Use of temporary immersion systems for the micropropagation of Puya alpestris (Poepp.) Gay as a source to produce proteolytic enzymes: TEMPORARY IMMERSION MICROPROPAGATION PUYA ALPESTRIS PROTEOLYTIC ENZYMES

• Published in: In vitro cellular & developmental biology. Plant 2024, Vol.60 (6), p.880-890
• Main Authors: Cabrera, Inelvis Castro, Hernández, Karel Vives, Burgos, Luciano Sotomayor, de la Torre, Martha Hernández
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Cell Biology; Developmental Biology; Life Sciences; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Plant Sciences; Plant Tissue Culture
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1007/s11627-024-10471-8

In vitro cultivation allows the propagation of plant species, the conservation of germplasm, the modification of cellular processes, and the obtaining of bioactive compounds. The Bromeliaceae family is distinguished by accumulating high contents of proteases in its organs. In Chile, it presents a high degree of endemism. The Puya genus is one of the most abundant, with great ecological, systematic, evolutionary, and biogeographic interest. Puya alpestris inhabits stony, arid, and semi-humid areas, and has long floral maturation times and very slow growth. Propagation by seeds does not guarantee the survival of natural populations for exploitation. The study aimed to evaluate the effect of different in vitro micropropagation methods of Puya alpestris on the synthesis and secretion of cysteine proteases. Shoots were grown from seeds germinated in vitro in various growth systems, such as semi-solid medium (SSM), liquid medium (LM) and temporary immersion systems (TIS). The combined effect of cutting and application of 0.5 µM 6-benzyl amino purine (BAP) and gibberellic acid (GA 3 ) favored the in vitro multiplication of the species. The study revealed that the cultivation method and the growth time significantly influenced the growth and morphological development of P. alpestris plants. Plants grown in liquid medium for 45 d showed a significant increase in morphological variables such as plant length, number of leaves, number of roots, and total biomass, as well as a greater physiological response in absolute growth rate (AGR) and net assimilation rate (NAR). Proteolytic extracts from plants grown in SSM for 45 d showed greater proteolytic activity. The contents of proteases released into the medium were higher in the LM culture. However, when propagating plants in TIS, the values of specific proteolytic activity in the medium were higher. This study proposes for the first time a protocol for the propagation and conservation of P. alpestris and supports the use of TIS to acquire new cysteine proteases.