Question

Is it easier to control the timing of fruit ripening of a transgenic tomato expressing the antisense strand of ACC synthase OR the mutant, Never-ripe tomato? Explain your answer

Answer 1

The enzymes like ACC synthase and ACC oxidase, in plants controls the synthesis of plant hormone ethylene, ethylene plays a critical role in ripening.

Inhibition of these enzymes has been targeted in transgenic variety of tomato to delay the ripening by using antisense RNA technique. Antisense fruit in which ACC synthase or ACC oxidase are inhibited show slower ripening and reduced over-ripening. ACC oxidase antisense genes have also been shown to delay leaf senescence.

The commercially available variety of transgenic tomato is The FLAVR SAVR™ tomato was developed through the use of antisense RNA to regulate the expression of the enzyme polygalacturonase in ripening tomato fruit. This enzyme is one of the most abundant proteins in ripe tomato fruit and has long been thought to be responsible for softening in ripe tomatoes