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Temporal aspects of copper homeostasis and its crosstalk with hormones.

Peñarrubia L, Romero P, Carrió-Seguí A, Andrés-Bordería A, Moreno J, Sanz A - Front Plant Sci (2015)

Bottom Line: Spatial and temporal processes that can be affected by hormones include the regulation of copper uptake into roots, intracellular trafficking and compartmentalization, and long-distance transport to developing vegetative and reproductive tissues.In turn, hormone biosynthesis and signaling are also influenced by copper availability, which suggests reciprocal regulation subjected to temporal control by the central oscillator of the circadian clock.This transcriptional regulatory network, coordinates environmental and hormonal signaling with developmental pathways to allow enhanced micronutrient acquisition efficiency.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Plant Molecular Biology, Department of Biochemistry and Molecular Biology, University of Valencia, Valencia Spain.

ABSTRACT
To cope with the dual nature of copper as being essential and toxic for cells, plants temporarily adapt the expression of copper homeostasis components to assure its delivery to cuproproteins while avoiding the interference of potential oxidative damage derived from both copper uptake and photosynthetic reactions during light hours. The circadian clock participates in the temporal organization of coordination of plant nutrition adapting metabolic responses to the daily oscillations. This timely control improves plant fitness and reproduction and holds biotechnological potential to drive increased crop yields. Hormonal pathways, including those of abscisic acid, gibberellins, ethylene, auxins, and jasmonates are also under direct clock and light control, both in mono and dicotyledons. In this review, we focus on copper transport in Arabidopsis thaliana and Oryza sativa and the presumable role of hormones in metal homeostasis matching nutrient availability to growth requirements and preventing metal toxicity. The presence of putative hormone-dependent regulatory elements in the promoters of copper transporters genes suggests hormonal regulation to match special copper requirements during plant development. Spatial and temporal processes that can be affected by hormones include the regulation of copper uptake into roots, intracellular trafficking and compartmentalization, and long-distance transport to developing vegetative and reproductive tissues. In turn, hormone biosynthesis and signaling are also influenced by copper availability, which suggests reciprocal regulation subjected to temporal control by the central oscillator of the circadian clock. This transcriptional regulatory network, coordinates environmental and hormonal signaling with developmental pathways to allow enhanced micronutrient acquisition efficiency.

No MeSH data available.


Related in: MedlinePlus

Overview of Arabidopsis thaliana cellular Cu homeostasis. Cu+ uptake through plasma membrane transporters COPT1/COPT2/COPT6 depends on the activity of AHA H+-ATPase and FRO cuproreductases. COPT-mediated Cu+ transport is coupled to metallochaperones transfer and its delivery to targets. Cuprochaperone CCS provides Cu+ to cytosolic superoxide dismutase CSD1. ATX1 transfers Cu+ to P-type ATPase RAN1, located at the ER, where Cu+ is probably acquired by cuproproteins, such as multicopper oxidases (MCOs), the ethylene receptor (ETR1), and the molybdenum cofactor (MoCo). The Cu resulting from recycling and from the secretory pathway leftovers converges into the vacuole or into vacuolar-related organelles (VROs). The Cu+ supply to chloroplasts and mitochondria can take place from the lumen through the COPT5 efflux function. See the main text for details. The direction of Cu+ traffic is indicated by arrows and Cu content is indicated by different intensities of blue.
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Figure 1: Overview of Arabidopsis thaliana cellular Cu homeostasis. Cu+ uptake through plasma membrane transporters COPT1/COPT2/COPT6 depends on the activity of AHA H+-ATPase and FRO cuproreductases. COPT-mediated Cu+ transport is coupled to metallochaperones transfer and its delivery to targets. Cuprochaperone CCS provides Cu+ to cytosolic superoxide dismutase CSD1. ATX1 transfers Cu+ to P-type ATPase RAN1, located at the ER, where Cu+ is probably acquired by cuproproteins, such as multicopper oxidases (MCOs), the ethylene receptor (ETR1), and the molybdenum cofactor (MoCo). The Cu resulting from recycling and from the secretory pathway leftovers converges into the vacuole or into vacuolar-related organelles (VROs). The Cu+ supply to chloroplasts and mitochondria can take place from the lumen through the COPT5 efflux function. See the main text for details. The direction of Cu+ traffic is indicated by arrows and Cu content is indicated by different intensities of blue.

Mentions: Under aerobic conditions, Cu2+ is the most abundant form of copper in soil solution and probably enters plant root cells through divalent cation low-affinity transporters, such as some members of the ZIP family (ZIP2 and ZIP4; Wintz et al., 2003). However, this still has to be proven in vivo. Under metal deficiencies, plants acidify the external medium by using H+-ATPases (AHA; Santi and Schmidt, 2009). When Cu is scarce, plants use a Cu+-specific transport system based on Cu2+ reduction by plasma membrane NADPH-dependent cupric reductases FRO4 and FRO5 (Bernal et al., 2012) and on cytosolic uptake by high-affinity CTR-like transporters, denoted COPTs in plants (Sancenón et al., 2003; Figure 1). COPT substrate availability depends on both free external Cu (not bound to inorganic and organic complexes) and the Cu+/Cu2+ ratio according to external redox status conditions and the enzymatic activity of cuprooxidoreductases. The energetically expensive reductive strategy used for Cu+ uptake has been shown to be the predominant and ubiquitous mechanism for Cu acquisition in dicotyledons (Jouvin et al., 2012; Ryan et al., 2013). This redox strategy in Cu+ uptake could be an adaptation possibly required for specific high-affinity monovalent cation selection or/and for meeting specific Cu+ intracellular needs.


Temporal aspects of copper homeostasis and its crosstalk with hormones.

Peñarrubia L, Romero P, Carrió-Seguí A, Andrés-Bordería A, Moreno J, Sanz A - Front Plant Sci (2015)

Overview of Arabidopsis thaliana cellular Cu homeostasis. Cu+ uptake through plasma membrane transporters COPT1/COPT2/COPT6 depends on the activity of AHA H+-ATPase and FRO cuproreductases. COPT-mediated Cu+ transport is coupled to metallochaperones transfer and its delivery to targets. Cuprochaperone CCS provides Cu+ to cytosolic superoxide dismutase CSD1. ATX1 transfers Cu+ to P-type ATPase RAN1, located at the ER, where Cu+ is probably acquired by cuproproteins, such as multicopper oxidases (MCOs), the ethylene receptor (ETR1), and the molybdenum cofactor (MoCo). The Cu resulting from recycling and from the secretory pathway leftovers converges into the vacuole or into vacuolar-related organelles (VROs). The Cu+ supply to chloroplasts and mitochondria can take place from the lumen through the COPT5 efflux function. See the main text for details. The direction of Cu+ traffic is indicated by arrows and Cu content is indicated by different intensities of blue.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400860&req=5

Figure 1: Overview of Arabidopsis thaliana cellular Cu homeostasis. Cu+ uptake through plasma membrane transporters COPT1/COPT2/COPT6 depends on the activity of AHA H+-ATPase and FRO cuproreductases. COPT-mediated Cu+ transport is coupled to metallochaperones transfer and its delivery to targets. Cuprochaperone CCS provides Cu+ to cytosolic superoxide dismutase CSD1. ATX1 transfers Cu+ to P-type ATPase RAN1, located at the ER, where Cu+ is probably acquired by cuproproteins, such as multicopper oxidases (MCOs), the ethylene receptor (ETR1), and the molybdenum cofactor (MoCo). The Cu resulting from recycling and from the secretory pathway leftovers converges into the vacuole or into vacuolar-related organelles (VROs). The Cu+ supply to chloroplasts and mitochondria can take place from the lumen through the COPT5 efflux function. See the main text for details. The direction of Cu+ traffic is indicated by arrows and Cu content is indicated by different intensities of blue.
Mentions: Under aerobic conditions, Cu2+ is the most abundant form of copper in soil solution and probably enters plant root cells through divalent cation low-affinity transporters, such as some members of the ZIP family (ZIP2 and ZIP4; Wintz et al., 2003). However, this still has to be proven in vivo. Under metal deficiencies, plants acidify the external medium by using H+-ATPases (AHA; Santi and Schmidt, 2009). When Cu is scarce, plants use a Cu+-specific transport system based on Cu2+ reduction by plasma membrane NADPH-dependent cupric reductases FRO4 and FRO5 (Bernal et al., 2012) and on cytosolic uptake by high-affinity CTR-like transporters, denoted COPTs in plants (Sancenón et al., 2003; Figure 1). COPT substrate availability depends on both free external Cu (not bound to inorganic and organic complexes) and the Cu+/Cu2+ ratio according to external redox status conditions and the enzymatic activity of cuprooxidoreductases. The energetically expensive reductive strategy used for Cu+ uptake has been shown to be the predominant and ubiquitous mechanism for Cu acquisition in dicotyledons (Jouvin et al., 2012; Ryan et al., 2013). This redox strategy in Cu+ uptake could be an adaptation possibly required for specific high-affinity monovalent cation selection or/and for meeting specific Cu+ intracellular needs.

Bottom Line: Spatial and temporal processes that can be affected by hormones include the regulation of copper uptake into roots, intracellular trafficking and compartmentalization, and long-distance transport to developing vegetative and reproductive tissues.In turn, hormone biosynthesis and signaling are also influenced by copper availability, which suggests reciprocal regulation subjected to temporal control by the central oscillator of the circadian clock.This transcriptional regulatory network, coordinates environmental and hormonal signaling with developmental pathways to allow enhanced micronutrient acquisition efficiency.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Plant Molecular Biology, Department of Biochemistry and Molecular Biology, University of Valencia, Valencia Spain.

ABSTRACT
To cope with the dual nature of copper as being essential and toxic for cells, plants temporarily adapt the expression of copper homeostasis components to assure its delivery to cuproproteins while avoiding the interference of potential oxidative damage derived from both copper uptake and photosynthetic reactions during light hours. The circadian clock participates in the temporal organization of coordination of plant nutrition adapting metabolic responses to the daily oscillations. This timely control improves plant fitness and reproduction and holds biotechnological potential to drive increased crop yields. Hormonal pathways, including those of abscisic acid, gibberellins, ethylene, auxins, and jasmonates are also under direct clock and light control, both in mono and dicotyledons. In this review, we focus on copper transport in Arabidopsis thaliana and Oryza sativa and the presumable role of hormones in metal homeostasis matching nutrient availability to growth requirements and preventing metal toxicity. The presence of putative hormone-dependent regulatory elements in the promoters of copper transporters genes suggests hormonal regulation to match special copper requirements during plant development. Spatial and temporal processes that can be affected by hormones include the regulation of copper uptake into roots, intracellular trafficking and compartmentalization, and long-distance transport to developing vegetative and reproductive tissues. In turn, hormone biosynthesis and signaling are also influenced by copper availability, which suggests reciprocal regulation subjected to temporal control by the central oscillator of the circadian clock. This transcriptional regulatory network, coordinates environmental and hormonal signaling with developmental pathways to allow enhanced micronutrient acquisition efficiency.

No MeSH data available.


Related in: MedlinePlus