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ARS Home » Pacific West Area » Albany, California » Plant Gene Expression Center » Research » Publications at this Location » Publication #378418

Research Project: Characterization of Plant Architectural Genes in Maize for Increased Productivity

Location: Plant Gene Expression Center

Title: Evolution of the grass leaf by primordium extension and petiole-lamina remodeling

Author
item RICHARDSON, ANNIS - UNIVERSITY OF EDINBURGH
item CHENG, JIE - INSTITUTE OF BOTANY - CHINA
item JOHNSTON, ROBYN - CORNELL UNIVERSITY
item KENNAWAY, RICHARD - JOHN INNES CENTER
item CONLON, B - CORNELL UNIVERSITY
item REBOCHO, XANA - JOHN INNES CENTER
item KONG, H - CHINESE ACADEMY OF SCIENCES
item SCANLON, MICHAEL - CORNELL UNIVERSITY
item HAKE, SARAH
item COEN, ENRICO - JOHN INNES CENTER

Submitted to: Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2021
Publication Date: 12/10/2021
Citation: Richardson, A., Cheng, J., Johnston, R., Kennaway, R., Conlon, B., Rebocho, X., Kong, H., Scanlon, M., Hake, S.C., Coen, E. 2021. Evolution of the grass leaf by primordium extension and petiole-lamina remodeling. Science. 374(6573):1377-1381. https://doi.org/10.1126/science.abf9407.
DOI: https://doi.org/10.1126/science.abf9407

Interpretive Summary: Grass leaves are distinctly different than leaves of dicots with the sheath that clasps the stem and the blade that leans back for photosynthesis. In order to understand how a grass leaf grows, modeling was used in combination with maize mutants and gene expression patterns to infer the growth patterns. A mathematical model was developed that recapitulated normal maize leaf growth. With small changes to the model, maize mutants with narrow leaves could be phenocopied as well as a dicot leaf. The work provides the ground work for understand different leaf shapes.

Technical Abstract: The grass leaf is an evolutionary innovation contributing to the world-wide ecological success of grasses, yet its origin has been a subject of longstanding debate. Here we revisit the problem in the light of developmental genetics and computational modelling. We show that the grass leaf likely arose through extension of a primordial zone straddling concentric ad-abaxial domains in the shoot apex. Growth within this zone, subdivided into mediolateral and proximodistal domains, leads to wild-type; whereas zone truncation or compression accounts for mutant or eudicot leaf development. In contrast to the prevailing view, we propose that only the sheath of the grass leaf derives from petiole, whereas the blade derives from lamina, consistent with homologies proposed in the 19th century.