Energy strategies of brown algae Lessonia spicata (Surh) Santelices (Phaeophyceae, Laminariales) to counter excess solar irradiance in the intertidal zone

Description

This dataset contains the physiological, biochemical, and molecular measurements obtained from the intertidal brown macroalga Lessonia spicata exposed to simulated seasonal irradiance regimes under controlled laboratory conditions. The experiment evaluated short-term acclimation responses to different combinations of photosynthetically active radiation (PAR) and ultraviolet radiation (UVA + UVB), representing seasonal light conditions (autumn, winter, spring, and summer) typical of the central Chilean coast. The dataset is organized into three sheets: Physiological responses: chlorophyll a fluorescence parameters derived from PAM fluorometry, including photosynthetic efficiency (αETR), maximum electron transport rate (ETRmax), saturation irradiance (Ek), maximum quantum yield of PSII (Fv/Fm), and maximum non-photochemical quenching (NPQmax). Biochemical responses: pigment concentrations (chlorophyll a), phenolic compounds, and oxidative stress indicators including hydrogen peroxide (H₂O₂) and lipid peroxidation (TBARS/MDA). Molecular responses: raw quantitative PCR values associated with genes involved in photosynthesis, pigment biosynthesis, electron transport and stress response. Samples were obtained from adult sporophytes of Lessonia spicata collected in the intertidal zone of central Chile and analyzed after exposure to controlled irradiance treatments. Measurements were conducted during a daily cycle at multiple sampling times to capture short-term physiological and transcriptional responses.

Steps to reproduce

Sample collection Adult sporophytes of Lessonia spicata were collected from the intertidal zone at Cochoa Beach, Montemar Marine Protected Area (Valparaíso, Chile). Individuals were selected based on similar size and morphology. Samples were transported to the Aquatic Coastal Environmental Research Laboratory (LACER) and maintained for 48 h in a common tank under controlled conditions (15 °C, 12:12 h light:dark photoperiod, ~50 µmol photons m⁻² s⁻¹ PAR) with aerated filtered seawater. After acclimation, algal fronds were randomly assigned to four seasonal irradiance treatments simulating natural conditions: PAB-Autumn, PAB-Winter, PAB-Spring, and PAB-Summer. Each treatment included PAR + UVA + UVB radiation using fluorescent and UV lamps, while temperature was maintained constant at 15 °C. Physiological measurements Photosynthetic performance was measured using a pulse-amplitude modulated fluorometer (Junior-PAM). Parameters obtained included maximum quantum yield (Fv/Fm), photosynthetic efficiency (αETR), maximum electron transport rate (ETRmax), saturation irradiance (Ek), and non-photochemical quenching (NPQmax). Biochemical analyses Tissue samples were collected at different times of the daily cycle and flash-frozen in liquid nitrogen. Pigments (chlorophyll a and c), phenolic compounds, hydrogen peroxide (H₂O₂), and lipid peroxidation (TBARS/MDA) were quantified using spectrophotometric assays. Molecular analyses Total RNA was extracted from frozen tissue samples, converted to cDNA, and gene expression was quantified using RT-qPCR. Target genes included photosystem components, pigment biosynthesis genes, and stress-response genes. Expression levels were normalized using 18S rRNA as the reference gene. Data organization The dataset is provided in three sheets corresponding to physiological, biochemical, and molecular responses under the four seasonal irradiance treatments.

Institutions

• Universidad de Playa Ancha de Ciencias de la Educación

  Valparaíso, Valparaíso
• Universidad de Buenos Aires

  Buenos Aires F.D., Buenos Aires

Categories

Funders

• FONDECYT 11180197, ANID, Chile.

  Grant ID: 11180197

Licence