Ten years after the publication that reported the invention of CRISPR/Cas "molecular scissors", CREA (Centro di ricerca Olivicoltura Frutticoltura Agrumicoltura in Acireale) publishes its first article on an international journal (Salonia et al., 2022) using Assisted Evolution Technologies to improve the quality of citrus fruits.
AETs maintain the genetic background unaltered, only modifying characters that make a variety imperfect and simulating what would happen in nature or through traditional genetic improvement. These however would take years, extensive resources and large spaces. AETs instead make it possible to achieve the same objectives in less time thus saving money, although a lot of work is needed anyway to identify the genes to modify and the perfect regeneration protocols, which are variety-dependent.
The study published used genome editing to "switch off" the beta-cyclase gene (responsible for converting lycopene into beta-carotene) so that lycopene (a metabolite that conveys the classic pink color to Star Rubi and Navel Cara Cara grapefruits, but also the same compound found in tomatoes) can be produced and accumulated also in orange varieties with anthocyanins. It is a known fact that anthocyanins are anti-oxidant and anti-cancer agents that help prevent and cure many diseases, so why not imagine even healthier fruits?
The CITRUS project financed by MIPAAF (2018-2023) as part of the BIOTECH project guided by Concetta Licciardello, First Researcher at CREA in Acireale, enabled the development of constructs and the regeneration of citrus fruit varieties considered "recalcitrant". It also trained new generations of researchers who have already produced edited plants of various types of pigmented varieties, including blood and Tarocco ones.
"We just need to wait for plants to produce fruits and verify in the vases and in the fields (hoping that the law changes) what we have assessed in the lab. Technically, it is anyway already possible to say that genome editing worked. AETs represent an ever-evolving innovative biotechnological approach that has the objective or protecting and promoting Italian varieties while improving the aspects demanded by the market, consumers and climate change."
"Before this study, AETs were applied to citrus fruit to add resistance to bacterial canker in susceptible species such as 'Duncan' grapefruits and 'Valencia' oranges. Italy was the first to apply 'molecular scissors' to improve the quality of citrus fruits. The knowledge acquired places researchers in an advantageous situation, as they can now take advantage of their skills to obtain plants resistant to harmful organisms thus contributing to solving current and future phytosanitary emergencies. Let us remember, in fact, that Huanglongbing and bacterial canker are at the doorstep of the Mediterranean and currently there is no cure nor any sources of resistance among the varieties grown."
Concetta Licciardello, PhD
Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria
Centro di ricerca Olivicoltura Frutticoltura Agrumicoltura
Corso Savoia 190, 95024
Acireale (Catania) Italy