# The Host Coral Bleaching Response Viewed Through the Lens of Multi‐Omics: Multi‐Omics Provides the Tools to Understand the Complex Molecular Basis of Coral Bleaching, Which Can Aid Conservation Efforts

## TL;DR

This paper reviews multi-omics studies to understand how corals respond to heat stress and bleaching, aiming to improve conservation strategies.

## Contribution

The study introduces a 'personal genomics' approach to coral conservation based on multi-omics data and host genotype-specific responses.

## Key findings

- Coral bleaching is a multifactorial response influenced by host genotype, ploidy, and local adaptation.
- Multi-omics data reveal that transcript changes are most impacted by coral genotype and environment.
- The Oxidative Theory of Coral Bleaching is supported as a defense mechanism against algal oxidative stress.

## Abstract

We review recent multi‐omics analyses of the coral heat stress response to explore the generality of the Oxidative Theory of Coral Bleaching (OTCB), which posits that algal symbiont release is the final act of defense by the coral host to survive alga‐derived oxidative stress. The OTCB is particularly relevant given that ocean warming, which is accelerating under climate change, has proven devastating for corals, leading to the bleaching phenotype and widespread reef loss. Multi‐omics results, in combination with other data, such as genome‐wide association studies, support the idea that coral bleaching is a multifactorial response that reflects a wide array of causes and effects and is population‐specific under most conditions, with coral ploidy and genotype being critical to bleaching sensitivity. This perspective leverages the location, algal and prokaryotic microbiome, and host genotype‐specific aspects of coral resilience to promote a new “personal genomics” approach to coral conservation, analogous to that used in human health.

Coral bleaching is driven by multiple inputs, with heat stress and/or high irradiance being most important. The bleaching response is multifactorial with host animal species/strain and algal symbiont genotypes being critical features. Omics readout of heat stress responses includes gene expression, proteomics, metabolite, and SNP data with transcript changes most impacted by genotype and local adaptation.