Editing the Genome of Wolffia australiana

Abstract

The genus Wolffia has not been the focus of biotechnological interest so far in contrast to Lemna and Spirodela. There are only a few publications on cultivation and regeneration and even fewer articles about transformation of species from this genus. However, Wolffia has great potential, because it can grow both floating and submerged, which allows for the production of a larger biomass compared to other genera. Furthermore, the in planta transformation is feasible, which may accelerate the development of new lines, since there is no need for time-consuming plant regeneration. The groundbreaking technology of genome editing allows the deletion, substitution, or insertion of genes at precise, predefined sites in the genome. Here, we present as proofs of principle the crucial steps needed to realize Wolffia australiana as a plant bioreactor. The procedures described include the cultivation and transformation of W. australiana, the identification of a suitable gene for genome editing, which can be used as a selectable marker as well, and the method of genome editing of duckweed itself, which resulted in knockout Wolffia plants.