Graduate Student Seed Grant Projects

Ploidy plasticity: exploring novel mechanisms of stress tolerance in a global invader

Investigators:

Alyssa Smith, Plant Pathology, Physiology, & Weed Science; Faculty Mentors: Jacob Barney and David Haak, Plant Pathology, Physiology, & Weed Science


Some plant species respond to environmental stress through a form of genotypic plasticity called “endoreduplication”. Endoreduplication is a replication of the genome without cell division, which increases chromosome number (ploidy) and cell size, but the degree to which it is adaptive is poorly understood. Previous research indicates that endoreduplication is correlated with strong growth responses to simulated herbivory.

johnsongrass

Johnsongrass trials in the greenhouse

Sorghum halepense (Johnsongrass) is a highly aggressive agricultural weed and invader of natural systems, but few mechanisms explain its widespread success.  We propose to conduct experiments in which S. halepense is exposed to stresses of herbicides, physical damage, and competition, and then compare cellular endoreduplication occurring in stressed plants to that in control plants using flow cytometry.  We will perform three experiments to examine the possible role of endoreduplication in stress tolerance.

This research will shed light on an important and poorly understood mechanism through which plants cope with stress. Our study will also provide a useful source of genomic information on one of the world’s most invasive species.