Norwich, UK — A valuable molecule sourced from the soapbark tree and used as a key ingredient in vaccines has been replicated in an alternative plant host for the first time, opening unprecedented opportunities for the vaccine industry.  A research collaboration led by the John Innes Centre used the recently published genome sequence of the Chilean soapbark tree (Quillaja saponaria) to track down and map the elusive genes and enzymes in the complicated sequence of steps needed to produce the molecule QS-21. Using transient expression techniques, the team reconstituted the chemical pathway in a tobacco plant, demonstrating for the first time ‘free-from ‘tree’ production of this highly valued compound. Professor Anne Osbourn said: “Our study opens unprecedented opportunities for bioengineering vaccine adjuvants. We can now investigate and improve these compounds to promote the human immune response to vaccines.” Vaccine adjuvants are immunostimulants which prime the body’s response to the vaccine.