Scientists unravel the genetic secrets of a pink tomato

Jan 14, 2010

Far Eastern diners are partial to a variety of sweet, pink-skinned tomato. Dr. Asaph Aharoni of the Weizmann Institute's Plant Sciences Department has now revealed the gene that's responsible for producing these pink tomatoes. Aharoni's research focuses on plants' thin, protective outer layers, called cuticles, which are mainly composed of fatty, wax-like substances. In the familiar red tomato, this layer also contains large amounts of antioxidants called flavonoids that are the tomatoes' first line of defense. Some of these flavonoids also give the tomato cuticles a bright yellow cast - the color component that is missing in the translucent pink skins of the mutants.

Using a lab system that's unique in Israel, and one of only a few in the world, Aharoni and his team are able to rapidly and efficiently identify hundreds of active plant substances called metabolites. A multidisciplinary approach developed over the past decade, known as metabolomics, enables them to create a comprehensive profile of all these substances in mutant plants and compare it with that of normal ones.

The research, carried out in Aharoni's lab by Dr. Avital Adato, Dr. Ilana Rogachev and research student Tali Mendel, showed that the differences between pink and red tomatoes go much deeper than : The scientists identified about 400 genes whose activity levels are quite a bit higher or lower in the mutant . The largest changes, appearing in both the plant cuticle and the fruit covering, were in the production of substances in the flavonoid family. The pink tomato also has less lycopene, a red pigment known to be a strong antioxidant that's been shown to be associated with reduced risk of cancer, heart disease and diabetes. In addition, alterations in the fatty composition of the pink tomato's outer layer caused its cuticle to be both thinner and less flexible that a regular tomato skin.

The researchers found that all of these changes can be traced to a mutation on a single gene known as SIMYB12. This gene acts as a 'master switch' that regulates the activities of a whole network of other genes, controlling the amounts of yellow pigments as well as a host of other substances in the tomato. Aharoni: 'Since identifying the gene, we found we could use it as a marker to predict the future color of the fruit in the very early stages of development, even before the plant has flowered. This ability could accelerate efforts to develop new, exotic tomato varieties, a process that can generally take over 10 years.'

Explore further: How does enzymatic pretreatment affect the nanostructure and reaction space of lignocellulosic biomass?

add to favorites email to friend print save as pdf

Related Stories

Unique tomatoes tops in disease-fighting antioxidants

Feb 27, 2007

Deep red tomatoes get their rich color from lycopene, a disease-fighting antioxidant. A new study, however, suggests that a special variety of orange-colored tomatoes provide a different form of lycopene, one that our bodies ...

Tomatoes found to fight sun damage

Apr 28, 2008

Tomatoes could be the new weapon in the fight against sun damage to the skin, research at the Universities of Newcastle and Manchester has revealed. According to a study presented at the British Society for Investigative ...

Tomato stands firm in face of fungus

May 09, 2008

Scientists at the University of Amsterdam have discovered how to keep one’s tomatoes from wilting – the answer lies at the molecular level. The story of how the plant beat the pathogen, and what it means for combating ...

Tomato vaccines: New bird flu weapon?

Mar 15, 2006

Australian scientist Amanda Walmsley says she is trying to grow a bird flu vaccine in tomatoes to be used to prevent the disease in chickens.

A dash of salt grows healthier tomatoes

Apr 28, 2008

Watering tomatoes with diluted seawater can boost their content of disease-fighting antioxidants and may lead to healthier salads, appetizers, and other tomato-based foods, scientists in Italy report. Their ...

Recommended for you

The origin of the language of life

11 hours ago

The genetic code is the universal language of life. It describes how information is encoded in the genetic material and is the same for all organisms from simple bacteria to animals to humans. However, the ...

Quest to unravel mysteries of our gene network

Dec 18, 2014

There are roughly 27,000 genes in the human body, all but a relative few of them connected through an intricate and complex network that plays a dominant role in shaping our physiological structure and functions.

EU court clears stem cell patenting

Dec 18, 2014

A human egg used to produce stem cells but unable to develop into a viable embryo can be patented, the European Court of Justice ruled on Thursday.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.