CRISPR-Cas9 Editing Opens New Paths for Forage Improvement

Scientists from China have established a CRISPR-Cas9 gene-editing system in black medic (Medicago lupulina), a high-protein leguminous forage crop used as livestock feed and a nitrogen-fixing cover crop. By targeting and knocking out the MlPINNA1 gene, which is involved in compound leaf development, the researchers converted the species' typical trifoliate leaves into pinnate pentafoliate leaves. The established gene-editing system could enable the modification of other forage-related traits for developing improved forage crops and supporting the genetic improvement of related species such as alfalfa.

To establish the gene-editing and plant regeneration system, the researchers optimized culture conditions and designed a CRISPR-Cas9 construct targeting the MlPINNA1 gene. Three independent gene-edited plants were obtained, with insertions and deletions at the target sites confirmed through sequencing. All three edited lines developed pentafoliate leaves, confirming the role of MlPINNA1 in leaf development.

While further studies will be needed to determine whether the pentafoliate trait itself leads to greater biomass, the successful modification of MlPINNA1 demonstrated the potential of gene editing to precisely alter traits in black medic. The established framework could be utilized to investigate and manipulate genes involved in forage production and quality, potentially improving the quantity and nutritional value of forage and supporting more nutritious feed and sustainable livestock production.

You may read the study in the Journal of Integrative Plant Biology to learn more.