Zn is an essential element for life and the second most abundant transition element in all organisms. Zn deficiency is one of most widespread micronutrient deficiencies in soils and plants need to cope with it. Plants are able to sense the shortage of Zn supply and adjust their Zn homeostasis accordingly. I have used forward and reverse genetics approaches to learn more about the genetic architecture of Zn homeostasis, especially under Zn deficiency conditions, in the model species Arabidopsis thaliana. The results obtained in this thesis contributes to our understanding of the complexity of the Zn deficiency response, which bring us one step further in improving the Zn content of plant products and the Zn deficiency tolerance of crops.