title: Patterns of shoot architecture in locally adapted populations are linked to intraspecific differences in gene regulation.
abstract: • Shoot architecture, including the number and location of branches, is a crucial aspect of plant function, morphological diversification, life history evolution and crop domestication. • Genes controlling shoot architecture are well characterized in, and largely conserved across, model flowering plant species. The role of these genes in the evolution of morphological diversity in natural populations, however, has not been explored. • We identify axillary meristem outgrowth as a primary driver of divergent branch number and life histories in two locally adapted populations of the monkeyflower, Mimulus guttatus. • Furthermore, we show that MORE AXILLARY GROWTH (MAX) gene expression strongly correlates with natural variation in branch outgrowth in this species, linking modification of the MAX-dependent pathway to the evolutionary diversification of shoot architecture.
authors.affiliation: Department of Ecology and Evolutionary Biology, Campus Box 334, University of Colorado at Boulder, Boulder, CO 80309, USA.|Current address: Department of Botany, University of Wyoming, Laramie WY 80271, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Baker
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045, USA.
authors.forename: Lena C
authors.initials: LC
authors.lastname: Hileman
authors.affiliation: Department of Ecology and Evolutionary Biology, Campus Box 334, University of Colorado at Boulder, Boulder, CO 80309, USA.
authors.forename: Pamela K
authors.initials: PK
authors.lastname: Diggle
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D032241:Mimulus / Q000033:anatomy & histology / Q000166:cytology / Q000235:genetics* / Q000502:physiology*; D008954:Models, Biological; D010641:Phenotype; D018520:Plant Shoots / Q000033:anatomy & histology* / Q000166:cytology / Q000235:genetics* / Q000648:ultrastructure; D013045:Species Specificity