Nanodomain-localized formin gates symbiotic microbial entry in legume and solanaceous plants
Summary
Colonization of plant roots by symbionts requires substantial morphodynamic reorganization. Examples are actin-scaffolded microcompartments called infection pockets formed during root nodule symbiosis (RNS) by legumes. We demonstrate that the actin-binding formin SYFO2 is indispensable for rhizobial infection in Medicago truncatula, where it drives actin polymerization in phase-separated and symbiosis-specific nanodomains. SYFO2 also regulates symbiotically active arbuscules formed during
Content
# Nanodomain-localized formin gates symbiotic microbial entry in legume and solanaceous plants
*Published: 2026 Mar 5*
Colonization of plant roots by symbionts requires substantial morphodynamic
reorganization. Examples are actin-scaffolded microcompartments called infection
pockets formed during root nodule symbiosis (RNS) by legumes. We demonstrate
that the actin-binding formin SYFO2 is indispensable for rhizobial infection in
Medicago truncatula, where it drives actin polymerization in phase-separated and
symbiosis-specific nanodomains. SYFO2 also regulates symbiotically active
arbuscules formed during mycorrhizal symbiosis in plants outside the nodulating
clade, indicating that it was additionally recruited to promote rhizobial
infections in legumes. As part of our aim to enable nitrogen fixation in
nonlegumes, we activated endogenous SYFO2 by stably introducing the RNS master
regulator NODULE INCEPTION (NIN) into the natural nonhost tomato. This
demonstrates the possibility of recruiting arbuscular mycorrhizae-related genes
into an engineered nodulation-specific pathway.
DOI: 10.1126/science.adx8542