CHLOROPHYLL DEGRADATION IN THE BRACT OF DRAGON FRUIT (HYLOCEREUS SPP.)
Loss of greenness in the bract due to chlorophyll (Chl) degradation is one of the symptoms of senescence in dragon fruit (Hylocereus spp.). Chl degradation enzyme activities (chlorophyllase Chlase, Mg-dechelatase MD, chlorophyll-degrading peroxidase Chl-POX and pheophytinase PPH), Chl derivatives (chlorophyllide a Chlide a, pheophorbide a Pheide a, pheophytin a Phein a and 132-hydroxychlorophyll OHChl a), and Chl content were assayed during storage at 25°C. Chl a content decreased with storage while Chl b content remained unchanged. Chlase activity increased after one day of storage and decreased thereafter. MD and PPH activity increased gradually for the first two days of storage while Chl-POX activity increased during the first five days of storage and then decreased. Chlide a, Pheide a and OHChl a were undetectable throughout storage, while Phein a increased during storage. The results indicate that MD and PPH may be involved in Chl degradation. Chl derivatives, particularly Pheina, were accumulated as intermediate products during Chl degradation.
Kammapana, L., Jitareerat, P., Wongs-Aree, C., Srilaong, V. and Yamuchi, N. (2015). CHLOROPHYLL DEGRADATION IN THE BRACT OF DRAGON FRUIT (HYLOCEREUS SPP.). Acta Hortic. 1088, 79-84
dragon fruit, chlorophyll degradation, chlorophyll derivatives, chlorophyll degradation enzymes