One gene switch controls potato's natural toxin production
Liu Y, Merino I, Potgieter L, Flöhr A, Johansson AI
Crispr
The next time you leave a bag of potatoes near a sunny window and see them turn green, you're watching this exact gene in action, ramping up production of the bitter, toxic compounds that make light-exposed spuds unsafe to eat.
Potatoes naturally make toxic bitter compounds called glycoalkaloids to defend themselves from pests, and these toxins spike when the tuber is cut, bruised, or exposed to light, which is why you're told to toss green potatoes. Researchers found and disabled a single gene, GAME9, that acts as the master control switch for this whole toxin-making process, and plants without it stayed almost completely toxin-free in their tubers even under stress, all while growing and looking completely normal otherwise. This points to a promising way to breed potatoes that stay safer to eat longer without sacrificing yield or plant health.
Key Findings
CRISPR/Cas9 knockout of StGAME9 in potato drastically reduced steroidal glycoalkaloid (SGA) levels in leaves and left tubers almost entirely SGA-free
Mutant tubers failed to ramp up SGA production even under two classic inducing stresses, wounding and light exposure, showing loss of the inducible defense response
Combined transcriptomic and metabolomic analysis revealed StGAME9 influences a broad network beyond SGAs, including sterol pathways and stress metabolism, yet mutant plants grew normally in both greenhouse and field conditions
chevron_right Technical Summary
Scientists disabled a single gene called GAME9 in potato plants and found it acts as a master switch for producing toxic bitter compounds called glycoalkaloids. Without this gene, potato tubers stayed almost completely free of these natural toxins, even when stressed by wounding or light, while the plants still grew normally.
Abstract Preview
Original paper
Loss of function of the AP2/ERF transcription factor StGAME9 abolishes activation and induction of steroidal glycoalkaloid biosynthesis in potato plants.
Steroidal glycoalkaloids (SGAs) are toxic defense substances present in certain species of the Solanaceae, including major crops such as eggplant, tomato, and potato. GLYCOALKALOID METABOLISM 9 (GA...
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The potato is a starchy tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant Solanum tuberosum, a perennial in the nightshade family Solanaceae.