Differential Activation of Defense Enzymes in Clonal Lines of Agave americana Derived from Chemical Mutagenesis in Response to Fusarium oxysporum Infection
Sugey Vásquez-Hernández, Joaquín Adolfo Montes-Molina*, Federico Antonio Gutierrez-Miceli, Nancy Ruiz-Lau, Victor Manuel Ruiz-Valdiviezo, Carlos Alberto Lecona-Guzmán*
Tecnológico Nacional de México, División de Estudios de Posgrado e Investigación, Instituto Tecnológico de Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Tuxtla Gutiérrez, Chiapas, México
* Corresponding Author: Joaquín Adolfo Montes-Molina. Email: 
; Carlos Alberto Lecona-Guzmán. Email: 
(This article belongs to the Special Issue: Advances in Ornamental Plants: Micropropagation, Plant Biotechnology, Chromosome Doubling, Mutagenesis, Plant Breeding, Environmental Stress Tolerance, and Postharvest Physiology)
Phyton-International Journal of Experimental Botany https://doi.org/10.32604/phyton.2026.076451
Received 21 November 2025; Accepted 18 February 2026; Published online 05 March 2026
Abstract
Agave americana L. is potentially a source of functional and nutritive compounds. However, its yield has been compromised by vascular wilt, which is associated with the presence of the
Fusarium oxysporum. In response to this phytosanitary problem, the implementation of efficient methods to mitigate the damage. Biotechnological techniques offer a viable alternative to improve and increase the production of species of interest via genetic improvement. By use of mutagenic chemical agents, these techniques have been consolidated as a powerful tool to induce genetic variability and select genotypes with greater tolerance to pathogens. In this study, we evaluated the activity of three pathogenesis-related (PR) enzymes, namely β-1,3-glucanase (PR2), chitinase (PR3), and peroxidase (PR9), that were present in second generation (F2) plants belonging to two resistant clonal lines and to one
A. americana line that was susceptible to
F. oxysporum. This was used to generate information that can be applied to biotechnology strategies for genetic preservation of the species and agro-industrial use. Plants that were six months old were selected, which were susceptible (Control) and resistant (Clone 1, Clone 4). These were inoculated with
F. oxysporum and kept under controlled greenhouse conditions. Enzyme activity was assessed at 0 and 72 hpi and then 7, 15, and 30 dpi. The results showed a significant decrease in β-1,3-glucanase enzyme activity in susceptible plants (control) and in clone 4, as compared to clone 1 plants. Regarding chitinase activity, a progressive increase was observed in control plants and clone 1 over time, while a steadier regulation was detected in clone 4. Lastly, peroxidase activity decreased over time in infected control plants, while dynamic variations were observed in both clonal lines, suggesting a regulated response. These findings indicate that enzyme activity plays a key role in defense against pathogens and that each clonal line of
A. americana could activate different defense mechanisms against infection by
F. oxysporum.
Keywords
Chemical mutagenesis; pathogenesis related proteins; resistance mechanisms; systemic acquired resistance
Open Access
Login
Register
Submit a Paper
Propose a Special lssue
Download PDF
Supplementary Material File
Downloads
Citation Tools
