All one needs from fruits is their special taste. I very much like cherries of Germany in this season aAs  they are proper mix of sweet and sour which gives a special taste.
What regulates their special taste .
It could be enzymatic reactions or malic enzyme activity or some other enzymes of sucrose biosynthesis but how does nature perceive the signal to maintain particular taste.
They shout in the market "Deutsche eardbearen"( please correct me if I spelled it wrong)
among Italian , Spanian, or other countries. Deutsche eardbearen fetch more price and are sweeter. French wine is famous world over. There are special vellies which make best wines in Germany or for that matter in USA .
Do the plants recognise the countries and behave differently .( They dont need visa to travel or show their passports) However they dont change their places either. Plants specific to Germany wont have same taste if grown in Spain or vice versa.
Olive are famous from Spain. Oranges are famous from some of the mediterranean countries.
I have always wondered what makes plants to switch particular enzyme  biosynthesis, its degradation or its expression, enzyme kinetics,  tranlastional or transcriptional control or metabolomics in its totality. What role is played by soil micro and macro nutrients or complex interaction of nutrient uptake and transport or partitioning of photsynthates or the pH regulation of cytosol or apoplast. In final terms its all game of pH or some factors which I dont know.
It takes wine tasters to make good wine but plants dont have any sweet tasters yet I have not eaten better cherries except from this season in Giessen of Germany at this time of year.
Environmental regulation of sweetness or particular taste could be the answer in all its complexity.
Should we not protect our environment to protect taste of our fruits and keep sweetness of life intact.
Sweet cherries of Frankfurt Germany