L-histidine makes Ni 'visible' for plant signalling systems: Shading the light on Ni-induced Ca and redox signalling in plants.

Nickel is both an important nutrient and an ecotoxicant for plants. Organic ligands, such as L-histidine (His), play a key role in Ni detoxification. Here, we show that His (added together with 0.

The Role of Low-Molecular-Weight Organic Acids in Metal Homeostasis in Plants.

Low-molecular-weight organic acids (LMWOAs) are essential O-containing metal-binding ligands involved in maintaining metal homeostasis, various metabolic processes, and plant responses to biotic and abiotic stress. Malate, citrate, and oxalate play a crucial role in metal detoxification and transport throughout the plant. This review provides a comparative analysis of the accumulation of LMWOAs in excluders, which store metals mainly in roots, and hyperaccumulators, which accumulate metals mainly in shoots.

Nicotianamine: A Key Player in Metal Homeostasis and Hyperaccumulation in Plants.

Nicotianamine (NA) is a low-molecular-weight N-containing metal-binding ligand, whose accumulation in plant organs changes under metal deficiency or excess. Although NA biosynthesis can be induced in vivo by various metals, this non-proteinogenic amino acid is mainly involved in the detoxification and transport of iron, zinc, nickel, copper and manganese. This review summarizes the current knowledge on NA biosynthesis and its regulation, considers the mechanisms of NA secretion by plant roots, as well as the mechanisms of intracellular transport of NA and its complexes with metals, and its role in radial and long-distance metal transport.

Zinc- and nickel-induced changes in fatty acid profiles in the zinc hyperaccumulator Arabidopsis halleri and non-accumulator Arabidopsis lyrata.

This pilot study aimed at comparing zinc (Zn) and nickel (Ni) effects on the fatty acid (FA) profiles, oxidative stress and desaturase activity in the Zn hyperaccumulator Arabidopsis halleri and the excluder Arabidopsis lyrata to allow a better picture of the physiological mechanisms which may contribute to metal tolerance or acclimation. The most significant changes in the FA composition were observed in the shoots of the hyperaccumulator and in the roots of the excluder, and were not only metal-dependent, but also species-specific, since the most significant changes in the shoots of A. halleri were observed under Ni treatment, though Ni, in contrast to Zn, was accumulated mainly in its roots.

Phytochelatins: Sulfur-Containing Metal(loid)-Chelating Ligands in Plants.

Phytochelatins (PCs) are small cysteine-rich peptides capable of binding metal(loid)s via SH-groups. Although the biosynthesis of PCs can be induced in vivo by various metal(loid)s, PCs are mainly involved in the detoxification of cadmium and arsenic (III), as well as mercury, zinc, lead, and copper ions, which have high affinities for S-containing ligands. The present review provides a comprehensive account of the recent data on PC biosynthesis, structure, and role in metal(loid) transport and sequestration in the vacuoles of plant cells.