Recent developments and practical applications of new breeding technologies
The global tobacco industry has enjoyed a relatively stable leaf supply over decades due, in part, to incremental germplasm improvements through traditional breeding, common agronomic practices and harmonized regulatory frameworks. However, this stability is becoming increasingly fragile as governments continue to expand their authority over tobacco products sold within their borders. Regulatory standards can, in some instances, be addressed simply through product design changes. However, FDA’s recently proposed regulations for smokable and smokeless products sold in the United States are so stringent that genetic modifications may be the only way to achieve such drastic limits. Given that the industry continues to oppose GMO utilization, New Breeding Technologies (NBTs) not involving DNA integration may offer the best solution to create tobaccos that could be used to create products meeting regulatory requirements within time limitations initially suggested by the FDA.
NBTs have improved in efficacy and precision over the past decade. For example, EMS created mutant lines (ZYVERT® Technology) have shown NNN reductions of up to ~75 % in leaves and moist smokeless tobacco products. ZYVERT® Technology required ~10 years and 8 generations for stable line creation. In contrast, CRISPR editing of select nicotine biosynthetic genes has taken ~3 years and 3 generations for stable line creation.
NBT effectiveness in developing commercial germplasm is enhanced by advancements in genome sequencing, analyses of transcriptomes, metabolomes and proteomic datasets of multiple tissues collected at various time intervals. Whole genome Axiome® SNPchip characterization also facilitates rapid trait introgression. However, regulatory harmonization in regards to the non-GMO status of NBTs is needed to avoid costly segregation practices and global trade disruptions.