18 October 1991
Vol 254, Issue 5030

About The Cover

Senescence in fruit can be prevented by inhibiting the synthesis of the fruit-ripening hormone ethylene with the use of antisense RNA in transgenic tomatoes. The normal fruits on the left produce ethylene and ripen normally; the antisense-containing fruits in the middle fail to ripen. Treatment of antisense fruits with exogenous ethylene restores ripening (fruits on the right). See page 437. [Photo by Stephen Gladfelter, Stanford University Medical Center]