Clemens, S: Metal ligands in micronutrient acquisition and homeostasis, Plant Cell and Environment (2019), doi:10.1111/pce.13627 [Link]
Acquisition and homeostasis of micronutrients such as iron (Fe) and zinc (Zn) pose specific challenges. Poor solubility and high reactivity require controlled synthesis and supply of ligands to complex these metals extra‐ and intracellularly. Cytosolic labile pools represent only a minute fraction of the total cellular content. Several low molecular weight ligands are known in plants, including sulphur ligands (cysteine, peptides), nitrogen/oxygen ligands (S‐adenosylmethionine‐derived molecules, histidine) and oxygen ligands (phenolics, organic acids). Some ligands are secreted into the extracellular space and influence the phytoavailability of metal ions. A second principal function is the intracellular buffering of micronutrients as well as the facilitation of long‐distance transport in xylem and phloem. Furthermore, low molecular weight ligands are involved in the storage of metals, predominantly in vacuoles. A detailed molecular understanding is hampered by technical limitations, in particular the difficulty to detect and quantify cellular metal‐ligand complexes. More, but still too little, is known about ligand synthesis and the transport across membranes, either with or without a complexed metal. Metal ligands have an immediate impact on human well‐being. Engineering metal ligand synthesis and distribution in crops has tremendous potential to improve the nutritional quality of food and to tackle major human health risks.

last modified 2019-08-04