Silencing AHP genes in tomato (Solanum lycopersicum) using CRISPR-CAS9

Tomato is an important nutrient for human health. There are many abiotic and biotic stress factors for tomato which has massive production all over the world. These stress factros effect yield, even in some cases cause death of plant. Drought stress which is one of these stress factors is becoming more important problem for agricultural production with rising global warming and climate change. The aim of this study to develop tolerant tomato against climate change which end up with drought conditions. The ABA which is an important member of abiotic stress response mechanisms, is an positive regulator for plant to adaptation these conditions. With this purpose, the genes, Solcy01g080540 (AHP1) and Solyc06g084410 (AHP2), are chosen whichs positive effects of repression of homologs are already proven in Arabidopsis thaliana. These genes knocked-out by using CRISPR/Cas9 genome editing technology in tomato. AHP genes act as positive regulator of sitokinin signaling. Because of the antagonistic relationship between cytokinin and ABA which is the important member of response to stress conditions, silencing these genes end up with increased ABA signaling and drought tolerance. Germination and drought stress assays have done after seed harvesting from genome edited plants. The results are compared with Crocker variety. The results demonstrated that ahp plants showed enhanced drought tolerance compared to Crocker. Moreover, it has seen that while Crocker plants are dying, ahp plants kept living. However, development of ahp plants decreased under no stress conditions. The ahp seeds which showed late germinatioon under normal conditions, are germinated under stress conditions while Crocker seeds could not germinated. As a result, the funtions of AHP genes in tomato have described, and drought tolerant variety is developed.