Development of tomatoes with high sugar and GABA accumulation and parthenocarpic traits by introducing mutations in HWS and GAD3.

Tomatoes are vital crops globally and they provide numerous nutritional benefits, including vitamins, lycopene, and gamma-aminobutyric acid (GABA). This study utilized CRISPR/Cas9 technology to introduce mutations in two genes, HWS (Hawaiian Skirt) and GAD3 (glutamate decarboxylase 3), to enhance tomato quality, increase yield stability, and improve parthenocarpic traits. Our results demonstrated that HWS and GAD3 mutations led to higher sugar (Brix) and GABA content, as well as the induction of facultative parthenocarpy, especially at elevated temperatures. Moreover, facultative parthenocarpy in these mutants was attributed to the defective ability of the transcriptome to be fine-tuned by HWS, which caused more dynamic changes in phytohormone-related fruit development. These findings suggest that genetic modification can improve tomato quality and climate resilience.