Understanding plant nutrition for a sustainable agriculture

Nowadays a worrying requirement of food haunts the scientific community: crop production must double to keep pace with growth in the global population, which will reach 9 billion people by the year 2050. Additionally, a decrease in available arable land has been estimated, therefore the plant science community should provide solutions to maintain and increase food production. Plants represent an important food source for both humans and animals. Plant production strongly depends on the availability of mineral nutrients. Macronutrients (i.e. nitrogen, phosphate, potassium, sulphate) and micronutrients (i.e. iron, copper, zinc) are essential for various aspects of plant growth and development. To cope with nutrient limitations, plants have developed a set of physiological and morphological responses to match resource availability with growth requirements. Such responses are regulated by a complex sensing and signaling mechanism that allows plants to monitor the external and internal concentration of mineral nutrients. Understanding such mechanisms represent a major issue in plant physiology and crop production, with potential impact on the design of new biofortification strategies for improving yields as well as the nutritional value of crops. Nutrient sensing and signalling in plants involves both local and systemic pathways. When a variation in the nutrient availability is perceived by the cell, specific signal molecules induce a transcriptional reprogramming mechanism at the nucleus level. At the tissue level, roots are expected to play the initial role in sensing the local mineral nutrient status of the soil. Through a long-distance signalling pathway, nutrient stress signals reach all plant organs, inducing the plant adaptation mechanisms. Here, the current knowledge about the nutrient sensing and signalling mechanisms related to some elements will be presented.