Characterization of heavy metal bioremediation pathways in local moss species

Heavy metals are found in natural water sources and are toxic to plants and animals. Metal removal remains a goal of environmental protection; one promising approach is to use plants that have been genetically modified to better remove metals from water. A known metabolic pathway to neutralize metals uses the Phytochelatin Synthase (PCS) enzyme to catalyze the production of phytochelatins. Our research characterizes the potential of Indiana moss species for heavy metal bioremediation as foundational research for future genetic modification. Mosses grow well in water and absorb metals through their entire surface area, and using locally collected moss species will ensure that any future genetically modified organisms developed for bioremediation are well adapted to the local environment. To determine factors involved in heavy metal response and phenotypic variance, we measured survival and heavy metal uptake of three local moss species after growth in various doses of copper, cobalt, and cadmium sulfates. A three-way ANOVA showed no significant effect of metal identity, metal dose, or moss species on chlorophyll levels, indicating no survival advantage for any moss in any metal or any dose. A separate three-way ANOVA showed significant effects of metal identity, metal dose, and moss species on metal absorbance rate, indicating the need to select a specific moss to best absorb a particular metal at a particular dose. Future work will probe for and sequence PCS genes in several local moss species. This study of moss phenotypic and genetic response to heavy metals is a prerequisite to the development of a moss genetically modified for bioremediation