Crop improvement represents the genetic alteration of plants to gratify
human needs. Crop improvement, the art of engineering plants for the benefit of
humankind, is as old as agriculture itself. Even though crop improvement programs
focus on the development of novel crop varieties with enhanced quality and tolerance
to ecological stresses (both biotic and abiotic) and making crops able to give more
yield exhibiting good quality. Still, we cannot rely on the crops due to various reasons,
like the irritating nature of onion, low lysine and threonine content in Maize, the
presence of toxic Gossypol in cotton, etc. These irritating qualities of the crop must be
reduced or removed by genetically modifying the crop plants, and then only it will be
accepted for human consumption. Expression of antisense genes and the related genesilencing
technique has been exploited as an applied technique in plant biotechnology
for creating “metabolic engineered plants” in which the endogenous target gene, which
is responsible for the unpleasant character is specifically suppressed. The antisense and
its related technology are used for various purposes such as silencing or ablating
undesired genes. In the present chapter, the down-regulation of the enzyme using the
gene-silencing technique used in various crop varieties are discussed in detail.
Keywords: Antisense, Crop, Down-regulation, Enzyme, Flavr-Savr, Gossypol,
Improvement, Inhibition, Polygalacturonase, RNA-silencing, Tearless-onion.
