The fountain of youth – for tomatoes

Posted by Nicole Eckersley on 29th June 2010

Transgenic Handa tomatoResearchers at Purdue University have extended the shelf life of tomatoes by adding a gene from yeast, slowing aging and delaying microbial decay in tomatoes.

“We can inhibit the aging of plants and extend the shelf life of fruits by an additional week for tomatoes,” said professor of horticulture Avtar Handa. “This is basic fundamental knowledge that can be applied to other fruits.”

The genetically modified tomatoes lasted about eight days longer before showing signs of shriveling, compared to non-transgenic plants. Results also showed that ‘symptoms of decay and rot associated with fungi’ – that is, mould – were delayed by about three days.

“It increased the quality of the fruit,” Handa said. “If a tomato goes to market, people won’t buy it if it has started to shrivel. If we can stop that wrinkling, we can extend the market time of the fruit.”

Research collaborator and plant physiologist Autar Mattoo said the finding could have implications for areas that don’t often get fresh fruit.

“Shelf life is a major problem for any produce in the world, especially in countries such as in Southeast Asia and Africa that cannot afford controlled-environment storage,” he said.

Handa said tomato growers, and possibly other fruit growers, could use the findings soon, either through transgenic plants or natural breeding methods.

“We can add this gene to the tomatoes, or look at natural variation and select the cultivars that already have a high level of this gene’s expression,” Handa said.

The gene in question, a spermidine synthase gene, increases production of the organic compound spermidine, a polyamine found in all living cells. The function of polyamines is not fully understood, but previous research by Mattoo suggests that polyamines such as spermidine and spermine enhance the nutritional and processing quality of the tomato fruit.

“At least a few hundred genes are influenced by polyamines, maybe more,” Mattoo said. “We see that spermidine is important in reducing aging. It will be interesting to discover what other roles it can have.”