Tomatoes That Soften More Slowly Post-Harvest Due To Non-Transgenic Alterations In An Expansin Gene

Abstract

A series of independent human-induced non-transgenic mutations found in an expansin gene (LeExp1) of tomato; tomato plants having these mutations in their LeExp1 genes; and a method of creating and identifying similar and / or additional mutations in the LeExp1 gene by screening pooled and / or individual tomato plants. The tomato plants of the present invention exhibit fruit that soften more slowly post-harvest without having the inclusion of foreign nucleic acids in their genomes.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 077,453, filed Jul. 1, 2008.FIELD OF THE INVENTION[0002]This invention relates to human-induced non-transgenic mutations in an expansin gene of tomato, particularly, LeExp1, and tomato plants having such non-transgenic mutations in at least one of their expansin genes, more particularly, an LeExp1 gene. This invention further relates to tomato plants having delayed post-harvest softening of their fruits as a result of non-transgenic mutations in at least one of their LeExp1 genes. This invention further relates to a method of creating non-transgenic tomato plants exhibiting delayed post-harvest fruit softening. In addition, this invention concerns a novel partial genomic DNA sequence for LeExp1.BACKGROUND[0003]One of the main challenges facing the tomato industry is how to deliver to a processing plant or to the marketplace tomato fruit that have been vine-ripened ...

AI Technical Summary

Benefits of technology

[0009]In accordance with one exemplary embodiment, this invention includes a tomato plant, tomatoes, seeds, plant parts and progeny thereof exhibiting a decreased rate of post-harvest softening caused by a human induced non-transgenic mutation in at least one LeExp1 gene.

[0011]In accordance with yet another exemplary embodiment, this invention includes food and food products incorporating fruit from tomato plants exhibiting a decreased rate of post-harvest softening caused by a human-induced non-transgenic mutation in at least one LeExp1 gene.

Problems solved by technology

One of the main challenges facing the tomato industry is how to deliver to a processing plant or to the marketplace tomato fruit that have been vine-ripened (i.e., desirable to consumers in taste, texture, and color) but that remain firm without the usual softening that reduces the shelf life of harvested fruit.

Because traditional breeding methods are very labor intensive, it could take years to develop a novel tomato variety that may display only a modest increase in shelf life.

These data suggest that modulation of LeExp1 levels in tomatoes affects fruit softening, a key factor that limits the shelf life of fresh tomatoes.

However, public acceptance of genetically modified plants, particularly with respect to plants used for food, is not universal.

However, these methods are both laborious and time-consuming.

In addition, undesirable characteristics often are transferred along with the desired traits when tomato plants are crossed in traditional breeding programs.

However, to date, a naturally occurring “knockout” or “knockdown” of any endogenous tomato expansin gene is not known in the art.

These findings indicate the lack of natural genetic variation in the LeExp1 gene of germplasm that is available to tomato breeders.