Researchers have homed in on a gene that makes a variety of white lupin, a high-protein crop that could be an alternative to soybeans, taste sweeter. Lupins, they note, typically accumulate quinolizidine alkaloids that give them a bitter taste, which has limited their adoption. But white lupin has limited quinolizidine alkaloid levels. As they report in Science Advances, researchers from the University of Copenhagen and elsewhere examine the pauper locus, which confers that sweetness. By studying three white lupin varieties — the wild Graecus that is bitter, a bitter Ethiopian landrace, and the sweet pauper cultivar Amiga — the researchers found that the locus encompasses an acetyltransferase gene. The Amiga cultivar harbored four variants in that gene that the others did not, and those variants affect acetyltransferase activity. In a larger panel of plants, one SNP in particular was never found in a bitter plant. Through a mutagenesis analysis of narrow-leafed lupin, a typically bitter variety, they could replicate the pauper chemotype. "The creation of a non-GMO, sweet narrow-leafed lupin line by knocking out the orthologous gene demonstrates the potential to kick-start the domestication of novel legume crops via similar strategies," the researchers add.