Roundup Ready™ alfalfa

Medicago sativa, also known as alfalfa or lucerne, is a perennial herbaceous legume. It contains the 5-enolpyruvylshikimate-3-phosphate synthase gene from Agrobacterium tumefaciens strain CP4 to confer tolerance to glyphosate, the active ingredient in the herbicide Roundup®, and allows the use of the chemical as a weed control option. Due to the inclusion of the Figwort Mosaic Virus 356S promoter, herbicide tolerance is constitutive and allows for weed control at anytime (early, pre-plant, pre-emergence, and post-emergence).

Proprietary alfalfa clone 'R2336.'

PV-MSHT4

Transcription of the herbicide tolerance gene, 5-enolpyruvylshikimate-3-phosphate synthase (cp4-epsps) from Agrobacterium tumefaciens, is under control of the Figwort Mosaic Virus 35S promoter and the Pisum sativum Rubisco small subunit terminator. The transcript also contains the Petunia hybrid heat shock protein 70 5'untranslated region for enhanced translation and the Arabidopsis thaliana chloroplast transit peptide 2 for targeting the translated polypeptide to the chloroplast. Transcript level are expected to be elevated due to the constitutive, viral promoter and the protein sequestered in the chloroplasts. 

Note:
- A single T-DNA integration site was detected by Southern blot analysis
- The vector backbone was not integrated into the J101 genome
- Sequencing analysis confirmed the sequence of the genetic elements of the cp4-epsps- cassette

Lucerne is a forage crop for feeding to dairy cattle and horses, as well as a valuable feed crop for beef cattle, sheep and other livestock. It is a nitrogen-fixing crop due to its symbiosis with Rhizobium meliloti and has the ability to improve soil fertility.

The EPSPS gene is present in animals, fungi, bacteria and plants and is responsible for aromatic amino acid biosynthesis. Glycophosate binds to the plant version of the EPSPS gene and blocks enzymatic biosynthesis of the aromatic amino acids and leads to the death of the plant. The introduced gene was isolated from the common soil bacterium Agrobacterium tumefaciens strain CP4 and the form of EPSPS enzyme produced by this gene has a low affinity for glycophosate, thus allowing for the continued biosynthesis of aromatic amino acids.