title: Effects of cadmium metal on young gametophytes of Gelidium floridanum: metabolic and morphological changes.
abstract: By evaluating carotenoid content, photosynthetic pigments and changes in cellular morphology, growth rates, and photosynthetic performance, this study aimed to determine the effect of cadmium (Cd) on the development of young gametophytes of Gelidium floridanum. Plants were exposed to 7.5 and 15 μM of Cd for 7 days. Control plants showed increased formation of new filamentous thallus, increased growth rates, presence of starch grains in the cortical and subcortical cells, protein content distributed regularly throughout the cell periphery, and intense autofluorescence of chloroplasts. On the other hand, plants treated with Cd at concentrations of 7.5 and 15 μM showed few formations of new thallus with totally depigmented regions, resulting in decreased growth rates. Plants exposed to 7.5 μM Cd demonstrated alterations in the cell wall and an increase in starch grains in the cortical and subcortical cells, while plants exposed to 15 μM Cd showed changes in medullary cells with no organized distribution of protein content. The autofluorescence and structure of chloroplasts decreased, forming a thin layer on the periphery of cells. Cadmium also affected plant metabolism, as visualized by a decrease in photosynthetic pigments, in particular, phycoerythrin and phycocyanin contents, and an increase in carotenoids. This result agrees with decreased photosynthetic performance and chronic photoinhibition observed after treatment with Cd, as measured by the decrease in electron transport rate. Based on these results, it was concluded that exposure to Cd affects cell metabolism and results in significant toxicity to young gametophytes of G. floridanum.
authors: Plant Cell Biology Laboratory, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, 88049-900, CP 476, Florianópolis, SC, Brazil, carmensimioni@hotmail.com.
authors: Carmen
authors: C
authors: Simioni
authors: Éder C
authors: ÉC
authors: Schmidt
authors: Ticiane
authors: T
authors: Rover
authors: Rodrigo
authors: R
authors: dos Santos
authors: Elisa P
authors: EP
authors: Filipin
authors: Debora T
authors: DT
authors: Pereira
authors: Giulia Burle
authors: GB
authors: Costa
authors: Eva Regina
authors: ER
authors: Oliveira
authors: Fungyi
authors: F
authors: Chow
authors: Fernanda
authors: F
authors: Ramlov
authors: Luciane
authors: L
authors: Ouriques
authors: Marcelo
authors: M
authors: Maraschin
authors: Zenilda L
authors: ZL
authors: Bouzon
mesh_terms: D002104:Cadmium / Q000633:toxicity*; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D004579:Electron Transport; D055993:Germ Cells, Plant / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D010788:Photosynthesis; D000461:Rhodophyta / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium; D002734:Chlorophyll; D002338:Carotenoids