2 research outputs found
Cadmium Stress Responses in <i>Brassica juncea</i>: Hints from Proteomics and Metabolomics
Among heavy metal stressors, cadmium
(Cd) pollution is one leading
threat to the environment. In this view, research efforts have been
increasingly put forward to promote the individuation of phytoextractor
plants that are capable of accumulating and withstanding the toxic
metals, including Cd, in the aerial parts. We hereby adopted the hyperaccumulator <i>B. juncea</i> (Indian mustard) as a model to investigate plant
responses to Cd stress at low (25 μM) and high (100 μM)
doses. Analytical strategies included mass-spectrometry-based determination
of Cd and the assessment of its effect on the leaf proteome and metabolome.
Results were thus integrated with routine physiological data. Taken
together, physiology results highlighted the deregulation of photosynthesis
efficiency, ATP synthesis, reduced transpiration, and the impairment
of light-independent carbon fixation reactions. These results were
supported at the proteomics level by the observed Cd-dependent alteration
of photosystem components and the alteration of metabolic enzymes,
including ATP synthase subunits, carbonic anhydrase, and enzymes involved
in antioxidant responses (especially glutathione and phytochelatin
homeostasis) and the Calvin cycle. Metabolomics results confirmed
the alterations of energy-generating metabolic pathways, sulfur-compound
metabolism (GSH and PCs), and Calvin cycle. Besides, metabolomics
results highlighted the up-regulation of phosphoglycolate, a byproduct
of the photorespiration metabolism. This was suggestive of the likely
increased photorespiration rate as a means to cope with Cd-induced
unbalance in stomatal conductance and deregulation of CO<sub>2</sub> homeostasis, which would, in turn, promote CO<sub>2</sub> depletion
and O<sub>2</sub> (and thus oxidative stress) accumulation under prolonged
photosynthesis in the leaves from plants exposed to high doses of
CdCl<sub>2</sub>. Overall, it emerges that Cd-stressed <i>B.
juncea</i> might rely on photorespiration, an adaptation that
would prevent the over-reduction of the photosynthetic electron transport
chain and photoinhibition
Cadmium Stress Responses in <i>Brassica juncea</i>: Hints from Proteomics and Metabolomics
Among heavy metal stressors, cadmium
(Cd) pollution is one leading
threat to the environment. In this view, research efforts have been
increasingly put forward to promote the individuation of phytoextractor
plants that are capable of accumulating and withstanding the toxic
metals, including Cd, in the aerial parts. We hereby adopted the hyperaccumulator <i>B. juncea</i> (Indian mustard) as a model to investigate plant
responses to Cd stress at low (25 μM) and high (100 μM)
doses. Analytical strategies included mass-spectrometry-based determination
of Cd and the assessment of its effect on the leaf proteome and metabolome.
Results were thus integrated with routine physiological data. Taken
together, physiology results highlighted the deregulation of photosynthesis
efficiency, ATP synthesis, reduced transpiration, and the impairment
of light-independent carbon fixation reactions. These results were
supported at the proteomics level by the observed Cd-dependent alteration
of photosystem components and the alteration of metabolic enzymes,
including ATP synthase subunits, carbonic anhydrase, and enzymes involved
in antioxidant responses (especially glutathione and phytochelatin
homeostasis) and the Calvin cycle. Metabolomics results confirmed
the alterations of energy-generating metabolic pathways, sulfur-compound
metabolism (GSH and PCs), and Calvin cycle. Besides, metabolomics
results highlighted the up-regulation of phosphoglycolate, a byproduct
of the photorespiration metabolism. This was suggestive of the likely
increased photorespiration rate as a means to cope with Cd-induced
unbalance in stomatal conductance and deregulation of CO<sub>2</sub> homeostasis, which would, in turn, promote CO<sub>2</sub> depletion
and O<sub>2</sub> (and thus oxidative stress) accumulation under prolonged
photosynthesis in the leaves from plants exposed to high doses of
CdCl<sub>2</sub>. Overall, it emerges that Cd-stressed <i>B.
juncea</i> might rely on photorespiration, an adaptation that
would prevent the over-reduction of the photosynthetic electron transport
chain and photoinhibition