STUDY OF THE REGULATION AND CONTENT OF FLAVONOIDS DURING SEED DEVELOPMENT IN Sorghum bicolor

SEBASTIÁN P. RIUS; BERNACCHINI JOANA; RODRIGUEZ M.VICTORIA; CAMPAGNA NOEL; RODRIGUEZ M.VERÓNICA; CASATI PAULA

Rosario

Congreso; L Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular; 2014

For over a century, seed dormancy in cereals has been associated with red colour in different species. Therefore, the intermediate and final metabolites of the phenylpropanoid and flavonoid pathways not only affect seed coat colour, but they could also be associated to the sprouting phenotype in S. bicolor. In this work, the accumulation of phenolic compounds was analyzed during the development of the caryopsis in the seed coat of two sorghum lines with contrasting sprouting phenotypes (Redland B2, susceptible; and IS9530, resistant). The analysis of phenolic compounds by HPLC shows differences in the composition and concentration between the susceptible and the resistant lines at different developmental stages. Also, transcripts for flavonoid pathway enzymes (CHI, CHS, LAR and ANS), and a basic-HLH transcription factor (ZmIN1-like) were analyzed during grain maturation. Transcripts levels increased gradually in both lines during the development of the caryopsis but following different patterns. For example, the expression of b-HLH was detected between 15-20 days after pollination in the resistant line, while in the sensitive line it was only detected starting at 25-30 DAP. A regulating role of this b-HLH in the flavonoid pathway during the development of sorghum seed was also analyzed. These data provide insight into pigment accumulation of seed coat colour formation and its regulatory mechanisms in sorghum.