OVERVIEW

Although the mechanism of coral bleaching, i.e. dysbiosis between cnidarian host and algal endosymbionts, is not fully known, it is understood that a combination of excess free-radicals, a deficient antioxidant system and innate immune responses are central to the breakdown of symbiosis through cellular damage. The symbiosis between reef-building corals and dinoflagellate algae is at the center of tropical marine ecosystems which support a biodiversity rivaling that of rainforests, an economy worth US$36 billion and over 1 billion people. Environmental stress threatens symbiosis equilibrium, regulatory crosstalk, partner recognition and nutritional exchanges between host and symbiont. Recurrent mass bleaching events recorded for the last two decades have left coral reefs highly degraded, putting in question their survival past 2050. Current conservation and restoration efforts are hindered by a gap in our understanding of the molecular, cellular and microenvironmental dynamics of symbiotic dysbiosis and coral bleaching. Here we propose to integrate recent advances in cellular-level coral research, nanobiotechnology and engineering with gene expression and metabolomics to elucidate the dynamics of free-radical stress (also known as nitro-oxidative stress) and dysbiosis in cnidarian-dinoflagellate mutualistic symbiosis. While the intricacies of the coral holobiont (i.e. the coral host and its complex microbiome, algal symbiont included) are challenging because of all potential interactions between partners, our approach will strive to understand each partner’s involvement in the accumulation of free- radicals during stress on spatial scales ranging from molecules to cells and tissues to organisms. To this end, the proposed project will: (Aim 1) characterize free-radical spatio-temporal dynamic in isolation and in symbiosis; (Aim 2) characterize the cellular responsiveness to controlled, targeted nitro-oxidative stress; and (Aim 3) manipulate and track the response to nitro-oxidative stress in a 3D bionic coral model.

link to NSF award

Project co-PIs: Hollie Putnam & Daniel Wangpraseurt