Diseño metodológico de mutaciones dirigidas mediante el sistema crispr/cas9 para aumentar el período de dormancia en la papa criolla Solanum tuberosum grupo Phureja (variedad criolla Colombia) irradiada con 60CO

Abstract

In Colombia, for many decades, round potatoes from this diploid group, with yellow skin and flesh color, which are commonly known as “papa criolla” (phenotype “egg yolk”), were widely spread for cultivation and consumption. Its vegetative period is 120 days under the conditions of the surface of Bogotá (2600 meters above sea level), a short period compared to that of cultivated tetraploid potatoes (year-old potatoes), which have a period greater than 165 days. The Creole potato has great acceptance within the Colombian population, as well as in the international market. It is recognized for its special organoleptic qualities that allow it to be part of the preparation of multiple dishes in traditional cuisine, as well as its higher nutritional quality compared to the annual potato. The Creole potato presents short periods of post-harvest dormancy as a major problem, due to this it does not meet the conditions of prolonged storage and distribution, leading to the loss of its organoleptic and nutritional properties, reducing its possibility of national and international marketing. This process is influenced by some phytohormones, one of them is ethylene, described in the Yang cycle, in this metabolic route the synthesis of ethylene is under the strict control of the 1-aminocyclopropane-1-carboxylate oxidase (ACO) enzyme, which under the study of Expression levels of ACO homologous genes determine the rate of ethylene production in different plant tissues. During this process, in the Molecular Biology hotbed of the Francisco José de Caldas District University through financing from the International Atomic Energy Organization (FAO) have carried out research generating mutations through gamma rays of 60Co in the Creole potato Solanum Tuberosum (Phureja Group), which involves the controlled exposure of 60Co in a concentration of (25 - 100 Gy) so that it does not affect dietary health in the irradiated tubers. This ionizing radiation has enough energy to interact with the DNA of the cells, which can cause breaks in the DNA strands. The selected mutants underwent a study of the expression levels of the genes involved in ethylene synthesis to confirm the characteristics mutated and their stability through generations. Including field tests, genetic analyzes and comparisons with the non-irradiated Colombia variety. In this case, the selected clones (48, 33, 39, Col, Mut) characterized by their higher yield and presenting a slight increase in their dormancy periods will be the plant material that will be used in the research. Conventional breeding of Solanum Tuberosum (Phureja Group) is a process that takes many years; This time could be reduced through the implementation and use of molecular biology tools that accelerate variety selection processes and strengthen conventional genetic improvement programs (Pinto et al., 2010). Editing a genome is producing changes/mutations at specific, targeted, permanent and heritable sites in the genome of a species. This editing is mediated by DNA repair systems in the cell with the lowest probability of making errors (off-targets) and without leaving foreign DNA sequences (New England Biolabs, 2007). By modifying the genetic information of an organism, specific genes are introduced or eliminated, altering their function, for example, inactivating the ACO gene in the ethylene metabolic pathway, generating less ethylene production.