Determination of expression patterns of flavonoid biosynthetic genes in cultivars of Anthurium andraeanum towards understanding regulatory control of spathe colour.

Flavonoid and anthocyanin levels, and the expression profiles of four flavonoid biosynthetic genes were investigated in 16 anthurium cultivars with varying spathe colours with the objective of understanding the regulation of anthocyanin biosynthesis. The results suggested that F3H and ANS were controlled by a putative regulatory element designated 'R', DFR by another putative regulatory element designated 'O' and CHS by yet another mechanism. The differences between red and pink cultivars and orange and red cultivars were evident in both the anthocyanin and flavonoid levels as well as in the levels of expression of F3H and ANS controlled by the regulatory element 'R'. The higher level of expression of F3H in the red cultivars than in the pinks may be responsible for the different anthocyanins detected in the reds compared to the pinks. A plausible mechanism based on impediment of carbon flow down the flavonoid pathway is discussed. [ABSTRACT FROM AUTHOR]