When Tzann-Wei Wang and colleagues of the University of Waterloo, Canada suppressed the activity of deoxyhypusine synthase (DHS) in tomato plants, they found that the tomato fruits did not ripen as quickly as their conventional counterparts, and that, at higher levels of suppression, plants were sterile or had changes in plant structure. Their work, “Antisense Suppression of Deoxyhypusine Synthase in Tomato Delays Fruit Softening and Alters Growth and Development,” appears in this month’s Plant Physiology.

DHS is an enzyme present in eukaryotic cells, and participates in reactions that activate other enzymes, which in turn initiate protein translation. Researchers found, through RNA blotting, that the enzyme family activated by DHS likewise increased in expression as fruits began to age and soften.

Researchers suppressed the activity of DHS by expressing part of the enzyme’s untranslated region in tomato, resulting in antisense gene control for the plant. With much lower DHS activity in the transgenic tomato, researchers found that 1) transgenic fruits ripened normally, but exhibited delayed post-harvest softening and aging; 2) transgenic plants under strong DHS suppression were also male sterile and did not produce fruit; and 3) these same plants had larger, thicker leaves with higher levels of chlorophyll.

Read more in this month’s Plant Physiology. The article appears on pp. 1372-1382 of the journal.