Mackenzie Lab at The Pennsylvania State University – Departments of Biology and Plant Science

Our laboratory investigates how nuclear genes interact with mitochondria and plastids to control plant growth and environmental responses. We study the role of nuclear genes in directing tissue-specific organelle behaviors that can transition plants between pollen fertile and sterile states, or elicit environmental stress responses that can be inherited by their progeny. One nuclear gene discovered by our group and unique to plants is MSH1. This gene is present in all green plants, but is not found in fungal or mammalian lineages. Expression of MSH1 is influenced by environmental conditions, and its suppression by stress can produce changes in mitochondrial and chloroplast behavior and in plant growth patterns. We are learning how MSH1, and other proteins that function with MSH1, might have evolved as a plant system that to condition plant phenotypic plasticity.

A model of msh1 (red dot) and ppd3 (blue dot) influence on sensory plastid signal and plant phenotype. The model postulates that stress (1) leads to MSH1 suppression (2), triggering plastid genome instability (3) and redox changes (4). Plastid genome instability can cause changes in nuclear genome behavior. Stress and redox changes lead to plastid stromule production and perinuclear association (5). Nuclear genome response includes chromatin remodeling and changes in targeted gene pathways to alter phenotype (6).

Our studies include Arabidopsis, tomato, soybean, sorghum and canola. Students benefit from the opportunity to include comparative genomic and field studies to their research. All projects in the lab integrate molecular biology, cell biology, genetics, epigenomics, computational biology and phylogenetic approaches in their research plans. Computational studies include proteomic analyses of plastid differentiation, genome-wide methylation patterning, and gene network analysis.

Collaborations

Epicrop Technologies: http://www.epicrop.com/

We collaborate with EpiCrop to learn new ways to implement epigenetics into crop improvement.