University of California, Davis, researchers have found that a processing tomato originally genetically engineered for higher solids about 20 years ago by Purdue University researchers also is less susceptible to blossom end rot.
Calcium deficiency is one of the main causes of blossom end rot, and the Purdue tomato allows more calcium to be mobile and available in tomato cells, according to a news release.
As its name implies, blossom end rot can cause dark, softened spots on the end of tomatoes.
At the time Purdue horticulture professor Avtar Handa developed the transgenic tomato, the market wasn't ready to accept the fruit so the work was dropped and the seeds stored away.
About two years ago, UC post-harvest pomologist Elizabeth Mitcham and former graduate student Sergio Tonnetto de Frietas, asked for some seeds.
They were particularly interested in Handa's earlier observations about how the transgenic tomatoes stored calcium.
What the UC Davis researchers found was non-engineered tomatoes produced high levels of an enzyme that binds to calcium and immobilizes it in the fruit.
The same strategy used to produce thicker solids silenced the enzyme production in the transgenic tomato, greatly reducing the binding sites for calcium within the cell walls.
This freed the calcium to be used by other parts of the tomato cells.
About 80 percent of wild-type tomatoes will suffer from blossom end rot under conducive conditions.
Under similar conditions, only about 30 percent of the Purdue transgenic tomatoes will develop the problem.
Mitcham plans to expand her work to look at the roles the enzyme and calcium play in calcium deficiencies apples, lettuce, peppers and watermelons.