Genetic regulation and manipulation of nicotine biosynthesis in tobacco: strategies to eliminate addictive alkaloids

Tobacco (Nicotiana tabacum L.) is a widely cultivated crop of the genus Nicotiana. Due to the highly addictive nature of tobacco products, tobacco smoking remains the leading cause of preventable death and disease. There is therefore a critical need to develop tobacco varieties with reduced or non-addictive nicotine levels. Nicotine and related pyridine alkaloids biosynthesized in the roots of tobacco plants are transported to the leaves, where they are stored in vacuoles as a defense against predators. Jasmonate, a defense-related plant hormone, plays a crucial signaling role in activating transcriptional regulators that coordinate the expression of downstream metabolic and transport genes involved in nicotine production. In recent years, substantial progress has been made in molecular and genomics research, revealing many metabolic and regulatory genes involved in nicotine biosynthesis. These advances have enabled us to develop tobacco plants with low or ultra-low nicotine levels through various methodologies, such as mutational breeding, genetic engineering, and genome editing. We review the recent progress on genetic manipulation of nicotine production in tobacco, which serves as an excellent example of plant metabolic engineering with profound social implications. Molecular and genomics studies have revealed metabolic and regulatory genes involved in nicotine biosynthesis, enabling us to develop tobacco plants with ultra-low nicotine levels through mutational breeding, genetic engineering, and genome editing.

Automated summary

Tobacco is a widely cultivated crop, but its highly addictive nature poses a significant risk to human health. Recent research in molecular and genomics has led to advancements in understanding the metabolic and regulatory genes involved in nicotine biosynthesis, allowing the development of tobacco plants with ultra-low nicotine levels through mutational breeding, genetic engineering, and genome editing.