Welcome to the Lukens Laboratory

We are investigating a variety of questions in the areas of molecular and quantitative genetics. Our research effort focuses on maize as well as rapeseed and its relatives. These questions include:

Global patterns and regulation of gene expression in plants

Maintaining a precise level and catalogue of gene transcripts is critical for normal plant development and environmental response. What factors control and create transcript levels and patterns? In what ways are transcript levels among different genes correlated? Are gene transcript levels primarily correlated because of cis regulatory sequences or do other factors such as genome position play a key role? How much does gene expression differ among different plants of the same species?

Effect of diverse germplasm and pedigree structure on quantitative traits

One can develop plants with novel traits if one crosses two, unrelated individuals or if one recombines existing genes from related individuals to generate a novel combination of genes. We are interested in the processes that generate and maintain these new types. In one project, we are investigating how introducing a wild relative's genes into rapeseed affects herbivore resistance. Are large segments of the distantly related genome maintained in the rapeseed genome? Are the introgressed genes that affect herbivory likely the same as in the model species Arabidopsis thaliana? In a second project, we are comparing two corn populations that harbor the same genes, but in one population the genes are intermixed more than the other. Are the plant populations that have undergone more gene intermixing more diverse as expected? Is the genetic basis of traits identical between the two populations?

Plant growth under water stress

Plants within the same species respond to and recover from water stress in different ways. While some plants can continue a relatively high rate of growth under mild water stress, other plants may cease to grow altogether. What is the genetic basis for these differences? Are the differences due to differences in osmotic adjustment or to changes in plant cell walls? Does the regulation of key genes explain why some plants do or do not continue to grow under stress?

The effect of polyploidization on plant genome structure

Many wild and commercially important plant species have genomes with four or more copies of similar chromosomes. What occurs within the plant genome in response to chromosomal duplication? Do the chromosome sets peacefully co-exist or is there widespread chromosomal change? Over time, are duplicated genes lost or do they gain new functions?