Vanillin biosynthetic pathways in plants

Abstract

The present review compiles the up-to-date knowledge on vanillin biosynthesis in plant systems to focus principally on the enzymatic reactions of in planta vanillin biosynthetic pathway and to find out its impact and prospect in future research in this field. Vanillin, a very popular flavouring compound, is widely used throughout the world. The principal natural resource of vanillin is the cured vanilla pods. Due to the high demand of vanillin as a flavouring agent, it is necessary to explore its biosynthetic enzymes and genes, so that improvement in its commercial production can be achieved through metabolic engineering. In spite of significant advancement in elucidating vanillin biosynthetic pathway in the last two decades, no conclusive demonstration had been reported yet for plant system. Several biosynthetic enzymes have been worked upon but divergences in published reports, particularly in characterizing the crucial biochemical steps of vanillin biosynthesis, such as side-chain shortening, methylation, and glucoside formation and have created a space for discussion. Recently, published reviews on vanillin biosynthesis have focused mainly on the biotechnological approaches and bioconversion in microbial systems. This review, however, aims to compile in brief the overall vanillin biosynthetic route and present a comparative as well as comprehensive description of enzymes involved in the pathway in Vanilla planifolia and other plants. Special emphasis has been given on the key enzymatic biochemical reactions that have been investigated extensively. Finally, the present standpoint and future prospects have been highlighted.

Selection and validation of reference genes for measuring gene expression in Toona ciliata under different experimental conditions by quantitative real-time PCR analysis

“…It may help to pest control by obtaining insect-resistant plants through molecular breeding. In order to synthesize a desired compound related to the resistance mechanism, it is necessary to first explore the pathway and its related regulatory genes [14,15]. Gene expression analysis is one of the most powerful tools to explore biosynthetic and insect-resistance mechanisms in T. ciliata.…”

Benzaldehyde Synthases Are Encoded by Cinnamoyl-CoA Reductase Genes in Cucumber (Cucumis sativusL.)

“…Here we 15 demonstrated two types of BSs (interestedly, one in peroxisome, and another in cytosol) are responsible for benzaldehyde in cucumber. Our study also provide novel insight to the unsolved vanillin (one aromatic aldehyde with similar structure to benzaldehyde) biosynthesis [30]. Table S1.…”

Strategies for the production of biochemicals in bioenergy crops

“…Despite its economic importance, the vanillin/syringaldehyde biosynthetic pathway in plants has not been fully elucidated [107]. Nevertheless, several engineering approaches have resulted in augmentations of these two aromatics in biomass.…”