13 - Genes involved in the biosynthesis of aroma volatiles and biotechnological applications

Abstract

Publisher Summary Aroma volatiles contribute to a large extent to the overall sensory quality of fruit and vegetables. The strategies developed to improve aroma volatiles emitted by fruits and vegetables include a wide range of targets comprising the different metabolic pathways and also regulatory elements, such as hormones and transcription factors, and finally mechanisms involved in the storage or sequestration of volatile precursors, such as glycosylation and storage into the vacuoles. The production of aroma volatiles can be affected by engineering other fruit attributes. For instance, down-regulation of Polygalacturonase (PG), Pectin Methyl Esterase (PME), and PG+PME in transgenic fruit that results in lower degradation of pectins can reduce flavor volatiles by a so far unexplained mechanism. This chapter reviews the information available on genes and gene families identified as participating in the synthesis of different class of aroma volatiles. It also describes the potential biotechnological applications for improved aromas in fruit and vegetables and other perspectives. The chapter presents a schematic representation of the steps of aroma volatiles biosynthesis for which genes have been characterized and used as targets for genetic transformation, where genes that have been up- or down-regulated by genetic engineering are shown under grey background.