Calcium and calcium ionophore A23187 induce high-frequency somatic embryogenesis in cultured tissues of Coffea canephora P ex Fr.

High-frequency somatic embryogenesis was
achieved in Coffea canephora using calcium ionophore
A23187, which influences the influx of calcium into a
cell. With 100 μM calcium ionophore and 5 mM
calcium, 85% and 70% of cultures produced embryogenic
tissue, with 105±7 and 95±8 primary embryos from
each callus mass respectively. Medium supplemented
with 100 μM EGTA (calcium chelator) or 1 mM
verapamil (calcium channel blocker) significantly reduced
somatic embryogenesis. Calcium imaging studies
were done to determine the relationship between morphogenetic
response and the cellular calcium levels. The
calcium ionophore/calcium treatment was very effective
in driving cellular machinery toward embryogenesis. The
embryos were regenerated into plantlets when cultured onMS
medium supplemented with 5 mM calcium/100 μM calcium
ionophore A23187. Somatic embryogenesis-derived plants
were successfully transferred to soil and grown to maturity in
the field.