Identification of metabolic pathways and candidate genes associated to early leaf senescence process in sunflower by integration of transcriptomic, metabolomic and phenotypic data

MOSCHEN, S.; NICOSIA, S.; MARINO, J.; RIVAROLA, M.; ALVAREZ, D.; DOSIO, G.A.A.; PANIEGO, N.; HEINZ, R.A.; FERNANDEZ, P.

Toulouse

Simposio; International symposium on sunflower and climate change; 2018

Leaf senescence is a complex mechanism controlled by multiple variables, either from genetic and environmental origin that strongly impacts on crop yield. Senescence process is the last stage in leaf development, characterized by decreasein photosynthetic activity, nutrients recycling and ultimately cell death.The main aim of this work was to evaluate the leaf senescence process in two contrasting sunflower genotypes for post-anthesissenescence. The early senescence genotype R453and the delayed senescence genotypeB481-6, previously selected from the INTA association mapping population, were evaluated using ecophysiological,transcriptomics and metabolomics analysis.Measurements of green leaf area, foliar fluorescence, chlorophyll content, radiation interception, photosynthesis and grain filling, showed differences in the triggering and progress of the senescence process, showing yield increase in delayed senescence genotype. Transcriptomic analysis using RNAseq, along with the integration of metabolic profiles, showed an early activation of not only metabolic process associated to protein, lipids and cell wall degradation but also nutrient recycling in the early senescence genotype. Furthermore, NAC MYB and WRKY transcription factors families, associated to leaf senescence in model species also showed high expression levels in the early senescence genotype.The identification of metabolic pathways and candidate genes associated to the senescence process, will help to elucidate the molecular mechanisms of leaf senescence development in sunflower and generate molecular tools to facilitate future interventions on it, useful for not only application of biotechnology tools but also in assisted breeding for a complex trait with high impact on crop yield.