CRISPR technology for product development using hybrid aspen and Eucalyptus as models

Important results from the project

The project aimed at enabling commercial use of CRISPR-Cas9 in trees by (A) building a system that allows efficient gene testing in a model species and (B) by enhancing the transformation capabilities in a commercial species, e.g. Eucalyptus. In (A) a new vector system was built that enables efficient gene editing and inactivation in a one step solution. In (B) several factors enhancing transient expression during transformation was tested which enables production of transgene free CRISPR modified trees. Efficient identification of modified shoots was also addressed.

Expected long term effects

Methods developed and implemented in (A) is a solid base for large scale testing with CRISPR modification of trait genes in field trials, a necessity for commercialization of new genetically enhanced trees. The new vector system is the core in this development. For production of transgene free Eucalyptus (B) the establishment of an improved protocol with increased transient expression and more efficient identification of modified shoots is of great importance. The production of transgene free modified trees eliminates the need to cross out the foreign DNA.

Approach and implementation

In building the vector system we started with five strategies, three were evaluated and two strategies are working as expected. The thorough background work has given a broader understanding of the processes and resulted in a well thought out and flexible system. In developing the transformation protocols, we evaluated different hormones affecting development and growth early during transformation and regeneration. By using media with and without selection during shoot regeneration we have increased our knowledge regarding different transformation events in the same tissue.