Characterization of Sunflower Leaf Senescence Process at Different Nitrogen Supplies in Two Contrasting Inbred Genotypes

SALVADOR NICOSIA; SOFIA BENGOA LUONI; MELANIE CORZO; AGUSTIN LOPEZ

Congreso; XXXIII Argentinian meeting of Plant Physiology (RAFV2021); 2021

Leaf senescence in plants is the last stage of leaf development, which is characterized by a decline in photosynthetic activity, an active degeneration of cellular structures and the recycling of accumulated nutrients to areas of active growth such as buds, young leaves, flowers, fruits and seeds. It is a process with economic impact since it can affect the yield due to the greater or lesser opportunity of the plants to maintain the active photosynthetic system during prolonged periods, especially during the stage of filling of grains affecting the weight and oil content of the plant. Leaf senescence is a complex mechanism controlled by multiple genetic and environmental variables. The visual symptoms of the leaves are detectable long after the activation of the signaling cascade of the process. The objective of this work aims to deepen the study of the leaf senescence process in sunflower in response to different nitrogen supplies using a broad overview approach of integration with physiological and phenotypical variable profiles. The field assay of two differential inbred lines previously selected from sunflower INTA Breeding Program bank were analyzed through different leaf developmental stages, in plants grown under different nitrogen supply at INTA Castelar. The results from this project will contribute to elucidate the metabolic pathways involved in the differential triggering and progression of the senescence process in sunflower, enabling the design of future comprehensive studies, allowing the detection of key nutritional biomarkers useful for genetic improvement of this oil crop of great importance for Argentine production.