The researchers learned that the astonishing diversity of cadherin
in pink bollworm from India is caused by alternative splicing, a novel mechanism of resistance that allows a single DNA sequence to code for many variants of a protein.
Farmers in the U.S., but not in India, adopted tactics designed to slow evolution of resistance
in pink bollworm.
Not exact matches
«Perhaps the most compelling evidence that refuges work comes from the
pink bollworm, which evolved resistance rapidly to Bt cotton
in India, but not
in the U.S.,» Tabashnik said.
In 2009, researchers in Arizona tested transgenic pink bollworm moths, which threaten cotton field
In 2009, researchers
in Arizona tested transgenic pink bollworm moths, which threaten cotton field
in Arizona tested transgenic
pink bollworm moths, which threaten cotton fields.
The emergence of resistant
pink bollworm in India provided the researchers an opportunity to test the hypothesis that insects
in the field would evolve resistance to Bt toxin by the same genetic mechanism found previously
in the lab.
Their findings, reported
in the May 19 issue of the journal PLOS ONE, shed light on how the global caterpillar pest called
pink bollworm overcomes biotech cotton, which was designed to make an insect - killing bacterial protein called Bt toxin.
In the U.S., pink bollworm populations have not evolved resistance to Bt toxins in the wil
In the U.S.,
pink bollworm populations have not evolved resistance to Bt toxins
in the wil
in the wild.
However, resistant
pink bollworm populations have emerged
in India, which grows the most Bt cotton of any country
in the world.
Scientists from the UA and the U.S. Department of Agriculture worked closely with cotton growers
in Arizona to develop and implement resistance management strategies such as providing «refuges» of standard cotton plants that do not produce Bt proteins and releasing sterile
pink bollworm moths.
He said that by collaborating with Indian scientists, «we discovered that the same cadherin gene is associated with the resistance
in India, but the mutations are different and much more numerous than the ones we found
in lab - selected
pink bollworm from Arizona.»
As a result,
pink bollworm has been all but eradicated
in the southwestern U.S. Suppression of this pest with Bt cotton is the cornerstone of an integrated pest management program that has allowed Arizona cotton growers to reduce broad spectrum insecticide use by 80 percent, saving them over $ 10 million annually.
«We wanted to see if field - resistant
pink bollworm from India harbored these same changes
in the cadherin gene,» Fabrick said.
Based on laboratory experiments aimed at determining the molecular mechanisms involved, scientists knew that
pink bollworm could evolve resistance against the Bt toxin, but they had to go all the way to India to observe this happening
in the field.
In addition to Fabrick and Tabashnik, the following authors collaborated on the study: Jeyakumar Ponnuraj from the National Institute of Plant Health Management in Hyderabad, India, who studied pink bollworm resistance as a visiting scholar in Tabashnik's lab; Amar Singh and Raj Tanwar of the National Centre for Integrated Pest Management at the Indian Agricultural Research Institute in New Delhi; and Gopalan Unnithan, Alex Yelich, Xianchun Li and Yves Carrière from the UA Department of Entomolog
In addition to Fabrick and Tabashnik, the following authors collaborated on the study: Jeyakumar Ponnuraj from the National Institute of Plant Health Management
in Hyderabad, India, who studied pink bollworm resistance as a visiting scholar in Tabashnik's lab; Amar Singh and Raj Tanwar of the National Centre for Integrated Pest Management at the Indian Agricultural Research Institute in New Delhi; and Gopalan Unnithan, Alex Yelich, Xianchun Li and Yves Carrière from the UA Department of Entomolog
in Hyderabad, India, who studied
pink bollworm resistance as a visiting scholar
in Tabashnik's lab; Amar Singh and Raj Tanwar of the National Centre for Integrated Pest Management at the Indian Agricultural Research Institute in New Delhi; and Gopalan Unnithan, Alex Yelich, Xianchun Li and Yves Carrière from the UA Department of Entomolog
in Tabashnik's lab; Amar Singh and Raj Tanwar of the National Centre for Integrated Pest Management at the Indian Agricultural Research Institute
in New Delhi; and Gopalan Unnithan, Alex Yelich, Xianchun Li and Yves Carrière from the UA Department of Entomolog
in New Delhi; and Gopalan Unnithan, Alex Yelich, Xianchun Li and Yves Carrière from the UA Department of Entomology.
By sequencing the DNA of resistant
pink bollworm collected from the field
in India — which grows the most Bt cotton of any country
in the world — the team found that the insects produce remarkably diverse disrupted variants of cadherin.
Back
in March of this year, however, Monsanto admitted that
pink bollworms had developed resistance to Bt cotton
in the Indian state of Gujarat,
in plots where the single gene variety (Bollgard I) of the GM crop was planted.