? Copy nature to resist viruses

One of the effects of climate change is the spread of viruses in cultivated plants. One strategy to reduce the use of pesticides and promote the application of agroecological practices is to increase the natural resistance of plants to viruses. Promising results, imitation natural selection (In biology, natural selection is one of the mechanisms that guide evolution…) using genome editing techniques, appeared Jan. 30 in the Journal of Plant Biotechnology.

For millennia, cultivated plants have been shaped by domestication processes. Farmers are constantly cutting and selecting new varieties adapted to the changing environment. Although effective, this process takes time. In addition, the character sought must be somewhere within the diversity of the species to be improved.

Transferring the mechanism from one species to a species of agronomic interest becomes a new challenge. Among the available technologies, new methods for editing the genome of plants have been available since 2012. Often compared to molecular scissors, the CRISPR-Cas9 technique allows for targeted and precise modification of a region of DNA. plant (Plants (Plantae Haeckel, 1866) are multicellular organisms…).

Several cultivated species, including pepper or chickpea, are resistant to diseases caused by viruses of the potyvirus genus, for example.¹. How do they do it? Some viruses a protein (A protein is a biological macromolecule consisting of one or more…) of the plant to infect it. This protein a (Protein A is a 40-60 KDa surface protein…) in fact, it serves two functions: it is used by the virus and it also serves the function of the plant. Plants that are resistant to infection have acquired mutations he was ashamed (A gene is a sequence of deoxyribonucleic acid (DNA) and…) encoding this protein. These mutations make it impossible for the virus to use this protein during its lifetime functional (In mathematics, the term functional refers to certain functions…) for the plant. Thus, a plant with these mutations becomes resistant to infection and does not change anything for the plant!

A new study aimed to transfer this mechanism to crops of agronomic interest by studying the feasibility of tomato. cherry (Cherry is the edible fruit of the cherry tree. After strawberries, the most…). For this, the INRAE ​​teams used an approach different (In mathematics, the difference is defined in algebraic theory…) from classical methodology. They did not try to inactivate the gene that made the plant susceptible to the virus, but modified it to mimic the mutations responsible for the resistance found in peas or peppers.

To do this, they applied the CRISPR-Cas9 technique to target two regions of this gene. These simultaneous changes lead to changes in the protein produced by this gene. These changes give the plant strong resistance to several viruses of the potyvirus genus, including PVY. As with naturally selected mutations in other species, these changes do not alter the expression or assembly of the protein produced by the gene, nor do they affect its function.

This work is a proof-of-concept that offers a new approach for precise mutation editing aimed at enhancing natural resistance in susceptible species and thereby limiting pesticide use.

These results were obtained within the framework of the GENIUS project (2014-2020), supported by Plan Investissements d’Avenir. The aim of this project is to develop genome editing tools to contribute to plant improvement, including resistance to pathogens. Currently in progress potato (Potato or potatoes (colloquial, Canadian and regional French)…) As part of the European H2020 GENEBECON project (harnessing the potential of gene editing for a sustainable bioeconomy) aims to reduce contamination (Pollution is defined as making the environment unhealthy. Definition varies by…) and therefore climate change using genome editing.

Note:
¹ Potyviruses are the largest group RNA virus (An RNA virus is a virus that uses RNA as its genetic material, or else…) affects plants. It includes several economically important viruses, including Virus Y apple (An apple is the fruit of an apple tree, a widely cultivated fruit tree. The study of cultivation…) (PVY) poses a threat to a number of crops of agronomic interest, including potato, tobacco, tomato and pepper.

Reference:
(2023) An iterative gene editing strategy scales up eIF4E1 genetic diversity Solanum lycopersicum and produces resistance to multiple potyvirus isolates. Plant Biotechnol J.,
https://doi.org/10.1111/pbi.14003.