Impacts of marine heatwaves on the red alga Gracilariopsis tenuifrons (Gracilariales, Rhodophyta): from acclimatation to thermal adaptation.

• Grant number: 23/15674-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): March 01, 2024
• Effective date (End): February 28, 2026
• Field of knowledge: Biological Sciences - Botany - Applied Botany
• Principal Investigator: Mariana Cabral de Oliveira
• Grantee: André Vinicius Fonseca de Faria
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Climatic extremes are becoming increasingly common amid a global warming trend. In the oceans, marine heatwaves (MHWs), discrete periods of abnormally warm water, have intensified and become more frequent over the last century, impacting the integrity of marine ecosystems. As sessile organisms, seaweeds may be more sensitive to MHWs than mobile organisms, exhibiting sharp declines after exposure to high temperatures. Therefore, studies on the influence of MHWs on marine seaweeds are essential to understand possible adaptations to thermal stress. The current project focuses on a species of red macroalga, Gracilariopsis tenuifrons, an agarophyte with economic importance and widely distributed along the Brazilian coast. To understand the mechanisms that this seaweed has to try to survive in a thermal stress, we will evaluate physiological parameters, such as growth, pigment content, photosynthesis, antioxidative responses, and molecular parameters, such as gene expression of transcripts, in two heatwave scenarios, 31°C and 33°C. We will also assess whether individuals have molecular plasticity to recover after thermal stress tests when grown at 28°C. For a better evaluation of the transcripts, we will sequence and assemble the haploid female nuclear genome of Gracilariopsis tenuifrons.