Structure, ultrastructure and ontegenetic development of glandular trichomes of Smallanthus sonchifolius (Asteraceae), «yacón»

Abstract

Mercado, María I.; María V. Coll Araoz; Ana I. Ruiz; Alfredo Grau; Graciela I. Ponessa. 2012. “Structure, ultrastructure and ontegenetic development of glandular tri- chomes of Smallanthus sonchifolius (Asteraceae), «yacón»”. Lilloa 49 (1). Anatomical and ultrastructural changes occurring in glandular trichomes (GT) during leaf development and during the annual growth cycle of the Andean crop Smallanthus sonchifolius (Poepp. & Endl.) H. Rob. «yacón», were studied using a combination of light and electron microscopy. GT are fully established and their secretory activity appears to be concluded at early stages of leaf development. GT secretion is mainly constituted by sesquiterpene lactones, partly responsible for the antidiabetic activity of leaves, that are accumulated underneath the cuticle and released only when GT are mechanically disrupted. This study contributes to the understanding of «yacón» leaves chemical defenses and to improve harvesting techniques aiming at its pharmacological use.