Table of Contents
Which is herbicide resistant gene?
A gene which confers resistance to the herbicide bialaphos (bar) has been characterized. The bar gene was originally cloned from Streptomyces hygroscopicus, an organism which produces the tripeptide bialaphos as a secondary metabolite.
What does glyphosate resistance mean?
Several known glyphosate-resistant weeds require eight to 10 times more glyphosate to be controlled than the normal, sensitive biotypes. This level of resistance means that labeled glyphosate rates will not control these weeds, and that making applications at labeled rates probably will not prevent resistance.
How are plants resistant to glyphosate?
There are several ways by which crops can be modified to be glyphosate-tolerant. One strategy is to incorporate a soil bacterium gene that produces a glyphosate tolerant form of EPSPS. Another way is to incorporate a different soil bacterium gene that produces a glyphosate degrading enzyme.
What does the CP4 Epsps gene do?
Roundup Ready™ varieties contain a gene derived from a naturally-occurring soil microbe, Agrobacterium sp. strain CP4 that encodes the cp4 epsps gene that confers tolerance to glyphosate.
What is herbicide-resistant plants?
Herbicide resistance is the inherited ability of an individual plant to survive a herbicide application that would kill a normal population of the same species. Herbicide resistance does not equate to poor performance of a herbicide.
What is herbicide resistance in transgenic plants?
The term ‘herbicide-resistant crop’ (HRC) describes crops made resistant to herbicides by either transgene technology or by selection in cell or tissue culture for mutations that confer herbicide resistance. HRCs are also referred to as herbicide-tolerant crops.
How do you stop herbicide resistance from evolving?
Prevention and management strategies
- Only use herbicides when necessary.
- Rotate herbicides (sites of action)
- Apply herbicides that include multiple sites of action.
- Rotate crops, particularly those with different life cycles.
- Avoid more than two consecutive herbicide applications with herbicide-resistant crops.
Why are glyphosate resistant crops considered safer than other genetically modified organisms?
The protein is just slightly changed so that it is no longer affected by glyphosate. This means that herbicide-resistant plants have very little genetic modification, and many people believe this makes them safer than other GMOs. Glyphosate-resistant crops have been very commercially successful.
Where does CP4 Epsps come from?
The cp4 epsps gene is derived from a bacterium common in the soil, Agrobacterium sp. strain CP4, which codifies the expression of protein EPSPS naturally tolerant to glyphosate.
Which approach will be the best for development of glyphosate resistant transgenic plant and why?
However, when glyphosate kills weeds in a field, it also damages the crops. Therefore, efforts to cultivate and promote glyphosate-resistant cotton varieties via genetic engineering technology are the most effective approaches for controlling glyphosate weeds in cotton fields.
How do you deal with herbicide resistance?
What is the molecular basis for crop resistance to glyphosate?
Once incorporated into the plant genome, the gene product, CP4 EPSP synthase, confers crop resistance to glyphosate. Although widely used, the molecular basis for this glyphosate-resistance has remained obscure.
How many copies of the EPSPS gene are in glyphosate resistance?
One of the increasingly widespread mechanisms of resistance to the herbicide glyphosate is copy number variation (CNV) of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene. EPSPS gene duplication has been reported in 8 weed species, ranging from 3 to 5 extra copies to more than 150 extra copies.
Is there positive selection for glyphosate resistance?
Of particular relevance when considering glyphosate resistance mechanisms, examples have been reported of positive selection for gene dosage, leading to adaptive gene duplication in response to stressful environmental conditions. 48
Is target-gene duplication a common glyphosate resistance mechanism?
Today, target-gene duplication is a common glyphosate resistance mechanism and could become a fundamental process for developing any resistance trait. Based on competition and substrate selectivity studies in several species, rapid vacuole sequestration of glyphosate occurs via a transporter mechanism.