The sour taste of citrus fruit results from the extremely low pH of juice vesicle cell vacuoles. Here the authors provide genetic evidence that a vacuolar P-type ATPase, that is known to determine flower color in petunia via vacuolar acidification, is also responsible for extreme acidification in citrus.
- Pamela Strazzer
- Cornelis E. Spelt
- Francesca M. Quattrocchio