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Effects of Glyphosate-Based Herbicide on Primary Production and Physiological Fitness of the Macroalgae Ulva lactuca
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Orientador(es)
Resumo(s)
The use of glyphosate-based herbicides (GBHs) worldwide has increased exponentially over
the last two decades increasing the environmental risk to marine and coastal habitats. The present
study investigated the effects of GBHs at environmentally relevant concentrations (0, 10, 50, 100, 250,
and 500 µg·L
−1
) on the physiology and biochemistry (photosynthesis, pigment, and lipid composition,
antioxidative systems and energy balance) of Ulva lactuca, a cosmopolitan marine macroalgae species.
Although GBHs cause deleterious effects such as the inhibition of photosynthetic activity, particularly
at 250 µg·L
−1
, due to the impairment of the electron transport in the chloroplasts, these changes are
almost completely reverted at the highest concentration (500 µg·L
−1
). This could be related to the
induction of tolerance mechanisms at a certain threshold or tipping point. While no changes occurred
in the energy balance, an increase in the pigment antheraxanthin is observed jointly with an increase
in ascorbate peroxidase activity. These mechanisms might have contributed to protecting thylakoids
against excess radiation and the increase in reactive oxygen species, associated with stress conditions,
as no increase in lipid peroxidation products was observed. Furthermore, changes in the fatty acids
profile, usually attributed to the induction of plant stress response mechanisms, demonstrated the
high resilience of this macroalgae. Notably, the application of bio-optical tools in ecotoxicology, such
as pulse amplitude modulated (PAM) fluorometry and laser-induced fluorescence (LIF), allowed
separation of the control samples and those treated by GBHs in different concentrations with a high
degree of accuracy, with PAM more accurate in identifying the different treatments.
Descrição
Palavras-chave
Photobiology Energetic metabolism Pesticide Oxidative stress Glyphosate
Contexto Educativo
Citação
Cruz de Carvalho, R., Feijão, E., Matos, A. R., Cabrita, M. T., Utkin, A. B., Novais, S. C., Lemos, M. F. L., Caçador, I., Marques, J. C., Santos, P. R., Fonseca, V. & Duarte, B. (2022). Effects of Glyphosate-Based Herbicide on Primary Production and Physiological Fitness of the Macroalgae Ulva lactuca. Toxics, 10(8), 430. MDPI. http://dx.doi.org/10.3390/toxics10080430
Editora
MDPI