Thermal stress impairs photophysiology and redox balance in the kelp <i>Lessonia spicata</i>.

ABSTRACT: Warming oceans are reshaping coastal ecosystems, yet the thermal sensitivity of many foundation macroalgae remains poorly constrained. Under SSP2-4.5, sea surface temperatures are expected to rise by ~2.7 °C by 2100, with unknown consequences for the canopy-forming kelp Lessonia spicata. We exposed thalli to control (15 °C) and warming (18 °C) conditions for 14 days to simulate near-future thermal scenarios, assessing photophysiology, oxidative stress and pigment composition. Warming caused marked declines in F_v/F_m and ETR_max and increased NPQ_max, signaling reduced photochemical efficiency and enhanced thermal energy dissipation. Simultaneously, pigment concentrations decreased, ROS and MDA accumulated, and antioxidant capacity dropped, indicatin

SUBMITTER: Navarrete C 

PROVIDER: S-EPMC12745468 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature