Multicellular living organisms and unmodified parts thereof and – Method of introducing a polynucleotide molecule into or...
Reexamination Certificate
1999-02-18
2001-06-12
Benzion, Gary (Department: 1638)
Multicellular living organisms and unmodified parts thereof and
Method of introducing a polynucleotide molecule into or...
C435S320100, C435S410000, C435S418000, C435S468000, C435S471000, C536S023100, C536S023600, C536S023700, C800S300000
Reexamination Certificate
active
06245968
ABSTRACT:
The present invention relates to a nucleic acid sequence encoding a mutated hydroxyphenylpyruvate dioxygenase (HPPD), to a chimeric gene which comprises this sequence as the coding sequence, and to its use for isolating plants which are resistant to certain herbicides. The invention further relates to plants which contain the nucleic acid of the invention and which may be herbicide resistant, and to methods of growing these plants.
BACKGROUND OF THE INVENTION
The hydroxyphenylpyruvate dioxygenases are enzymes which catalyse the reaction in which para-hydroxyphenylpyruvate (HPP) is transformed into homogentisate. This reaction takes place in the presence of iron (Fe2+) and in the presence of oxygen (Crouch, N. P. et al., Tetrahedron, 53, 20, 6993-7010, 1997). It may be hypothesized that the HPPDs contain an active site which is capable of catalysing this reaction, in which iron, the substrate and the molecule of oxygen link together, although such an active site has not so far been described.
Some molecules which inhibit this enzyme, and which bind to the enzyme in order to inhibit transformation of the HPP into homogentisate, are also known. Some of these molecules have been used as herbicides since inhibition of the reaction in plants leads to whitening of the leaves of the treated plants and to the death of the said plants (Pallett, K. E. et al. 1997 Pestic. Sci. 50 83-84). The herbicides for which HPPD is the target, and which are described in the state of the art, are, in particular, isoxazoles (EP418175, EP470856, EP487352, EP527036, EP560482, EP682659, U.S. Pat. No. 5,424,276), in particular isoxaflutole, which is a selective herbicide for maize, diketonitriles (EP496630, EP496631), in particular 2-cyano-3-cyclopropyl-1-(2-SO2CH3-4-CF3 phenyl)propane-1,3-dione and 2-cyano-3-cyclopropyl-1-(2-SO2CH3-4-2,3Cl2phenyl)propane-1,3-dione, triketones (EP625505, EP625508, U.S. Pat. No. 5,506,195), in particular sulcotrione, or else pyrazolinates.
Three main strategies are available for making plants tolerant to herbicides, i.e. (1) detoxifying the herbicide with an enzyme which transforms the herbicide, or its active metabolite, into non-toxic products, such as, for example, the enzymes for tolerance to bromoxynil or to basta (EP242236, EP337899); (2) mutating the target enzyme into a functional enzyme which is less sensitive to the herbicide, or to its active metabolite, such as, for example, the enzymes for tolerance to glyphosate (EP293356, Padgette S. R. etal., J.Biol. Chem., 266, 33, 1991); or (3) overexpressing the sensitive enzyme so as to produce quantities of the target enzyme in the plant which are sufficient in relation to the herbicide, in view of the kinetic constants of this enzyme, so as to have enough of the functional enzyme available despite the presence of its inhibitor.
It is this third strategy which was described for successfully obtaining plants which were tolerant to HPPD inhibitors (WO96/38567), with it being understood that this was the first time that a strategy of simply overexpressing the (non-mutated) sensitive target enzyme was successfully used for conferring on plants agricultural level tolerance to a herbicide.
Despite the success obtained with this strategy of simply overexpressing the target enzyme, it is still necessary to improve the system of tolerance to HPPD inhibitors in order to obtain a tolerance whatever the conditions under which the tolerant plants are cultivated, or the commercial doses at which the herbicides are applied in the fields, may be.
REFERENCES:
patent: WO 96/38567 (1996-12-01), None
patent: WO97/27285 (1997-07-01), None
FEBS Letters, 1996, pp. 269-272 “The C-terminal of rat 4-hydroxyphenylpyruvate . . . Enzyme Activity”, Lee et al.
Biochemical Journal, 1997, pp. 761-769, “Subcellular localization and purificaiton . . . corresponding cDNA”, Garcia et al.
Journal of Biological Chemistry, 1991, vol. 266, pp. 22364-22369, “Site-directed Mutageneises of a Conserved Region . . . Synthase Active Site”, Padgette et al.
Boudec Philippe
Bourdon Hélène
Dumas Florence
Rodgers Matthew
Sailland Alain
Aventis Cropscience S.A.
Benzion Gary
Connolly Bove & Lodge & Hutz LLP
Mehta Ashwin
LandOfFree
Mutated hydroxyphenylpyruvate dioxygenase, DNA sequence and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mutated hydroxyphenylpyruvate dioxygenase, DNA sequence and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mutated hydroxyphenylpyruvate dioxygenase, DNA sequence and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2518972