Saffron (Crocus sativus) develops new corms, or underground storage stems,
at the base of every shoot that grew from the maternal corm. Hence, the
number of corms that can be produced from the mother corm is influenced by
the number of bud sprouts from it. Strigolactones (SLs) are plant hormones
involved in suppression of axillary bud growth. Hence, it was investigated
to determine if SLs have any involvement in the corm productivity of
saffron. Two of the genes in the SL pathway, CCD7 and CCD8 were focused on
and evaluated. These genes encode enzymes required for the production of SL.

The CsCCD7 and CsCCD8 genes were quite similar, but were not identical.
CsCCD8 was highly expressed in dormant axillary buds and cutting the apical
bud dramatically reduced its expression suggesting its role in the
suppression of axillary bud growth from the corm. Furthermore, in vitro
experiments showed the involvement of auxin, cytokinin, and jasmonic acid on
the sprouting of axillary buds from corms where the apical bud was removed.
Results reveal that strigolactones suppress the outgrowth of the axillary
buds, similar to its suppression of the above-ground shoot branching.

[www.biomedcentral.com]