From Stem Cell to Tissue: Development at the Plant Shoot Apical Meristem

Abstract:
The shoot apical meristem of flowering plants is the stem cell niche that is the source of the above-ground parts of the plant, including stem, leaves and flowers. New flowers form at the meristem in a stereotyped pattern, the phyllotactic pattern. The specification of a new flower results from both chemical and mechanical signaling in the shoot apex, with feedbacks between chemical and physical signals that together act both in developmental pattern formation and in morphogenesis. Once a new flower is specified, it serves as a signaling center for the establishment of a provascular track from the flower primordium downward to the previously established shoot vascular system (which itself formed from earlier leaf and flower positions). The differentiating vasculature then serves as a signaling nexus that acts in control of continued flower development. The lecture will begin with the chemical and mechanical mechanism of selection of the position of new flowers, then proceed to the genetic, morphological and genomic interactions that specify the path of future vascular development in the undifferentiated cells of the upper stem, and to the signaling role of the differentiating vascular system in continued flower development.

About the Speaker:
Elliot Meyerowitz is the George Beadle Professor of Biology, and a Howard Hughes Medical Investigator at the California Institute of Technology, where he has been on the faculty since 1980. Prior to joining the Caltech faculty he obtained an undergraduate degree in Biology from Columbia University, and graduate degrees in Biology from Yale University, following which he was a postdoctoral fellow at the Stanford University School of Medicine.

From 2000 to 2010 he was Chair of the Caltech Division of Biology. In 2011 and 2012, while on leave from Caltech, he served as the Inaugural Director of the Sainsbury Laboratory at the University of Cambridge, was Professor of Plant Morphodynamics at the University of Cambridge, and was a Fellow of Trinity College, Cambridge.

The Meyerowitz laboratory studies the development of Arabidopsis thaliana, a widely used plant model system that his laboratory (and others) popularized beginning in the early 1980s. Current studies concentrate on the interrelated roles of mechanical and chemical signaling in plant morphogenesis.
Among Meyerowitz’s honors are the International Prize for Biology of the Japan Society for the Promotion of Science (1997); the Lounsbery Award of the National Academy of Sciences (1999); the R.G. Harrison Prize of the International Society of Developmental Biologists (2005); the Balzan Prize (2006); the Gruber Genetics Prize (2018) and the Wolf Prize in Agriculture (2024). Meyerowitz is a member of the American Academy of Arts and Sciences, the U.S. National Academy of Sciences and the American Philosophical Society. He is a foreign associate of the Académie des Sciences of France, and a foreign member of the Royal Society.

Contact

Keith Cheng
kcc2@psu.edu