Thlapsi arvense L. (pennycress) is being developed as a profitable oilseed cover crop for the winter fallow period throughout the temperate regions of the world, controlling soil erosion and nutrients run-off on otherwise barren farmland. We demonstrate that pennycress can serve as a user-friendly model system akin to Arabidopsis that is well-suited for both laboratory and field experimentation. We sequenced the diploid genome of the spring-type Spring 32-10 inbred line (1C DNA content of 539 Mb; 2n = 14), identifying variation that may explain phenotypic differences with winter-type pennycress, as well as predominantly a one-to-one correspondence with Arabidopsis genes, which makes translational research straightforward. We developed an Agrobacterium-mediated floral dip transformation method (0.5% transformation efficiency) and introduced CRISPR-Cas9 constructs to produce indel mutations in the putative FATTY ACID ELONGATION1 (FAE1) gene, thereby abolishing erucic acid production and creating an edible seed oil comparable to that of canola. We also stably transformed pennycress with the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene, producing low-viscosity acetyl-triacylglycerol-containing seed oil suitable as a diesel-engine drop-in fuel. Adoption of pennycress as a model system will accelerate oilseed-crop translational research and facilitate pennycress’ rapid domestication to meet the growing sustainable food and fuel demands.
Bibliographical noteFunding Information:
We thank Friedrich Fauser and Holger Puchta for providing the CRISPR-SpCas9 vectors, Li-hua Zhu for providing the pHAN vector, and Arvegenix, Inc. for providing an in-house generated Bar-selectable vector. We thank Terry Isbell for providing the Elizabeth and Beecher seeds. Special thanks to John Flemming, Dalton Williams, Brian Shade, Steve Ticknor, Annie Newark, and Andy Labroo for their assistance as undergraduate researchers in the lab. This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2014-67009-22305 to JCS and MDM and award number 2015-67013-22815 to TPD. Research conducted by TPD and EBC was supported by the U.S. Department of Energy, Office of Science, OBER (DOE BER SC0012459). Funds to support RC were provided by the Walton Family Foundation awarded to Donald Wyse (University of Minnesota).