Why are breeder tomatoes pale?

Figure 1a from the paper showing uniform green tomato fruit and fruit with green-shoulders.

Ever wonder why tomatoes you buy in the store have a uniform red color?  A mutation in the transcription factor SIGLK2 has been bred into almost all the strains grown commercially.  In an article out today, Dr. Ann Powell and colleagues show that SIGLK2 controls chloroplast development in tomato fruit, and a functional SIGLK2 leads to dark green fruit with dark shoulders.  Increased chloroplast development leads to higher sugar levels in the fruit, and could affect taste (although they did not check that).  Next time you are planning one of the recipes from our recipe section (http://bmcdb.wordpress.com/science-food/) pick out tomatoes that have dark shoulders if you want ones that don’t carry the mutation.

http://www.sciencemag.org/content/336/6089/1711.full

http://news.sciencemag.org/sciencenow/2012/06/how-tomatoes-lost-their-taste.html

http://www.npr.org/blogs/thesalt/2012/06/28/155917345/how-the-taste-of-tomatoes-went-bad-and-kept-on-going?ft=3&f=2%2C3%2C5%2C7%2C10%2C13%2C35%2C39%2C46

http://www.nytimes.com/2012/06/29/science/flavor-is-the-price-of-tomatoes-scarlet-hue-geneticists-say.html?_r=1&hpw