A single-cell blueprint for cellular diversity in the Green Lineage

Authors: COATE, JEREMY - Reed College; DOYLE, JEFF - Cornell University; FARMER, ANDREW - National Center For Genome Resources; HUANG, SHAO-SHAN - New York University; KAJALA, KAISA - Utrecht University; KENCHANMANE RAJU, SUNIL - University Of California, Riverside; KUMARI, SUNITA - Cold Spring Harbor Laboratory; PALFALVI, GERGO - Max Planck Institute For Plant Breeding Research; RADIN, IVAN - University Of Minnesota; NIKOLOV, LACHEZAR - Indiana University; SINGH, PALLAVI - University Of Essex; STATA, MATT - Michigan State University; YAO, QUIMING - University Of Nebraska; Ware, Doreen

Submitted to: Current Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2026
Publication Date: 6/8/2026
Citation: Coate, J.E., Doyle, J.J., Farmer, A., Huang, S.C., Kajala, K., Kenchanmane Raju, S.K., Kumari, S., Palfalvi, G., Radin, I., Nikolov, L.A., Singh, P., Stata, M., Yao, Q., Ware, D. 2026. A single-cell blueprint for cellular diversity in the Green Lineage. Current Biology. 36(11):PR577-R589. https://doi.org/10.1016/j.cub.2026.04.003.
DOI: https://doi.org/10.1016/j.cub.2026.04.003

Interpretive Summary: Plants, from tiny algae to giant redwood trees, evolved from a single ancestor over 1.5 billion years ago when an ancient cell engulfed a photosynthetic bacterium. This review explores how new technologies that study individual plant cells are revealing exciting insights about how plants work and evolved. Plant cells are fundamentally different from animal cells. They have chloroplasts for photosynthesis, large water-filled vacuoles, rigid cell walls, and tiny channels (plasmodesmata) that connect neighboring cells. Unlike animal cells that are locked into specific fates early in development, plant cells are remarkably flexible. They can change their identity based on their position and environmental conditions like drought or nutrient availability. The review explains how new plant cell types evolve. Rather than inventing entirely new genes, evolution mostly rewires existing genetic programs. For example, C4 photosynthesis evolved when bundle sheath cells "borrowed" genes from mesophyll cells and used them in new ways. Understanding plant cell diversity at this detailed level has major implications from understanding how life evolved to improving crops for feeding a growing human population in our changing climate.

Technical Abstract: The Green Lineage (Virdiplantae) represents one of the most successful evolutionary radiations on Earth, with remarkable morphological diversity from unicellular algae to complex multicellular land plants. Recent advances in single-cell genomics have transformed our understanding of plant cell type diversity and evolution, revealing fundamental principles underlying cellular organization and specification. This review synthesizes current knowledge of plant cell type identity and evolution through the lens of single-cell approaches. We examine how plant cell types are specified through combinatorial transcription factor networks analogous to animal terminal selector systems, yet operating within a fundamentally different developmental framework characterized by positional determination, extensive plasticity, and environmental responsiveness. We highlight unique features of plant cells including plastids, large vacuoles, cell walls, and plasmodesmata that profoundly influence cellular identity and present distinct challenges for single-cell profiling. Comparative analysis across the Green Lineage reveals that new cell types arise through subfunctionalization following gene and genome duplications, co-option of ancestral gene regulatory networks, and cis-regulatory evolution driven by transposable elements. We address major analytical challenges, including orthology assignment in polyploid genomes, cross-species dataset integration, gene regulatory network reconstruction and functional validation in diverse plant systems. Despite these challenges, plant single-cell genomics offers unprecedented opportunities to understand cellular evolution, with implications extending from fundamental biology to agricultural innovation.