Monsanto Developing 24-Hour Glyphosate Resistance Test Kit
25 September 2013 
Monsanto is developing a method for detecting glyphosate resistance in crops in just 24 hours, using a dye that changes color. Dale Shaner, a plant pathologist who recently retired from the USDA ARS Water Management Research Unit, plans to help Monsanto fine-tune the technology.
“Widespread use of glyphosate, often to the exclusion of other herbicides, ensured that weeds capable of surviving glyphosate would thrive. Now that we’re seeing that happen, we need to address it,” Shaner said.
According to USDA, scientists can determine whether a weed will resist glyphosate by measuring the amount of a compound known as “shikimate” in its tissues. Glyphosate kills weeds by interfering with production of aromatic amino acids, and shikimate plays a key role in producing those amino acids. It is the “shikimate pathway” that glyphosate disrupts, causing shikimate to accumulate. Plants susceptible to glyphosate will have high levels of shikimate, while resistant plants will not, it said.
Although there are existing methods for detecting shikimate, they require sophisticated laboratory equipment, such as spectrophotometers that can measure ultraviolet light. USDA says test results can take weeks.
As part of his work with Monsanto, Shaner is growing glyphosate-resistant and glyphosate-susceptible crops and weeds in a greenhouse. He sprays some of those plants with glyphosate and places leaves from others in glyphosate solutions and then determines the levels and rates of shikimate accumulation. The goal is to evaluate different methods for assessing shikimate levels and to determine the most effective way for growers to collect plant material for testing with Monsanto’s system. The test kit’s design has yet to be determined.
Read the complete story here.
Get The Newsletter Today!
