Updated project metadata. The development of seeds is a process of particular importance both for the plant itself – it assures the survival of the species, and for the human population – for nutritional and economic reasons. Controlling this process requires a strict coordination of many factors at different levels of cellular organization and complexity of regulatory mechanisms, the most important of which are gene transcriptional activity and hormonal homeostasis. In the control of seed filling processes, apart from specific regulatory proteins, the participation of phytohormones is also extremely important. The most important role is attributed to the interdependence between GA and ABA. In many plant species, phytohormones have been shown to affect the expression of genes related to the regulation of storage protein accumulation, especially ABSCISIC ACID INSENSITIVE3 (ABI3) and FUSCA3 (FUS3). The aim of the study was to verify whether exogenous application of phytohormones (ABA or GA) would significantly affect the amount of storage proteins accumulated in yellow lupin seeds.