He studies the molecular and biochemical mechanisms by which plants resist and accumulate heavy metals. Plants and seeds are the main source of essential metals – zinc, iron, magnesium and copper – and also the main entry point into the food chain for toxic elements such as cadmium, lead, arsenic and mercury. Mendoza is working to identify and characterize the transporters responsible for the long-distance movement in plants of heavy metals, both the essential and the toxic. Understanding these mechanisms will help to enhance the nutritional value and safety of plant based products. This knowledge could also be useful for improving current techniques for phytoremediation, which is the use of plants to clean up toxic compounds, particularly at sites contaminated with heavy metals.