Genetically Improved Fruits for Greater Resilience

Genetically Improved Fruits for Greater Resilience

CIIDIR Sinaloa scientist enhances fruit resistance to water stress and climate change through genetic modification, impacting leaf and fruit size as well as pathogen response

Nestor Pinacho

Water stress and climate change are now harsh realities significantly affecting agricultural production worldwide. In response to this complex situation, Dr. Lucina Romero Romero, a scientist at the Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional (CIIDIR), Unidad Sinaloa, is conducting cutting-edge research to develop fruits more resistant to adverse conditions through genetic modification.

After completing her doctoral studies at the Pontificia Universidad Católica de Chile, Dr. Romero identified the need to strengthen fruit production in Sinaloa. While grains, legumes, and vegetables have been long cultivated, they have faced commercialization and cultivation issues. “Fruit cultivation could provide an opportunity to reinforce established production lines and offer alternative options to producers in Sinaloa and across the country,” she noted.

Given climate change, the alternative food source represented by the polyploidization of fruits—specifically blueberries, oranges, and mandarins, which served as the basis for her research—is key to creating more resilient organisms.

“A polyploid organism has an increased chromosome set. By increasing plant ploidy to 4x, 5x, or 6x, this elevation makes them more robust, akin to creating a ‘Hulk’ version; with more chromosomal content, they become stronger to face biotic and abiotic stress.” These modifications impact the density and number of stomata, leaf and fruit size, increased resistance to water stress, and pathogen attack.

Stomata, Dr. Romero explained, are pores primarily located on the underside of leaves. These structures, composed of two guard cells, are where plants lose approximately 98 percent of the water absorbed during the day through transpiration.

Since these modified plants have fewer stomata on their stems and leaves, the amount of water they lose during the day is reduced, lowering their water demand. This allows them to tolerate more limited irrigation and survive with less water.

“Radiation or high temperatures naturally cause plants to duplicate genetic materials; we replicate this in the lab using chemical agents that induce these mitotic failures, resulting in plants with duplicated or increased genetic material,” she explained.

MODIFICATION PROCESS

The modification process begins with blueberries from other countries with low chill hour requirements, as there is no native diversity of this species in Mexico. Using varieties whose patents have expired, germplasm banks are established in vitro, and small micro-cuttings and seeds are exposed to mitosis inhibitors, such as colchicine or oryzalin, to inhibit the process.

Next, organogenesis protocols are established to generate new shoots from treated seeds or micro-cuttings in vitro. This procedure produces new shoots and subsequently completes plants. Once their root systems develop, they are acclimatized in a substrate and biochemical, physiological, and genetic analyses are conducted to verify the success of the process.

INTERNATIONALIZATION

Dr. Romero emphasized that studying abroad provided a solid foundation for her research. “I decided to do something different and useful, aiming for national presence and a broader vision that would position our center and the Politécnico on a global stage.”

She highlighted the contributions of Dr. Patricio Arce Johnson as a valuable collaborator and mentor to the master's and doctoral students working with her. These students are undertaking internships in Chile, as collaboration should extend beyond national borders.

Currently, the research is in the process of demonstrating results, Dr. Romero said, including validating water stress tolerance and determining nutritional content. The goal is to ensure these plants can withstand Sinaloa’s climatic conditions and analyze them from physiological, biochemical, and metabolic perspectives to present results to producers.

ECONOMIC BENEFITS

In Mexico, producers pay around 0.3 to 0.7 dollars for genetically improved plants developed by foreign producers. Chile and the United States are the leading developers of these fruits globally, earning significant income from this. “If we succeed in developing our varieties for Mexico, adapted to our climatic conditions, we would not only improve our plants but also retain the royalty within the country with a Mexican seal,” Dr. Romero concluded.

Selección Gaceta Politécnica #175. (June 30th, 2024). IPN Imagen Institucional: Read the full magazine in Spanish here.