Leaf Science research underpins our harm reduction and sustainable farming programmes that benefit both consumers and farmers.
In 2017 we published a gold-standard assembly of the tobacco genome – a significant achievement given the genomic complexity of tobacco. Rather than keeping the sequence proprietary, we chose to publish it along with tools that are important for examining the genome, as a central resource for scientists around the world.
The challenge now is to understand the underlying genetic pathways within the tobacco plant so that we can breed new cultivars or varieties with improved characteristics.
This is no mean feat as, at current estimates, the tobacco genome contains 69,500 genes and further analysis is expected to reveal even more. Given the enormous data sets, we use computational biology to screen and identify candidate genes, and for predictive breeding. We then clone and test candidate genes by incorporating them into plants.
We have automated a lot of the processes involved and are applying practices from academic research to our industrial laboratories to speed up operations. For instance, we have developed a way of transforming tobacco (so it takes up genetic material from its surroundings) called floral infiltration that produces transformed seed in six weeks compared to a year by the standard process. And, using an early flowering plant, we can go from seed to seed in only eight weeks instead of eight months.
Five years ago we were cloning thirty genes a year and it took us three years to get to field trials, whereas today we’re cloning and testing up to sixty genes a week and can have them in field trials within six months.
Once we’re happy with the evidence supporting our gene targets, we transfer them to BAT’s Leaf Research division, our breeding and agronomy group that turns gene discoveries into commercial varieties. We have two field trial locations in different hemispheres (Brazil and North America), enabling trials year-round.
We have already identified which tobacco genes are involved in producing two key toxicants (tobacco-specific nitrosamines NNK and NNN) identified by the World Health Organization for mandated lowering in tobacco smoke, and we are now developing novel tobacco cultivars that contain lower levels of those carcinogenic compounds for use in new category products. By applying the same gene discovery practices, we are also finding taste-improvement targets for use in breeding to develop bespoke tobacco varieties that will improve the flavour of our tobacco heating products. And by establishing which genes are involved in growing crops with increased yields and improved disease resistance, we are modifying these traits to help our farmers grow tobacco more sustainably.
Meanwhile, as we improve the quality of the genome assembly, we continue to make all our findings publicly available.