Functional characterization of the tomato sugar transporter SWEET10

Project Summary

Tomatoes are one of the most important fleshy fruit crops of modern agriculture. The sugary globe’s versatile nature has led it to become a staple in the dishes of countless cultures across the world. It is this sugar content that differentiates a refreshingly sweet tomato from an unpalatably bitter one. Although a new family of sucrose transporters called SWEETs has been recently discovered in Arabidopsis and rice, little is known of their actions with regards to sugar acquisition in fleshy fruits in general and tomato fruit in particular. Preliminary RNA-seq data has shown that SWEET10, a member of the SWEET family, is highly expressed during early tomato fruit development in the placenta. Due to this early insight, SWEET10 was selected as a suitable candidate for preliminary functional characterization. Comparison of fruit sugar content in wild-type plants and in transgenic RNAi plants in which SWEET10 expression is down-regulated revealed an altered sugar accumulation pattern in the SWEET10 RNAi lines. Using quantitative RT-PCR we showed that auxin regulates the expression of SWEET10 and some of its closest homologs, a finding which may shed light on its expression, and on the regulation of fruit sugar content during ripening.

Our results not only aim to characterize SWEET genes in tomato, but may also provide insight for breeders hoping to harness genetic information to restore the sweeter characteristics of tomatoes that were lost during domestication.

My Experience

My experiences in the Plant Genome Research Program at BTI will be tremendously helpful in my future scientific endeavors. Not only will the laboratory techniques and skills learned be of great assistance, but the very experience of having spent time at a world-class plant research institute will prove valuable. By observing other researchers collaborate between labs and even between institutes I have gained an understanding of the way science is accomplished. The program has also exposed me to the entire spectrum of plant biology research. Having been shown to such a wide array of the dynamic field of plant biology I feel as though I can make more informed decisions for graduate school and beyond. It is due to the aforementioned traits that my summer at BTI has impressed upon me lessons which will aid me at every step of my future.