of a dynamic network model for gynoecium development.

plant biology↗