64 results about "Acetohydroxyacid synthase" patented technology

Rice plants are disclosed with two separate, but synergistic mechanisms for resistance to herbicides that normally inhibit a plant's acetohydroxyacid synthase (AHAS) enzyme. The herbicide resistance of plants with both resistance mechanisms is substantially greater than one would expect from a simple combination of the two types of resistance. The first of the two resistance mechanisms is a metabolic pathway that is not fully understood, but that does not itself involve a mutant AHAS enzyme. The second resistance mechanism is a mutant AHAS enzyme, an enzyme that shows direct resistance to levels of herbicide that normally inhibit the enzyme, in both in vivo and in vitro assays. Besides controlling red rice, many AHAS-inhibiting herbicides also effectively control other weeds that are common in rice fields. Several of these herbicides have residual activity, so that a treatment controls both existing weeds as well as weeds that sprout later. No herbicide currently available for use on rice has residual activity against a broad spectrum of weeds including red rice. With effective residual activity against red rice and other weeds, rice producers now have a weed control system superior to those currently used.

This invention is directed to a screening method for the selection of mutations which confer acetohydroxyacid synthase (AHAS) inhibiting herbicide resistance to wheat. After mutagenesis of wheat seeds, the seeds are soaked in an AHAS inhibiting herbicide-containing solution containing a particular class of AHAS inhibiting herbicide. After planting, the soil containing the seeds is sprayed with an AHAS inhibiting herbicide of the same class as that used in the seed soak step prior to the emergence of the seedlings from the soil. Those wheat seedlings which emerge and are normal in appearance demonstrate resistance to the class of AHAS inhibiting herbicides used in the seed soak and spraying steps. This invention is also directed to the wheat selections and seeds identified by the screening method.

The invention relates to a genetically engineered bacterium for producing alpha-ketobutyric acid as well as a construction method and application of the genetically engineered bacterium, belonging to the technical field of biology. The strain is relatively high in production efficiency when used for producing alpha-ketobutyric acid through fermentation. The genetically engineered bacterium is obtained through carrying out genetic engineering modification on Escherichia coli MG1655; the genetic engineering modification is realized by knocking out a large-subunit encoding gene ilvB of acetohydroxyacid synthase I, a large-subunit encoding gene ilvI of acetohydroxyacid synthase III and a threonine operon leading peptide encoding gene thrL in an over-expressive threonine dehydratase encoding gene ilvA. When the bacterium is used for producing alpha-ketobutyric acid by using a fermentation method, defects such as complex reaction conditions, high energy consumption, serious pollution or high production cost, serious pollution and the like existing in a chemical synthesis method, an enzyme method or a microbial conversion method can be overcome; after the bacterium is fermented for 20-24h, the yield of alpha-ketobutyric acid is up to 8.5-15.7g / L; aerobic fermentation is adopted in a fermentation process; the bacterium is rapid in growth, short in fermentation period and high in acid production rate; any reports for producing alpha-ketobutyric acid by using a direct fermentation method are not found at present.

The invention provides a method for preparing AHAS (Acetohydroxyacid Synthase) which has good purity and high activity and can exist stably. The method comprises the following steps: upstream and downstream primers are designed according to a gene sequence of a colon bacillus AHAS catalytic subunit, wherein the designed upstream primer carries an Xho I enzyme digestion site and the downstream primer carries a BamHI enzyme digestion site; a colon bacillus BL21 strain genomic DNA (Deoxyribonucleic Acid) is used as a template and a target segment ahas is obtained by a PCR (Polymerase Chain Reaction) amplification technology; the target segment ahas is connected onto an expression carrier PGEX-AT-1 to obtain a recombinant plasmid PGEX-4T-1-ahas; inducible expression is realized in a prokaryotic expression system; an expressed enzyme is purified by agarose gel resin modified by glutathione sulfur transferase (GST) so as to obtain the acetohydroxyacid synthase with good activity.

The present invention provides novel methods for making wheat plants with increased grain protein content. The methods involve introducing a gene encoding herbicide-resistant, wheat acetohydroxyacid synthase large subunit (AHASL) protein. The invention further provides wheat plants that produce high protein grain and human and animal food products derived thereof.