Adding a yeast gene to tomatoes increased production of a compound that slows aging and delays microbial decay, researchers at Purdue University reported. High levels of the polyamine spermidine increased the shelf life of tomatoes and may do the same for other fruits, allowing delivery of fresh fruits to areas they do not normally reach, the researchers suggested.
“We have identified some chemicals, polyamines, that allow the tomato plant to resist shriveling, to stay more healthy for a longer time. It lengthened shelf life by seven to eight days,” said Avtar K. Handa, PhD, a professor of horticulture at Purdue in West Lafayette, Ind. Dr. Handa is senior author of a paper showing that overexpression of yeast spermidine synthase impacted ripening, senescence, and decay symptoms in tomatoes (Nambeesan S, Datsenka T, Ferruzzi MG, et al. [Published ahead of print June 24, 2010.] Plant J. ).
The researchers introduced the yeast gene into tomatoes, increasing their production of spermidine. The transgenic fruits had longer shelf life, reduced shriveling, and delayed decay symptom development in comparison with wild-type tomatoes.
Similar results could be achieved by screening for tomatoes with high levels of expression of the gene, Dr. Handa said.
“We can put the gene in food crops, but that is not acceptable to a lot of populations,” he said. “Entirely through natural variation, we can get a high level of polyamines and breed in that attribute.”
Dr. Handa noted that this finding may be applicable to “a wide range of fleshy fruits. We are using the tomato as a model system to understand what controls the food quality.”