Generation of parthenocarpic tomato plants in multiple elite cultivars using the CRISPR/Cas9 system

Abstract

Tomato (Solanum lycopersicum L.) is one of the most important crops in the world for its fruit production. Many critical characteristics related to the quality and quantity of tomatoes have been developed using cutting-edge techniques. Recently, genetic techniques such as gene transformation and gene editing have emerged as powerful tools to promptly generate new plant varieties with superior traits. In this study, we successfully induced parthenocarpy traits in a population of elite tomato (ET) lines. The ET lines were screened for their adaptability to new genetic techniques to determine the lines that performed best by applying ANT1 gene transformation and IAA9 knock-out using the CRISPR/Cas9 system. ET5 and ET8 emerged as excellent materials for these techniques due to their high efficiency in applying those modern techniques. Phenotypes of knock-out iaa9 were clearly shown in T-0 and T-1 plants, in which simple leaves and parthenocarpic fruits were observed. We generated T-DNA-free homozygous iaa9 knock-out plants in the T-1 generation, indicating the high efficiency of CRISPR/Cas9 in developing new varieties with desired traits in the shortest time possible. Additionally, a simple artificial fertilization method was successfully applied to recover seed production from parthenocarpy plants, securing the varieties for use as breeding materials.