Red anthocyanins contents and the relationships with phenylalanine ammonia lyase (PAL) activity, soluble sugar and chlorophyll contents in carmine radish (Raphanus sativus L.)

Red anthocyanins from Carmine radish is rich both in root flesh and peel and it is relatively simple and efficient to extract these compounds. The accumulation, distribution and content of anthocyanins in root are related to phenylalanine ammonia lyase (PAL) activity, soluble sugar and chlorophyll contents. The results showed that anthocyanins were synthesized at the first day of seed germination and were most abundant in the top of hypocotyls. The content of anthocyanins was higher in the root peel than in flesh and root apex, and in aboveground parts compared with underground sections. The anthocyanins contents in cotyledon grown under light and dark and hypocotyls grown in the dark increased initially and then reduced, and in roots grown under light was higher than in those grown in the dark. Chlorophyll content in leaves fluctuated but increased overall, whereas it was almost unchanged in the petioles. The correlations between anthocyanins content and PAL activity, soluble sugar and chlorophyll contents in different treatments showed positive by Day 4 then negative. These results are helpful to understand the mechanism of anthocyanins biosynthesis in carmine radish.