By Emily Unglesbee , DTN Staff Reporter
January 31, 2020
ROCKVILLE, Md. (DTN) -- The next decade will bring some novel cotton technology to U.S. farmers. We rounded up four new cotton traits in the pipeline -- three winding their way toward commercialization and one ready to hit fields in 2020. They include a new Bt cotton trait targeting tarnished plant bug and thrips, HPPD-tolerant cotton, low-gossypol cotton and reniform-resistant varieties.
BT COTTON FOR PLANT BUGS AND THRIPS
For more than 20 years, the Bt traits on the cotton market have only targeted caterpillar pests of cotton, such as the cotton bollworm. Now, Bayer is working to bring a new Bt cotton variety that targets a completely different class of insects -- biting and sucking pests, namely tarnished plant bugs and thrips.
Also known as lygus, the tarnished plant bug has long been one of cotton growers' most damaging pests. In 2018, it cost growers an estimated $175 million across the U.S., according to Mississippi State University's annual cotton crop loss study. The study ranked it as the second most damaging cotton insect, just behind bollworm. Thrips was another top contender, costing growers an estimated $67 million in 2018.
Bayer's new trait, MON88702, branded ThryvOn, will contain the Bt protein mCry51Aa2, which targets two types of plant bug -- Lygus lineolaris (tarnished plant bug) and Lygus hesperus (western tarnished plant bug) -- and also shows control of thrips.
Pending regulatory approvals, Bayer hopes to commercialize the trait in the early 2020s, said Bayer spokesperson Brian Leake. "We've made the necessary submissions with the USDA, FDA and EPA to secure U.S. approvals," he told DTN.
"We have completed the FDA consultations and anticipate receiving USDA and EPA approvals in the near future." The ThryvOn trait will be stacked with Bayer's Bollgard 3 XtendFlex technology, which contains three Bt traits targeting caterpillar pests, as well as tolerance to dicamba, glyphosate and glufosinate, Leake added.
Cottonseed is a good source of protein for ruminants, but livestock such as chickens and pigs have long missed out on it as a feed option. Why? In a savvy evolutionary move, the cotton plant produces gossypol, a compound that helps protect it against insects and diseases but is toxic for non-ruminant animals and humans.
Enter Texas A&M geneticist Keerti Rathore, who has spent more than two decades creating a low-gossypol cottonseed trait. With funding from the industry group Cotton Inc., Rathore used a genetic engineering technique called RNA-interference (RNAi) to shut off the expression of a key cotton gene, but only in the seed.
The cotton leaves, bolls, roots and stem all still contain the valuable gossypol protection, but the seed has extremely low levels of the compound. "It drops levels of gossypol from 10,000 parts per million (ppm) to 300 ppm -- a 97% reduction," Rathore explained. "This is below the level FDA considers safe even for human consumption, 450 ppm."
The trait, TAM66274, has made its way through the U.S. regulatory system, with USDA deregulating it in October 2018 and FDA signing off in October 2019. Since some cottonseed is exported, however, securing import approvals from international trade partners is next on the docket, as is finding a commercial seed company to license the trait and create varieties with it, Rathore said.
Even without import approvals, Rathore believes the trait could be stewarded to avoid export markets, by sending the cottonseed protein directly to domestic livestock operations.
The cottonseed oil would not contain any trace of the GM trait and would be free to enter the commercial oil market, he added. "I'm hoping this would be available to growers between the next 5 to 10 years," Rathore said. "We're talking to all the players."
The herbicide landscape in cotton is getting complex. Most recently, new varieties tolerate in-season applications of glyphosate, dicamba and glufosinate (XtendFlex) and glyphosate, 2,4-D-choline and glufosinate (Enlist). Now BASF is preparing to add an HPPD-tolerant cotton trait to the market by 2024, pending regulatory approvals, said BASF spokesperson Casey Allen.
The trait, GHB811, offers tolerance to the HPPD-inhibiting herbicide isofluxatole for preemergence or early postemergence applications, Allen said. The HPPD-tolerant trait will be stacked with GlyTol (glyphosate tolerance), LibertyLink and Xtend traits, as well as TwinLink Plus, which offers three Bt proteins that target caterpillar pests.
The only non-biotech trait of the roundup is PhytoGen's native trait that supplies resistance to reniform nematodes. This parasitic pest robs cotton growers of more than 205,000 bales per year, according to the National Cotton Council Disease Loss committee's 2018 report. According to a Corteva Agriscience press release, the reniform-resistant varieties were showcased in on-farm trials during the 2019 growing season.
They will be available for PhytoGen Horizon Network growers in 2020, and the company is planning for a full commercial launch in 2021.
The trait will be stacked with Enlist technology for herbicide tolerance and Widestrike 3, which contains three Bt proteins targeting the bollworm (W3FE).