II Workshop Internacional de Ecofisiología Vegetal aplicada al estudio de la determinación del rendimiento y la calidad de los cultivos de granos,

MOSCHEN, S.; FERNANDEZ, P.; PANIEGO, N.; HOPP, H.E.; DOSIO, G.A.A.; HEINZ, R.A.

Mar del Plata

Workshop; II Workshop Internacional de Ecofisiología Vegetal aplicada al estudio de la determinación del rendimiento y la calidad de los cultivos de granos,; 2013

RAICES, FAUBA, UIB, INTA, SAFV

NAC transcription factors have been described as relevant players in the regulation and progress of leaf senescence in model plants. Senescence process is abruptly triggered in cultivated sunflower (Helianthus annuus L.), one of the most important sources of edible vegetable oil, resulting in seriously limited production. This species represents one of the largest and evolved families of plant species which has genetic and physiological specificities that cannot be readily extrapolated from the studies in model species like Arabidopsis, particularly in the case of agronomic important traits. The aim of this work was to evaluate the transcriptional profiles of candidate genes HeAn-ORE1, HeAn-EIN2 and miRNA164 in two sunflower leaves representatives of different developmental stages undergoing natural senescence in association with physiological parameters such as chlorophyll, total soluble sugars and nitrogen content, in order to assess the triggering time of different mechanisms along the onset and evolution of the senescence process in sunflower. HeAn-ORE1, HeAn-EIN2 and miRNA164 showed similar transcriptional patterns to those observed in Arabidopsis. HeAn-ORE1 was highly expressed before the appearance of the first physiological symptoms of senescence. Interestingly, HeAn-ORE1 showed an earlier up regulation in leaves of plants close to maturity compared to younger plants. Hence, these results suggest that HeAn-ORE1 transcription factor could play an important role as potential trigger of leaf senescence in sunflower, opening new possibilities to explore senescence manipulation in this strategic oil crop.