Characterization and plant expression of glyphosate-tolerant enolpyruvylshikimate phosphate synthase

Abstract BACKGROUND: Glyphosate tolerance is a dominant trait in modern biotech crops. RESULTS: A gene encoding a glyphosate-tolerant EPSP synthase (aroA 1398 ) from bacterial strain ATX1398 was cloned and characterized. The protein is initiated at a GTG translational start codon to produce a protein that provides robust glyphosate resistance in Escherichia coli (Mig) Cast & Chalm. The aroA 1398 protein was expressed and purified from E. coli, and key kinetic values were determined (K i = 161 µM; K m (PEP) = 11.3 µM; k cat = 28.3 s −1 ). The full-length enzyme is 800-fold more resistant to glyphosate than the maize EPSP synthase while retaining high affinity for the substrate phosphoenol pyruvate. To evaluate further the potential of aroA 1398 , transgenic maize events expressing the aroA 1398 protein were generated. T 0 plants were screened for tolerance to glyphosate sprays at 1.3× commercial spray rates, and T 1 plants were selected that completely resisted glyphosate sprays at 1×, 2× and 4× recommended spray rates in field trials. CONCLUSION: These data suggest that aroA 1398 is a suitable candidate for conferring glyphosate tolerance in transgenic crop plants

A Bacillus thuringiensis Cry protein controls soybean cyst nematode in transgenic soybean plants

Genetic resistance to soybean cyst nematode (SCN) is beginning to decline. Here, the authors report that soybean lines expressing the Bacillus thuringiensis protein Cy14Ab have significant levels of protection from SCN in both greenhouse and field trials

A New Prepayment Model (with Default): An Occupation-time Derivative Approach

Prepayment, Fixed-rate mortgages, Option-pricing theory, Occupation-time derivatives, Parisian options,

An Improved Fixed-Rate Mortgage Valuation Methodology with Interacting Prepayment and Default Options

Fixed-rate mortgages, Option pricing theory, Perturbation theory, Prepayment, Default,