New insights into nutrient- and drought-responsive flowering

Nutrients not only provide energy and structural components but also play essential roles as regulatory molecules to control plant growth and development. Flowering is a key developmental phase transition (from vegetative to reproductive growth), and its precise timing determines reproductive fitness and crop yield. This requires coordination of metabolism, partitioning between source and sink tissues, and apical meristem activity with nutrient supplies. Here we summarize recent advances in our understanding of nutrient-regulated flowering, focusing on sugars and the three primary (soil-supplied) macronutrients nitrogen, phosphorus, and potassium, also considering drought stress as a highly relevant condition affecting nutrient availability. Most notably, recent evidence indicates that the evolutionarily conserved SNF1-RELATED KINASE 1 (SnRK1), a key metabolic sensor, serves as an integrator of nutrient status to control flowering. However, the combined effects of multiple nutrients on flowering and differences in responses between plant species remain underexplored and are an important topic for future research.