With the help of CRISPR/Cas molecular shears, genetic information in a plant can be modified to make the latter more resistant to pests, diseases or extreme climatic conditions. Researchers at the Karlsruhe Institute of Technology (KIT) have now further developed this method to eliminate the complete DNA of specific cell types and, thus, prevent their formation during plant development. It will also help scientists to better understand the development mechanism in plants. Presenting in conclusion nature communication,
Through molecular scissors, DNA – the carrier of genetic information – can be modified in plants. So far, the CRISPR/Cas method, co-developed in plants by Professor Holger Puchta, a molecular biologist at KIT’s Botanical Institute, has been used to specifically insert, exchange or combine genes. The goal is to increase the resistance of plants to diseases and environmental influences. CRISPR (stands for Clustered Regular Interspaced Short Palindromic Repeats)/Cas are molecular scissors that can specifically recognize and cut DNA sequences. “We have studied molecular scissors for plant use for 30 years now,” says Puchta. In the beginning, we applied them to modify individual genes. Two years ago, we were looking for complete chromosome rearrangements. was the first person in the world to For his research, the pioneer of genome editing has twice received advanced grants from the European Research Council (ERC). “We were able to optimize this method. With CRISPR-Kill, we have now reached an entirely new level of evolution: we can eliminate certain plant cell types and prevent the formation of specific plant organs. Huh.”
Eliminating Secondary Roots and Petals with CRISPR-Kill
The experiments conducted by the scientists focused on the secondary roots and petals of the model plant Thale cress (Arabidopsis thaliana). “These are classical examples in biology. Here, we know the genetic program and cell types that are important for the formation of these plant organs,” the molecular biologist explains. After elimination of these cells, CRISPR-killed plants no longer produced any petals or secondary roots, whereas control plants displayed normal growth.
Unlike other methods that eliminate cells with cytotoxins or laser irradiation, CRISPR-kill induces multiple cuts in the genome. A genome consists of a fixed number of chromosomes, on which individual genes are arranged in a definite order. “Until now, CRISPR/Cas has aimed for exactly one locus and cut once or twice when to modify a gene or chromosome,” Puchta says. “Now, we have reprogrammed our molecular scissors. They no longer address the genomic DNA just once, but target the relevant cell type to sequence that is frequently encountered in the genome and that is part of the cell. It’s necessary for survival. It takes, by the way, multiple cuts at the same time — cuts so long that the cell can’t heal them. The cell will die.”
Better understanding the developmental processes in plants
The work of KIT researchers can be classified as fundamental research. “By studying what happens when a certain type of cell ends, we learn more about the developmental processes in plants. How does the plant respond? How flexible is the plant during development? Can we learn more about those types of plants? Can remove parts that are not needed in agriculture, for example?,” says Puchta. In the long term, food production and pharmaceutical applications may benefit from this technology when the plant is prevented from producing cells that produce toxins, for example. Furthermore, the technology can be applied in multi-cellular organisms for specific modification of tissues.
material provided by Karlsruhe Institute of Technology (KIT), Note: Content can be edited for style and length.