SWEET CHERRY GENOME INITIATIVE
🍒 Strategic Genetic Engineering Program for Sweet Cherry in Chile
Chile is the only country in the Southern Hemisphere with a counter-seasonal supply of sweet cherry (Prunus avium L.), making it a key player in global markets. Sweet cherry plantations span from the Coquimbo to Aysén regions, representing nearly 5% of the total fruit-planted surface and contributing 1.7% of national fruit exports. The harvest season runs from November to January, with generally low yields averaging up to 5 tons/ha.
Despite the economic potential, conventional breeding programs in Chile have focused primarily on rootstock development, rather than on generating new productive cultivars through interspecific hybridization. To address this gap, the Biofrutales Consortium recently submitted a proposal to INNOVA titled “Programa Chileno para el Mejoramiento Genético del Cerezo”, aiming to establish a strategic national breeding initiative supported by the technical expertise of its member institutions.
🔬 Complementary Genetic Engineering Initiative
In parallel, our current proposal seeks to supplement the national breeding program by developing genetic engineering technologies for sweet cherry. Chile currently lacks transformation tools for P. avium, and this initiative aims to:
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Establish genetic transformation systems for sweet cherry.
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Enable candidate gene evaluation and gene expression control for both basic and applied breeding purposes.
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Introduce precise genomic modifications to confer desirable traits without compromising the commercial value of elite cultivars.
This approach offers a strategic advantage over conventional breeding programs abroad, allowing for targeted trait improvement while preserving cultivar identity.
🌿 Expanding Rosaceae Genomic Models
The development of transformation tools will also enable functional studies of homologous and interspecific genes within the Rosaceae family, positioning P. avium as a new woody model species for gene evaluation. This expands the limited set of Rosaceae models currently available for genomic research.
🧬 Breeding Targets and Long-Term Vision
The genetic engineering program is designed to integrate seamlessly with conventional breeding workflows, offering alternative solutions for:
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Monogenic traits: Resistance to pests, diseases, and cold stress.
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Multigenic traits (long-term): Improved post-harvest shelf life and optimized harvest timing.
In addition to applied outcomes, the platform will support basic knowledge acquisition and strengthen ongoing functional genomics efforts within Chile.
WHAT WE DO
Main goal:
To develop micropropagation and regeneration systems for the species (and close genotypes as rootstocks)
Specific Objectives:
•Regeneration protocols.
•Genetic transformation protocols.
•Vectors for genetic transformation.
•Evaluation of candidate genes in “model” varieties for the species.
Evaluation of an artificial miRNA from sweet cherry dormancy in a vernalization-dependent Arabidopsis
Flowering in sweet cherry is tightly linked to the rhythm of the seasons. As temperatures drop, cherry buds enter dormancy, a protective state that is only released after the tree accumulates enough winter chill. This transition is controlled by epigenetic shifts and precise gene regulation, including small RNAs that respond to environmental cues. By profiling dormant buds of the high-chill cultivar Regina, we identified miR396 as a key small RNA active during the dormancy cycle. To understand its function, we introduced an artificial sweet cherry version of miR396 into Arabidopsis Edi-0, a plant that normally requires vernalization to flower. The result was remarkable. Arabidopsis expressing the cherry miR396 flowered without any exposure to cold. The artificial miRNA reduced FLC, increased SVP and FT, and effectively bypassed the vernalization requirement. In other words, a dormancy-associated signal from sweet cherry was able to unlock flowering in a species that depends on winter chilling. This discovery reveals a new regulatory layer linking dormancy and flowering and opens the door to innovative strategies for controlling phenology in crops. Understanding how miR396 shapes seasonal transitions could help develop varieties that remain productive and resilient under changing climatic conditions.
