Philippine E-Journals

Structures for Plant Defense in Young Leaves of Theobroma cacao

Glio Florgiley P. Arabejo | John Paul M. Banzon | Benito Anthony Pingoy | Maria Catherine B. Otero | Vivian S. Tolentino

Discipline: Biology, Research

 

Abstract:

Cacao (Theobroma cacao) is a popular crop in the tropical region that is used in the food, cosmeceutical, and pharmaceutical industries. But while cacao is widely studied for production, its morphological and anatomical features related to plant defenses have not been explored. Here we describe the special features of young cacao leaves used for plant defense using histological microtechniques. Permanent mounts of young cacao leaves were prepared after free-hand sectioning, tissue clearing, and rapid paraffin methods. Four types of trichomes, with varying distributions in the epidermis, were observed in the young cacao leaves: simple non-glandular trichome, short glandular trichome, tall/intermediate glandular trichome, and the sessile stellate non-glandular hair. Druse crystals and mucilaginous cells were also found in the epidermis. Knowing the defense structures in young cacao leaves provides bases for understanding its defense mechanisms. It also directs the investigations on the defensive phytochemicals, such terpenoids, alkaloids, anthocyanins, phenols, and quinines that are utilized in natural products research.