Berry good news: CRISPR editing optimizes goldenberries for large-scale farming
Using CRISPR to engineer a relative of the tomato, biologists have created a fruit that is easier to grow, potentially opening the door to breeding plants that are resistant to disease, pests or drought.
In a recent study, scientists from Cold Spring Harbor Laboratory (NY, USA), Johns Hopkins University (MD, USA) and the Boyce Thompson Institute (NY, USA) have used CRISPR gene editing to create goldenberries that are more suited to large-scale farming. Bypassing the traditional, long-winded breeding process, they provide more resilient food crops that could help expand dietary diversity.
The goldenberry (Physalis peruviana), with its sweet, yellow-orange berries, is a minor crop cultivated in limited geographical regions. Native to South America, the fruit is a member of the Solanaceae or nightshade family, which also includes potatoes and tomatoes. It is said to taste like pineapple and mango and is nutritionally rich, often touted as a superfood, giving it great potential as a global crop.
However, the plants have undergone little domestication, and as such are large and unruly, making them unmanageable for large-scale production. Improving their growth habit to rectify this could put these berries on the menu in many more places and therefore have a positive impact on dietary diversification.
Previous work in sister species, tomatoes and groundcherries, has demonstrated that genome-editing technologies like CRISPR can be used to produce more compact plants by engineering mutations in the ERECTA gene, which regulates stem length.
Building on this work, the researchers applied the same strategy to target tetraploid goldenberries, aiming to modify two ERECTA genes to produce plants with a more agriculturally desirable architecture.
First, they assembled high-quality genomes for two populations of the plant, hailing from India and South Africa. This enabled them to detect two highly similar ERECTA (Pper-ER) genes, Pper-ER-A and Pper-ER-B, allowing the design of a four-gRNA construct for simultaneous targeting. At the same time, they developed plant regeneration, transformation and gene-editing approaches.
First-ever oat pangenome may put climate-smart oats on the breakfast menu
Complexity of the oat’s DNA has long resisted detailed study; now, the first-ever oat pangenome has been established.
CRISPR-Cas9-mediated gene editing led to the recovery of two notable null alleles of Pper-ER in the India ecotype: one base pair deletion in Pper-er-A and one base pair insertion in Pper-er-B. The team then introgressed both null alleles into the South Africa line, as there tends to be a preference for this line’s flavor.
Following two rounds of backcrossing the edited lines into the South Africa line and a final self-pollination, the researchers had created plants with substantially increased compactness and fruits similar to commercially available ones.
In subsequent generations, they tasted the fruits and made selections based on flavor, ultimately breeding two distinct lines of the most delicious and compact goldenberry plants, suitable for production.
At 3 months old, the edited crops were 35% shorter than their wild relatives, and the number of fruits produced per plant was not affected by the mutations, although the fruits were slightly smaller.
“These new compact plants can be grown at higher density, don’t require extensive staking or trellising, and are much easier to maintain and harvest,” study author Joyce Van Eck extolled.
The team has already secured clearance by the US Department of Agriculture, confirming that the edited varieties are not plant pests, and is seeking approval by the US Food and Drug Administration (MD, USA) to enable growers to move forward with commercial production.
Next, they hope to expand this approach to other underutilized crops and potentially even tackle additional desirable traits like fruit size or disease, pest and drought resistance.
“By using CRISPR, you open up paths to new and more resilient food options,” added Blaine Fitzgerald. “In an era of climate change and increasing population size, bringing innovation to agricultural production is going to be a huge path forward.”