Narcissus and Daffodil

Production of galanthamine in vitro 217
Although de-differentiated callus was not the best system for alkaloid production,
it was interesting to observe that it had a biosynthetic capability, thus constituting a
useful experimental system for studying the biosynthesis of alkaloids because of its
simple structure.
Callus maintenance: alkaloids in meristematic tissue
After 6 months of maintaining callus in the same conditions, meristematic callus
from both strains A and B was transferred to an MS medium without auxins to
promote embryo maturation. Two months later, the callus derived from strain A
showed a high number of white globular structures which seemed to be cauline
tips, and even some somatic embryo-like protuberances were observed. The B
strain derived callus was more compact, and some of the protuberances were
elongated like the root meristem.
The alkaloid content was determined separately in callus from both A and B strains
when removing the auxins from the medium. As expected, from the chemical
point of view, the alkaloid profile was different in the two strains (Figure 7.1B),
according to their different morphological development. While the embryogenic
callus (strain A) accumulated mainly galanthamine-type alkaloids, N-formylnorgalanthamine
being the most abundant (58% of total alkaloids), those from strain B
(rhizogenic callus) contained haemanthamine as the major alkaloid (43.5% of total
alkaloids). Thus, the type of cellular organisation influences the qualitative profile
of alkaloids accumulated in the meristematic callus.
Callus regeneration: alkaloids in organogenic tissue
Callus from N. confusus has been found to maintain its regenerative capability for a
period of about two years if kept in a medium supplemented with 10 mg/l of 2,4-D
or picloram (Sellés, 1996). This organogenic capacity of the N. confusus callus is not
µg/g DW
120
100
80
60
40
20
0
NFNGAL GAL HAEM TAZ
Alkaloid
A strain B strain
A
µg/g DW
400
350
300
250
200
150
100
50
0
NFNGAL GAL HAEM TAZ
Alkaloid
A strain B strain
Figure 7.1 Alkaloid content in friable (A) and meristematic (B) callus from two strains
of seed-derived explants (values represent means of three replicates). NFN-
GAL, N-formylnorgalanthamine; GAL, galanthamine; HAEM, haemanthamine;
TAZ, tazettine.
B