Silencing of genes involved in fatty acid synthesis pathway in solanum lycopersicum using CRISPR/Cas9 system

Tomatoes (Solanum lycopersicum) are among the most consumed foodstuffs worldwide. Tomatoes, which have a rich content in terms of health, attract the attention of consumers. Many studies such as increasing the nutritional content of foodstuffs, extending the shelf life, increasing the resistance to biotic/abiotic stress factors are carried out by using various genome editing systems. Tomato, which is an important foodstuff both in health and economic terms, is used as a model organism for genome editing studies among dicot plants. In this study, it was aimed to silence the genes involved in the fatty acid synthesis pathway in the tomato plant with the CRISPR/Cas9 system and thus to determine the characterization of these genes in the tomato plant. Fatty acyl-ACP thioesterase B (FATB) and Palmitoyl-Acyl Carrier Protein Thioesterase genes play an important role in determining the chain length during fatty acid synthesis and in carbon flow between two lipid biosynthesis pathways in plants. The vector (pHSE401) carrying Cas9 and gRNAs for the mutation in the target genes was introduced into the plant by Agrobacterium tumefacience. When the leaves of the obtained mutant tomato plants were examined with electron microscopy, it was observed that the number of trichomes of the transgenic tomato developed decreased compared to the wild species. In the sections examined under the electron microscope, a decrease of 62.5% in plant 6, 66.7% in plant 8 and 70.8% in plant 11 were observed at 300 times magnification compared to wild type in the 9.7 mm leaf section of mutant plants. in addition, when the cuticle structure was also examined, it was observed that differentiation occurred on the upper surface of the cutin matrix in the form of structural disorders according to the wild type. Mutant plants were infected by Tuta absoluta, a tomato pest, and showed greater sensitivity compared to wild-type plants. Considering all these results, by looking at the results of mutations in the Fatty acyl-ACP thioesterase B (FATB) and Palmitoyl-Acyl Carrier Protein Thioesterase genes in the domatas plant, it was concluded that the plant is more sensitive under biotic stress conditions. Thanks to these differences, the tomato in question becomes more sensitive to biotic factors and therefore it is expected that it can be used as a model for the development of biotic stress-tolerant plants.