Issue link: https://read.dmtmag.com/i/787641
www.goodfruit.com GOOD FRUIT GROWER FEBRUARY 15, 2017 15 I decided to try it," Di said. Previously, she had used a different genetic engineering technique that could turn down — but not turn off — the expression of host fac- tor genes in soybeans to make them more resistant to nematodes. "We know if we knock down the interaction of the host factors, we know we can improve resistance, so if it's completely knocked out, we can improve resistance even more," Di said. "And now with gene editing technology, it's much easier to knock out a gene." Gene-editing with CRISPR works by pairing an enzyme and a guiding piece of genetic code known as RNA to a specifi c site in the DNA, where the enzyme, known as an endonuclease, makes a precise cut. Then, the cell's own DNA repair mechanism puts a new DNA piece, supplied by the scientist, into the newly created gap. It could be an entirely new gene, or, as is the case in Di's work, just a tiny change that renders the existing gene unable to be translated into the proteins that work as that welcome mat for invading fungi. "It's very targeted; we can direct the DNA endonucle- ases where we want so we don't have to hurt the plant in other ways. We only knock out the gene I choose," Di said. The technique worked well in the Arabidopsis test, so Di has begun to use it to transform the comparable host genes in Chardonnay grape cells in her lab. If it works as she expects it to, it won't be hard to replicate the pro- cedure to make other grape varieties resistant to downy mildew as well because the host factor genes are similar in each variety, Di said. Since the sophisticated CRISPR technique requires no transfer genes from other species, like some tradi- tional means of genetic engineering that have spurred controversy, it's unclear at this time if crops altered this way will be considered genetically modifi ed organisms by regulators. And it remains to be seen if the wine industry in New Jersey and other regions where downy mildew is a signif- icant problem will embrace Di's genetically engineered grape. But Ward said that ending growers' dependence on fungicides would have multiple benefi ts. "It's really the pursuit of reduced pesticide residue on the fruit from the consumers' point of view and reduced need for applications from the producers' point of view and reduced environment impacts of pesticides, which is a benefi t from everyone's point of view," Ward said. "Wine grape growers as a group tend to be well educated and sophisticated folks … they are out there trying to optimize their use of any technology we develop." • Finally, the cell's repair mechanism fi xes the cuts with the new DNA piece in place. GOOD FRUIT GROWER ILLUSTRATION © 2017, Trécé Inc., Adair, OK USA • TRECE, PHEROCON and CIDETRAK are registered trademarks of Trece, Inc., Adair, OK USA PLEASE: ALWAYS READ THE LABEL INSEC T PHEROMONE & KAIROMONE SYSTEMS INCORPORATED ® Your Edge – And Ours – Is Knowledge. Contact your local supplier and order now. Visit our website: www.trece.com or call 1- 866 -785-1313. TRE-1034, 1/17 • Comparison of active ingredient delivered based on optional label rates. • Application cost based on growers assessment of commercial use at the labor rate of $12/hour. • Labor cost may vary with employee training experience and productivity. Clearly More Active Product… Lower Application Cost! • Comparison of active ingredient delivered based on optional label rates. • Application cost based on growers assessment of commercial use at the labor rate of $12/hour. • Labor cost may vary with employee training experience and productivity. The ONLY Mating Disruption Systems that disrupt both MALE…and FEMALE Codling Moth. CIDETRAK ® CMDA COMBO ™ Puzzle Piece (PP) CIDETRAK ® CMDA COMBO ™ MESO ™ E N H A N C E D C O D L I N G M OT H M AT I N G D I S R U P T I O N CIDETRAK CMDA COMBO GFG ad.indd 1 1/26/17 5:09 PM