title: Molecular mechanisms governing differential robustness of development and environmental responses in plants.
abstract: Robustness to genetic and environmental perturbation is a salient feature of multicellular organisms. Loss of developmental robustness can lead to severe phenotypic defects and fitness loss. However, perfect robustness, i.e. no variation at all, is evolutionarily unfit as organisms must be able to change phenotype to properly respond to changing environments and biotic challenges. Plasticity is the ability to adjust phenotypes predictably in response to specific environmental stimuli, which can be considered a transient shift allowing an organism to move from one robust phenotypic state to another. Plants, as sessile organisms that undergo continuous development, are particularly dependent on an exquisite fine-tuning of the processes that balance robustness and plasticity to maximize fitness.
  
  
  
  This paper reviews recently identified mechanisms, both systems-level and molecular, that modulate robustness, and discusses their implications for the optimization of plant fitness. Robustness in living systems arises from the structure of genetic networks, the specific molecular functions of the underlying genes, and their interactions. This very same network responsible for the robustness of specific developmental states also has to be built such that it enables plastic yet robust shifts in response to environmental changes. In plants, the interactions and functions of signal transduction pathways activated by phytohormones and the tendency for plants to tolerate whole-genome duplications, tandem gene duplication and hybridization are emerging as major regulators of robustness in development. Despite their obvious implications for plant evolution and plant breeding, the mechanistic underpinnings by which plants modulate precise levels of robustness, plasticity and evolvability in networks controlling different phenotypes are under-studied.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, 830 North University Avenue, Ann Arbor, MI 48197, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Lachowiec
authors.affiliation: Department of Genome Sciences, University of Washington, 3720 15th Avenue NE, Seattle, WA 98155, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Queitsch
authors.affiliation: Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA and DynaMo Center of Excellence, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark kliebenstein@ucdavis.edu.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kliebenstein
mesh_terms: D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly / Q000235:genetics; D056915:DNA Copy Number Variations; D018744:DNA, Plant; D004275:DNA, Ribosomal; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D018745:Genome, Plant; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D063245:Plant Development / Q000235:genetics* / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D002843:Chromatin; D018744:DNA, Plant; D004275:DNA, Ribosomal; D018841:HSP90 Heat-Shock Proteins; D010940:Plant Proteins
keywords: Developmental robustness; Hsp90; canalization; capacitor; chromatin; hormones; network hubs; network motifs; noise; plasticity; rDNA; redundancy; species diversity