Talline Martins

Department of Botany

430 Lincoln Drive

University of Wisconsin

Madison, WI 53706-1381

Office: 220 Birge Hall
Phone: (608) 265-7929

Fax: (608) 262-7509
Email: tmartins@wisc.edu

Educational Background:

BS Biology, Western Michigan University, 2005

Research Interests:

Plant evolutionary and developmental genetics, speciation, genetics of adaptation.

Hobbies:

Reading, dancing, cooking, going to the farmer's market, sampling traditional Wisconsin beverages and food.

Current Projects:

Evolution of Floral traits: Dissecting the Genetic Basis for Petal Spot Polymorphism in Clarkia gracilis.

Clarkia gracilis subspecies from L to R: ssp. albicaulis, gracilis, sonomensis, and tracyi.

Project summary:

My project focuses on using a combination of molecular, biochemical, and genetic approaches to understand the genetic basis for the evolution flower spot polymorphism in Clarkia gracilis.  Floral color plays a central role in plant-pollinator communication, and numerous studies have found that variation in the production or pattern of floral pigmentation can greatly affect pollinator behavior and plant fitness, which may be critical facets in speciation. 

Clarkia gracilis (Onagraceae) is an annual plant species endemic to northwestern North America, which includes four subspecies, C. g. ssp. albicaulis, C. g. ssp. gracilis, C. g. ssp. sonomensis, and C. g. ssp. tracyi.  Amid the chief morphological characteristics differentiating the four subspecies is the presence/absence and location of a purple spot on each petal (see photos).  Ecological studies in populations of ssp. sonomensis showed that plants with petal spots produces as much as 30% more seed than unspotted plants (Jones 1996), suggesting that petal spots may provide a selective advantage over an absence of spots. 

            Work in a number of other species has shown that evolutionary changes in the production of anthocyanin pigments is usually due to changes in the expression and/or activity of genes involved in anthocyanin biosynthesis.  I hypothesize that the gene responsible for presence of the basal petal spot in C. gracilis encodes an anthocyanin biosynthetic gene or a regulator of those genes.   I am testing this hypothesis by studying the expression of genes in the anthocyanin biosynthetic pathway and their regulators and by testing whether any of the genes are genetically linked to the previously identified Mendelian locus. This will allow me to further characterize the molecular changes involved and may open the door to studying other floral pigment variation in Clarkia (e.g., petal spot positioning) and analogous phenotypes in other taxa.  Such work could shed light on how changes at the biochemical level can influence ecologically important phenotypes.

Martins, T. R., Stout, J., Todd, S. E., Kuipers, K., and T. J. Barkman.  (in press). Molecular phylogenetic tests of floral scent evolution in the Solanaceae.  Acta Horticulturae.  

Barkman, T. J., Martins, T. R., Sutton, E., and Stout, J. 2007. Positive Selection for Single Amino Acid Change Promotes Substrate Discrimination of a Plant Volatile-Producing Enzyme.  Molecular Biology and Evolution 24(6):1320-1329.

Martins, T. R. and T. J. Barkman. 2005. Reconstruction of Solanaceae Phylogeny using the nuclear gene SAMT.  Systematic Botany 30(2).