Cadmium Stress Signaling Pathways in Plants: Molecular Responses and Mechanisms.

Heavy metal (HM) pollution, specifically cadmium (Cd) contamination, is a worldwide concern for its consequences for plant health and ecosystem stability. This review sheds light on the intricate mechanisms underlying Cd toxicity in plants and the various strategies employed by these organisms to mitigate its adverse effects. From molecular responses to physiological adaptations, plants have evolved sophisticated defense mechanisms to counteract Cd stress.

The Role of Aquaporin Overexpression in the Modulation of Transcription of Heavy Metal Transporters under Cadmium Treatment in Poplar.

'Villafranca' clone is well-known for its tolerance to cadmium (Cd). To determine the mechanisms of Cd tolerance of this species, wild-type (wt) plants were compared with transgenic plants over-expressing an aquaporin (, GenBank GQ918138). Plants were maintained in hydroponic conditions with Hoagland's solution and treated with 10 µM of Cd, renewed every 5 d.

Histone acetylation recruits the SWR1 complex to regulate active DNA demethylation in .

Active DNA demethylation is critical for controlling the DNA methylomes in plants and mammals. However, little is known about how DNA demethylases are recruited to target loci, and the involvement of chromatin marks in this process. Here, we identify 2 components of the SWR1 chromatin-remodeling complex, PIE1 and ARP6, as required for ROS1-mediated DNA demethylation, and discover 2 SWR1-associated bromodomain-containing proteins, AtMBD9 and nuclear protein X1 (NPX1).

Characterization and quantification of thiol-peptides in Arabidopsis thaliana using combined dilution and high sensitivity HPLC-ESI-MS-MS.

Although thiol-peptide compounds, such as reduced glutathione (GSH), γ-glutamylcysteine (γ-EC), and phytochelatins, play fundamental roles in plants, their analytical determination and characterization is still somewhat problematic, mainly due to their high polarity and oxidation propensity. Thus, in this work a reliable and sensitive HPLC-ESI-MS-MS method was developed, in order to simultaneously assay, within 14-min instrumental runs, γ-EC, GSH, and phytochelatins up to phytochelatin 4. This analytical method was validated in shoot and root extracts of the model plant Arabidopsis thaliana (Brassicaceae) and guaranteed accurate quantification by using specific isotope labelled-internal standards for both GSH and phytochelatins, as well as standards for external calibration.

AQUA1 is a mercury sensitive poplar aquaporin regulated at transcriptional and post-translational levels by Zn stress.

Aquaporins are water channel proteins that regulate plant development, growth, and response to environmental stresses. Populus trichocarpa is one of the plants with the highest number of aquaporins in its genome, but only few of them have been characterized at the whole plant functional level. Here we analyzed a putative aquaporin gene, aqua1, a gene that encodes for a protein of 257 amino acid with the typical NPA (Asp-Pro-Ala) signature motif of the aquaporin gene family.

Removal of micro-pollutants from urban wastewater by constructed wetlands with Phragmites australis and Salix matsudana.

This study assessed the ability to remove micro-pollutants from wastewater using herbaceous species (Phragmites australis L.) and trees (Salix matsudana Koidz.) in constructed wetland (CW) systems.

The phytochelatin synthase from Nitella mucronata (Charophyta) plays a role in the homeostatic control of iron(II)/(III).

Although some charophytes (sister group to land plants) have been shown to synthesize phytochelatins (PCs) in response to cadmium (Cd), the functional characterization of their phytochelatin synthase (PCS) is still completely lacking. To investigate the metal response and the presence of PCS in charophytes, we focused on the species Nitella mucronata. A 40 kDa immunoreactive PCS band was revealed in mono-dimensional western blot by using a polyclonal antibody against Arabidopsis thaliana PCS1.

The Knockout Mutant for () Is Defective in Callose Deposition, Bacterial Pathogen Defense and Auxin Content, But Shows an Increased Stem Lignification.

The enzyme phytochelatin synthase (PCS) has long been studied with regard to its role in metal(loid) detoxification in several organisms, i.e., plants, yeasts, and nematodes.

Zolfino landrace (Phaseolus vulgaris L.) from Pratomagno: general and specific features of a functional food.

Background: The Zolfino bean is a variety of Phaseolus vulgaris, which is cultivated in a limited area of Tuscany, Italy, and is widely appreciated for its flavor and culinary uses.

Objectives: A yellow Zolfino landrace cultivated in the Leccio-Reggello area was characterized and compared with three other varieties of Phaseolus vulgaris (i.e.

Over-expression of AQUA1 in Populus alba Villafranca clone increases relative growth rate and water use efficiency, under Zn excess condition.

Transgenic Populus alba over-expressing a TIP aquaporin ( aqua1) showed a higher growth rate under Zn excess, suggesting that aqua1 could be involved in water homeostasis, rather than in Zn homeostasis. Populus is the internationally accepted model for physiological and developmental studies of tree traits under stress. In plants, aquaporins facilitate and regulate the diffusion of water, however, few poplar aquaporins have been characterized to date.

RNA sequencing of Populus x canadensis roots identifies key molecular mechanisms underlying physiological adaption to excess zinc.

Populus x canadensis clone I-214 exhibits a general indicator phenotype in response to excess Zn, and a higher metal uptake in roots than in shoots with a reduced translocation to aerial parts under hydroponic conditions. This physiological adaptation seems mainly regulated by roots, although the molecular mechanisms that underlie these processes are still poorly understood. Here, differential expression analysis using RNA-sequencing technology was used to identify the molecular mechanisms involved in the response to excess Zn in root.

Arsenic-induced morphogenic response in roots of arsenic hyperaccumulator fern Pteris vittata.

On the assumption that arsenic induces stress morphogenetic responses involved in As tolerance and hyperaccumulation in the Pteris vittata fern, we analyzed the root system of young sporophytes grown in 250, 334, and 500 μM As for five days and for 14 days. Anatomical and histological analyses were performed in plants grown for five days to evaluate the number, position, length and differentiation pattern of root hairs. AgNOR staining, employed to study nucleolus behavior in root apices, showed that arsenic influences nucleolar activity (evaluated by nucleolus size, number and absorbance) in the root meristem.

Transcriptome analyses of Populus x euramericana clone I-214 leaves exposed to excess zinc.

Zinc (Zn) is an essential element for plant growth and development, but at high levels this metal can become toxic. Hyperaccumulator species are often not suitable for phytoremediation technologies because they need to be fast growing and have high biomass production, such as those of the Populus genus. Comparative genomics studies of poplars subjected to stress conditions such as heavy metal contamination have generated resources useful for improving the annotation of genes and have provided novel insights in the defense/tolerance mechanisms governing adaptation in non-hyperaccumulator plants.

PRMT11: a new Arabidopsis MBD7 protein partner with arginine methyltransferase activity.

Plant methyl-DNA-binding proteins (MBDs), discovered by sequence homology to their animal counterparts, have not been well characterized at the physiological and functional levels. In order better to characterize the Arabidopsis AtMBD7 protein, unique in bearing three MBD domains, we used a yeast two-hybrid system to identify its partners. One of the interacting proteins we cloned is the Arabidopsis arginine methyltransferase 11 (AtPRMT11).

Mutations in a conserved replication protein suppress transcriptional gene silencing in a DNA-methylation-independent manner in Arabidopsis.

Mutations in the DNA glycosylase/lyase ROS1 cause transcriptional silencing of the linked RD29A-LUC and 35S-NPTII transgenes in Arabidopsis. We report here that mutations in the Arabidopsis RPA2 locus release the silencing of 35S-NPTII but not RD29A-LUC in the ros1 mutant background. The rpa2 mutation also leads to enhanced expression of some transposons.