title: Seed Production Affects Maternal Growth and Senescence in Arabidopsis.
abstract: Correlative control (influence of one organ over another organ) of seeds over maternal growth is one of the most obvious phenotypic expressions of the trade-off between growth and reproduction. However, the underlying molecular mechanisms are largely unknown. Here, we characterize the physiological and molecular effects of correlative inhibition by seeds on Arabidopsis (Arabidopsis thaliana) inflorescences, i.e. global proliferative arrest (GPA) during which all maternal growth ceases upon the production of a given number of seeds. We observed transcriptional responses to growth- and branching-inhibitory hormones, and low mitotic activity in meristems upon GPA, but found that meristems retain their identity and proliferative potential. In shoot tissues, we detected the induction of stress- and senescence-related gene expression upon fruit production and GPA, and a drop in chlorophyll levels, suggestive of altered source-sink relationships between vegetative shoot and reproductive tissues. Levels of shoot reactive oxygen species, however, strongly decreased upon GPA, a phenomenon that is associated with bud dormancy in some perennials. Indeed, gene expression changes in arrested apical inflorescences after fruit removal resembled changes observed in axillary buds following release from apical dominance. This suggests that GPA represents a form of bud dormancy, and that dominance is gradually transferred from growing inflorescences to maturing seeds, allowing offspring control over maternal resources, simultaneously restricting offspring number. This would provide a mechanistic explanation for the constraint between offspring quality and quantity.
authors.affiliation: Department of Evolutionary Biology and Environmental Studies and Zurich-Basel Plant Science Center, 8057 Zurich, Switzerland (S.E.W., B.S.); andDepartment of Plant and Microbial Biology and Zurich-Basel Plant Science Center, 8008 Zurich, Switzerland (S.E.W., M.A.P., D.G., U.G.) samuel.wuest@ieu.uzh.ch.
authors.forename: Samuel Elias
authors.identifier: 0000-0003-3982-0770
authors.initials: SE
authors.lastname: Wuest
authors.affiliation: Department of Evolutionary Biology and Environmental Studies and Zurich-Basel Plant Science Center, 8057 Zurich, Switzerland (S.E.W., B.S.); andDepartment of Plant and Microbial Biology and Zurich-Basel Plant Science Center, 8008 Zurich, Switzerland (S.E.W., M.A.P., D.G., U.G.).
authors.forename: Matthias Anton
authors.initials: MA
authors.lastname: Philipp
authors.affiliation: Department of Evolutionary Biology and Environmental Studies and Zurich-Basel Plant Science Center, 8057 Zurich, Switzerland (S.E.W., B.S.); andDepartment of Plant and Microbial Biology and Zurich-Basel Plant Science Center, 8008 Zurich, Switzerland (S.E.W., M.A.P., D.G., U.G.).
authors.forename: Daniela
authors.initials: D
authors.lastname: Guthörl
authors.affiliation: Department of Evolutionary Biology and Environmental Studies and Zurich-Basel Plant Science Center, 8057 Zurich, Switzerland (S.E.W., B.S.); andDepartment of Plant and Microbial Biology and Zurich-Basel Plant Science Center, 8008 Zurich, Switzerland (S.E.W., M.A.P., D.G., U.G.).
authors.forename: Bernhard
authors.identifier: 0000-0002-8430-3214
authors.initials: B
authors.lastname: Schmid
authors.affiliation: Department of Evolutionary Biology and Environmental Studies and Zurich-Basel Plant Science Center, 8057 Zurich, Switzerland (S.E.W., B.S.); andDepartment of Plant and Microbial Biology and Zurich-Basel Plant Science Center, 8008 Zurich, Switzerland (S.E.W., M.A.P., D.G., U.G.).
authors.forename: Ueli
authors.identifier: 0000-0002-0522-8974
authors.initials: U
authors.lastname: Grossniklaus
mesh_terms: D017360:Arabidopsis / Q000254:growth & development* / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D056626:Inflorescence / Q000235:genetics; D018519:Meristem / Q000235:genetics / Q000502:physiology; D018520:Plant Shoots / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000254:growth & development*
chemical_list: D017382:Reactive Oxygen Species