Work

Pan-eukaryotic distribution and deep homology of plant small secreted peptides and their receptors

Year: 2026

Type: article

Abstract: Small secreted peptides (SSPs) are essential signaling molecules in plants, yet their deep evolutionary origins remained unclear. Here, we integrated sensitive homology searches with rigorous filtering to systematically identify SSP and leucine-rich repeats receptor-like kinase (LRR-RLK) homologs across the EukProt database. We recovered 59 high-confidence SSP homologs from diverse deeply branching eukaryotic supergroups, with protistan sequences consistently placed at the base of phylogenies. Parallel searches recovered 916 LRR-RLKs from non-vascular plant lineages, whereas the SSP-associated XI subfamily was largely confined to Archaeplastida. Co-occurrence of SSPs and LRR-RLKs in 6 lineages, together with bidirectional motif traceability revealing strong purifying selection on core residues, supports a model in which core components of SSP signaling emerged early in eukaryotic evolution and were vertically inherited, with subsequent lineage-specific diversification and co-option during streptophyte evolution. Our study provides a revised evolutionary framework for plant peptide signaling and a broadly applicable strategy for tracing ancient origins of lineage-specific innovations.

Source: iScience

DOI: 10.1016/j.isci.2026.115540

Authors: Zhe Zhang, Songqing Yue, Fahu Yuan, Miaomiao Zhu

Institutions: Jianghan University, Huazhong Agricultural University, Wuhan Children's Hospital, Huazhong University of Science and Technology

Language: English

Topic: Plant Molecular Biology Research

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $3,240

Funders: Natural Science Foundation of Hubei Province, Jianghan University