Temperature Dependence and the Effects of Ultraviolet Radiation on the Ultrastructure and Photosynthetic Activity of Carpospores in Sub-Antarctic Red Alga Iridaea cordata (Turner) Bory 1826.

ABSTRACT: The short-term effects of UV radiation and low temperature on ultrastructure, photosynthetic activity (measured as the maximal photochemical quantum yield of photosystem II: F_v/F_m), chlorophyll-a (Chl-a) contents, and UV-absorbing compounds on the carpospores of Iridaea cordata from a sub-Antarctic population were investigated. Exposure to both photosynthetically active radiation (PAR) and PAR + UV for 4 h caused ultrastructural modifications in all treatments. Under PAR + UV at 2 °C, a disruption of the chloroplast's internal organization was observed. Plastoglobuli were often found in carpospores exposed to 2 °C. 'Electron dense particles', resembling physodes of brown algae, were detected for the first time in cells exposed to PAR and PAR + UV at 8 °C

SUBMITTER: Navarro NP 

PROVIDER: S-EPMC11435075 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature