Transfer of alkaloids from Delphinium to Castilleja via root parasitism. Norditerpenoid alkaloid analysis by electrospray mass spectrometry
Norditerpenoid alkaloids which are present in the roots of Delphinium occidentale are assimilated into its root parasite, Castilleja sulphurea. The alkaloids are found in all plant parts of the Castilleja (roots, stems, leaves, flowers, seeds) and in the flower nectar. The major root alkaloids (browniine, delcosine, deltaline and dictyocarpine; analyzed by positive ion electrospray mass spectrometry, ESMSH+) were transmitted into the Castilleja. Little or none of the highly mammalian toxic alkaloids (such as methyllycaconitine) were found in D. occidentale. ESMSH+ also was used to identify alkaloids of D. barbeyi, where browniine, delcosine and a small amount of methyllycaconitine (roots only) were found. ESMSH+ provided a useful method for analysis of norditerpenoid alkaloids. Their presence as assimilates in a root parasite plant could provide a defense against herbivory.