A series of independent non-transgenic mutations found in at least one deoxyhypusine synthase gene of tomato; tomato plants having these mutations in one or more of their deoxyhypusine synthase genes; and a method of creating and identifying similar and/or additional mutations in a deoxyhypusine synthase gene by screening pooled and/or individual tomato plants. The tomato plants of the present invention exhibit altered deoxyhypusine synthase activity and delayed post harvest softening of their tomato fruit without having the inclusion of foreign nucleic acids in their genomes. Novel nucleotide and protein sequences for deoxyhypusine synthases in tomato and their uses.
