Little is known about how cell shape is controlled. We are using the morphogenesis of trichomes (plant hairs) on the plant Arabidopsis thaliana as a model to study how cell shape is controlled. Wild-type Arabidopsis trichomes are large, single epidermal cells with a stalk and three or four branches, whereas in zwichel (zwi) mutants the trichomes have a shortened stalk and only two branches. To ...

In this paper, we provide a historical account of the contribution of a single line of research to our current understanding of the structure of cis-regulatory regions and the genetic basis for morphological evolution. We revisit the experiments that shed light on the evolution of larval cuticular patterns within the genus Drosophila and the evolution and structure of the shavenbaby gene. We de...

Progeny from a transformed Arabidopsis plant (produced by the Agrobacterium-mediated seed transformation procedure) were found to be segregating for an altered trichome phenotype. The mutant plants have normal leaf trichomes but completely lack trichomes usually found on the stem. The mutation is tightly linked to a T-DNA insert. Complementation analysis with genetically characterized trichome ...

Multicellular glandular trichomes form on gynoecia of wild annual Glycine species, annual soybean cultivars, and wild perennial Glycine species. These trichomes occur from the ovary base to the style base and, in perennial species, along the style as well. Trichomes form at least 2 d before anthesis, and new trichomes develop throughout flowering and also on young seed pods. Trichome structure ...

Endoreplication, also known as endoreduplication, is a phyogenetically widespread modified version of the cell cycle in which DNA replication is not followed by cell division. The SIAMESE (SIM) gene of Arabidopsis thaliana encodes the founding member of a novel class of plant-specific cyclin-dependent kinase (CDK) inhibitors and is a key regulator of endoreplication during the development of tr...

Chromatin assembly factor CAF-1 facilitates the formation of nucleosomes on newly replicated DNA in vitro. However, the role of CAF-1 in development is poorly understood because mutants are not available in most multicellular model organisms. Biochemical evidence suggests that FASCIATA1, FASCIATA2 and MSI1 form CAF-1 in Arabidopsis thaliana. Because fasciata mutants are viable, CAF-1 is not ess...

Integration of diverse environmental and endogenous signals to coordinately regulate growth, development, and defense is essential for plants to survive in their natural habitat. The hormonal signals gibberellin (GA) and jasmonate (JA) antagonistically and synergistically regulate diverse aspects of plant growth, development, and defense. GA and JA synergistically induce initiation of trichomes...

In this study we produced transgenic tobacco plants by overexpressing a serine proteinase inhibitor gene, SaPIN2a, from the American black nightshade Solanum americanum under the control of the CaMV 35S promoter using Agrobacterium tumefaciens-mediated transformation. SaPIN2a was properly transcribed and translated as indicated by Northern blot and Western blot analyses. Functional integrity of...

Trichomes, or leaf hairs, are epidermal extensions that take a variety of forms and perform many functions in plants, including herbivore defence. In this study, I document genetically determined variation, within-generation plasticity, and a direct role of trichomes in herbivore defence for Mimulus guttatus. After establishing the relationship between trichomes and herbivory, I test for transg...

Microtubules (MTs) and actin filaments (F-actin) function cooperatively to regulate plant cell morphogenesis. However, the mechanisms underlying the crosstalk between these two cytoskeletal systems, particularly in cell shape control, remain largely unknown. In this study, we show that introduction of the MyTH4-FERM tandem into KCBP (kinesin-like calmodulin-binding protein) during evolution con...