This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A research team led by the Australian Institute of Marine Science (AIMS) has found that heat-evolved algae maintain more stable biomolecular profiles under elevated temperatures than their non-evolved (wild-type) counterparts, providing new insights into how they withstand heat stress. The findings, published in New Phytologist, could help scientists develop new approaches to improve coral resilience in a warming climate.
Coral reefs, such as the Great Barrier Reef, depend on microscopic algae living inside their tissues. These algae can occur at densities of around 1 million cells per square centimeter of coral tissue and provide much of the energy corals need to survive. However, rising ocean temperatures can disrupt this relationship, leading to coral bleaching.
Previous research has shown that algae experimentally evolved to tolerate higher temperatures can improve coral survival during heat stress. However, the biomolecular mechanisms underlying the algae's increased thermal tolerance have remained poorly understood. To address this gap, AIMS scientist Dr.
Bede Johnston conducted experiments at the National Sea Simulator (SeaSim) at AIMS before using the Infrared Microspectroscopy beamline at the Australian Synchrotron to generate biomolecular "fingerprints" of individual heat-evolved and wild-type algal cells. He completed the research as part of his Ph.D. at the University of Melbourne and through the Reef Restoration and Adaptation Program (RRAP). Australian Synchrotron beamline scientist Dr.
Annaleise Klein, a co-author of the study, collaborated on measurements of proteins, lipids, carbohydrates and other molecules in the algae. The team examined the two symbiont strains across three different environments: living inside corals, growing independently in culture and after being expelled from their hosts. "We wanted to understand how heat-evolved algae respond to heat stress in different environments, and whether living inside or outside their coral hosts influenced these responses," said Johnston.
The researchers found that wild-type algae exhibited changes in their biomolecular composition under elevated temperatures, while heat-evolved algae generally maintained more stable profiles. "We observed increases in carbohydrates and changes in protein-associated molecules in the wild-type algae, consistent with a cellular stress response. In contrast, the heat-evolved symbionts showed a much more subdued stress response to elevated temperatures," explained Johnston.
Extract — continue reading at the source.
