Season and shading affect emetine and cephalin production in Carapichea ipecacuanha plants

Abstract

Ipecacuanha [Carapichea ipecacuanha) (Brot) L. Andersson] has a high commercial value due to the presence of emetine and cephalin in its roots, which can be enhanced by different levels of light intensity. This study aimed to study the physiological response of ipecacuanha plants under different shading levels (50, 70, and 90%) in all seasons. Plants were cultivated in a greenhouse with sombrite® (shading) for 395 days, in beds containing sandy soil, after which we evaluated chlorophyll (Chl) a fluorescence, photosynthetic pigments and emetine and cephalin. Chl a fluorescence was higher in plants under 50% shading in all seasons while plants under 90% shading showed increases in Chl a fluorescence in the summer. The changes in Chl a fluorescence under 50% shading reveal difficulties in adaptation to high light levels, since high light intensity causes disorders in the dynamic dissipation of photosynthetic energy, and a decrease in photosynthetic pigments. The highest content of cephalin was recorded in winter under 70% shading, whereas for emetine it was recorded in spring, under 90% shading. Autumn (70% shading) was the only season in which the amount of both emetine and cephalin was similar. Therefore, both the season and the shading level affect ipecacuanha metabolism.