PMTFOS · Plant metallothioneins as potential players in food security

Plant metallothioneins as potential players in food security

It is estimated that over 2 billion people all over the word suffer from micronutrients deficiency (so called “hidden hunger”). Among several micronutrients, including iron, iodine, and copper, zinc is of particular importance because it is required not for one or a few specific functions, but is involved in almost all conceivable metabolic processes. Therefore, on the one hand zinc deficiency poses a serious threat to humans’ and animals’ life and health and on the other hand it severely impairs plant growth and crop yields. A long term and cost-effective strategy to overcome these issues is biofortification that is based on improved crop cultivars capable to accumulate more micronutrients in their edible parts. The other serious issue emerging in this context are toxic metals like cadmium. The chemical properties of zinc and cadmium are very similar and therefore most proteins involved in zinc uptake from soil and transport and storage within plants also bind toxic cadmium efficiently. Importantly, contamination of the soil with cadmium is not restricted to industrial and mining areas, but recently the amount of this toxic metal has increased also in agricultural land as a result of the usage of cadmium-rich phosphate fertilizers and sewage sludge. Hence, it is crucial to identify proteins not only able to bind zinc but also able to discriminate between essential and non-essential metals. Micronutrient homeostasis in living organisms is governed by complicated networks of countless proteins. Among them, there is a family of proteins called metallothioneins (MTs) that have been shown previously to fold in a metal-dependent fashion. It was proposed that this mechanism is responsible for folding-mediated metal-discrimination. The overall objective of the PMTFOS project was the comprehensive analysis of the whole family of metallothioneins in Sorghum bicolor. Sorghum is a remarkable crop currently widely cultivated in arid and semi-arid regions of the world due to its unusual drought and heat resistance. More frequent and more widespread drought incidence will likely lead to more global usage of this crop in the future. A cross-disciplinary approach from whole-organism studies to the level of individual proteins was exploited to determine the potential of sorghum metallothioneins for zinc/cadmium discrimination and further for biofortification purposes.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз