The Role of Endoreduplication in Mitigating the Detrimental Effects of Herbivory

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Endoreduplication is the replication of the genome without mitosis, which leads to endopolyploidy, an increase in cellular chromosome number. The process of endoreduplication occurs in nearly all herbaceous flowering plants, yet its primary function is unknown. Here Dr. Paige proposes to test a novel idea - that chromosome amplification can mitigate the detrimental effects of herbivory and lead to enhanced growth and reproduction. Previous studies by the Paige lab have shown a correlation between chromosome amplification, plant reproduction and herbivory, however, no direct causal links have been established. To establish a causal relationship he will use a suite of greenhouse and field studies to generalize the phenomenon within two species of plants, Arabidopsis thaliana and Ipomopsis aggregata, assess whether ILP1, a gene that regulates chromosome amplification, correlates with reproductive success following herbivory in A. thaliana and use knockout and overexpression mutants of ILP1 to establish a causal relationship between chromosome amplification, herbivory and reproductive success. If chromosome amplification leads to enhanced reproduction, such changes may be of an adaptive nature and widespread among plants in mitigating the detrimental effects of herbivory. Furthermore, gaining an understanding of the genetic basis of increased seed yield following herbivore damage should be of great interest to agriculturists who, through recent advents in genetic technology, might incorporate traits (such as ILP1 overexpression promoters) into crop plants such as oilseed rape (Brassica napus), a close relative of Arabidopsis that also amplifies chromosome number. He also suspects that these studies reach far beyond the interactions between plants and herbivores and may in fact represent a generalized response to all kinds of environmental stressors.