This post is part of the Science Tuesday feature series on the USDA blog. Check back each week as we showcase stories and news from the USDA's rich science and research portfolio.
By Avtar Handa, Purdue University
I don’t know about you, but I find it frustrating to go into the grocery store looking for fresh fruit only to find the selection has already started to shrivel. Shelf life can be a problem all across the United States for regions that need to ship in produce. And it’s an even bigger problem for countries in Southeast Asia and Africa that cannot afford controlled-environment storage.
Working with Autar Mattoo of the Agricultural Research Service, we found a way to extend the shelf life of tomatoes by about a week. By inserting a naturally occurring yeast gene into the tomato’s DNA, we can increase production of a compound that slows aging and delays microbial decay. With further research, I believe the results of our study, which was published in The Plant Journal, will transfer to most other fruits as well.
This study, which was funded by the National Institute of Food and Agriculture with additional support form the US-Israel Binational Agricultural Research and Development Fund and the Purdue Research Foundation, showed that fully ripe tomatoes from those plants lasted about eight days longer before showing signs of shriveling compared with plants that didn’t have the yeast gene. Decay and rot symptoms associated with fungi were delayed by about three days.
The yeast gene we interested into the tomato DNA increases the production of spermidine, an organic compound found in all living cells. While its functions aren’t fully understood, my previous work with Matoo showed that spermidine may enhance the nutritional and processing quality of tomatoes.
These findings could be used soon by tomato growers and possibly even other fruit growers. Now that we know the function of this gene, it’s also possible to use conventional breeding to achieve the same outcome using tomato cultivars that already have a high level of this gene’s expression.
Our future work will continue to look at how spermidine and other organic compounds control biological functions in fruits. If we can increase the quality of the fruit, we can extend the market time of the fruit, a valuable benefit for growers and consumer alike.
