Ectopic expression of apple MdSUT2 gene influences development and abiotic stress resistance in tomato

- Ectopic expression of MdSUT2 promotes the accumulation of soluble sugar in tomato.
- Overexpression of MdSUT2 significantly improved tolerance to low temperature, drought and salt stress.
- The ectopic expression of MdSUT2 resulted in early flowering and fruit-ripening in tomato.

Sucrose transporters are crucial factor in carbon partitioning and in response to environmental stresses. They coordinate sucrose transport with plant growth and development. In this study, an apple sucrose transporter gene MdSUT2 was ectopically transformed into tomato. Transgenic tomato lines were used for functional characterization. Soluble sugar content was increased in transgenic tomato lines. Esculin uptake assay indicated sucrose transport activity was improved in the roots of transgenic tomato lines. Meanwhile, the MdSUT2 transgenic lines accumulated more anthocyanin in leaves when grew under low temperature conditions than the WT control, and noticeably enhanced tolerance to drought and salt stresses. The ectopic expression of MdSUT2 resulted in early flowering and fruit-ripening in the transgenic tomatoes. These findings provide evidence for the role of sucrose transporters in promoting fruit ripening and resistance to abiotic stresses.