In vitro propagation strategies of Puya chilensis as an alternative for obtaining new cysteine proteases

Puya chilensis is an endemic species of Chile belonging to the Bromeliaceae family, known for its morphological plasticity and ecological importance. In recent years, greater attention has been given to its conservation due to the indiscriminate use of its populations for food and medicinal purposes. In vitro culture is a tool for the propagation of plants species, as well as for obtaining bioactive compounds. In Chile, P. chilensis is the most representative within the Puya genus. This study focused on establishing an in vitro propagation protocol for P. chilensis that allows massive propagation and obtaining proteolytic enzymes. The combined effect of plants cuts and the application of 0.5 µmol L⁻¹ of BAP and GA₃ favored the in vitro multiplication of P. chilensis. Culture in liquid medium induced greater morphological development and early differentiation of anatomical structures in the leaves of P. chilensis in vitro. The use of TIS creates ideal conditions during the last stage of in vitro culture and ensures 100% survival during acclimatization phase. The management of cultivation conditions and the efficient use of TIS allowed the generation of P. chilensis plants with an optimal degree of development for obtaining proteolytic extracts. The main enzymes present in the extracts of P. chilensis plants grown in vitro belong to the cysteine type. This study proposes for the first time an optimized protocol for the propagation and conservation of P. chilensis, enhancing its uses as a source of biologically active molecules for the biotechnology and pharmaceutical industries.

Graphical Abstract