CRISPR Boosts Resistant Starch in Potato

Researchers from Himachal Pradesh University, ICAR-Central Potato Research Institute, and ICAR-Indian Institute of Wheat and Barley Research in India have successfully developed high-amylose potatoes using CRISPR-Cas9. The team targeted two starch-branching enzyme genes, SBE2.1 and SBE2.2, in the widely grown potato variety Kufri Chipsona-I to increase its resistant starch content.

Using Agrobacterium-mediated transformation, the researchers generated 50 edited potato lines, 70% of which were found positive for bar and Cas9 genes. Six mutant lines, K301, K302, K303, K304, K305, and K306, exhibited deletions and substitutions in the target exons. Among these mutant lines, K304 was the most efficiently edited, containing both insertion-deletion and substitution mutations in three out of the four selected targets across both genes.

The study showed that the harvested tubers from the SBE2.1 and SBE2.2 mutant K304 line showed the highest amylose (95.91%) and resistant starch content (8.69 g/100 g). Further analyses revealed that these mutants illustrated an altered crystallinity index and a substantial decline in branch chain elongation in amylopectin. The researchers conclude that CRISPR-Cas9-mediated mutagenesis of starch biosynthesis genes is an effective strategy for developing potato varieties with improved nutritional profiles and health benefits.

For more information, read the study from Frontiers in Genome Editing.