Exploring the relationship between plant secondary metabolites and macronutrient homeostasis

Nutrient content in the soil is considered one of the leading complications influencing plant growth and development. Plants sense the readily available nutrients in soil and uptake them to ensure growth and development. Based on the required amounts of nutritional elements, plant nutrients are classified into primary macronutrients, secondary macronutrients, and micronutrients. The nutrients are absorbed by roots and transported into various parts of the plant body by nutrient-specific transporters. On the other hand, plants produce various secondary metabolites that are not directly involved in growth and development but are mainly used for plant defense against various biotic and abiotic stressors. Recently, plant secondary metabolites have been reported to be affected by soil nutrients, which can influence soil nutrient cycling and increase the sustainability of agroecosystems. In this chapter, we focus on macronutrients while highlighting nutrient sensing, plant–soil interaction in terms of macronutrient uptake, and regulation of macronutrients in plant tissues (processes which include various factors that control nutrient homeostasis). In particular, we emphasize the significant contribution of plant secondary metabolites and their responses to soil fertility.