TITLE:
Cellular Growth Dynamics Affects Allelopathic Activity in Coffee Cell Culture
AUTHORS:
Muchamad Imam Asrori, Shinjiro Ogita
KEYWORDS:
Allelopathic Activity, Coffea canephora, Callus, Growth Phase, Sandwich Method Bioassay
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.14 No.8,
August
17,
2023
ABSTRACT: Cellular growth dynamics and allelopathic activity
in coffee cell cultures were examined as follows: First, we compared
allelopathic activity of seven woody plant calli, Coffea canephora, Derris indica, Ficus carica L., Juniperus
conferta, Prunus persica, Punica granatum, and Sonneratia ovata, using a modified
“sandwich method bioassay” and found that coffee callus showed the strongest
growth inhibition to lettuce seedling nearly 90% of hypocotyl and 96% of root.
This coffee callus actively proliferated, with a 21-fold increase during five
weeks of subculture, with a growth curve comprising two typical phases: a lag
phase of 0 - 2 weeks of culture and an exponential phase of 3 - 5 weeks of
culture. Allelopathic activity varied depending on the growth phase of the
coffee callus. The strongest allelopathic activity was detected in 1 -
2-week-old callus showing nearly 100% inhibitory effect on lettuce seedling
growth. As the allelopathic activity of coffee calli is extremely high, beyond
the natural level in coffee leaves and green beans, we focused on analyzing the
allelopathic activity of its aqueous extracts using high-performance liquid
chromatography. Several prominent peaks, including two reference alkaloids,
theobromine and caffeine, which are known allelochemicals in coffee plants, and
three distinct unknown peaks were identified at 270 nm in coffee calli during
the lag phase (1 - 2 weeks of culture). The higher
value of the total phenolic content in the lag phase also suggested a key
biosynthetic pathway in relation to the allelopathic activity of coffee callus
will be activated in the lag phase.