Tryptophan overproducer mutants of cereal crops

• US 4,581,847 A
• Filed: 09/04/1984
• Issued: 04/15/1986
• Est. Priority Date: 09/04/1984
• Status: Expired due to Term

• Current Assignee: DEKALB Genetics Corp. (Bayer AG)
• Original Assignee: Molecular Genetics Research and Development Limited Partnership
• Inventors: Anderson, Paul C., Barker, Melanie, Hibberd, Kenneth A.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/647,008
• Time in Patent Office: 588 Days
• Field of Search: 47/58
• US Class Current: 800/268
• CPC Class Codes: A01H 5/10 Seeds
• CPC Class Codes: A01H 6/4684 Zea mays [maize]
• CPC Class Codes: C12N 15/01 Preparation of mutants without inserting foreign genetic material therein; Screening processes therefor
• CPC Class Codes: C12N 15/8254 Tryptophan or lysine
• CPC Class Codes: C12N 5/04 Plant cells or tissues culture media C12N5/0025
• CPC Class Codes: C12N 9/88 Lyases (4.)

Abstract

This invention is directed to the production of novel plant genotypes or lines which produce increased free tryptophan levels and are resistant to inhibition by analogs which normally inhibit the activity of the enzyme anthranilate synthase before alteration. This invention further relates to genes encoding such enzymes, and to processes for utilizing these novel genes and enzymes. Further products of the invention include plants, plant tissues and seeds which exhibit resistance to such analogs and overproduce tryptophan resulting from expression of genes encoding analog resistant anthranilate synthase enzyme.

Claims

1. A maize seed having an endogenious free tryptophan content of at least about one-tenth milligram per gram dry seed weight and capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight.

2. The maize seed according to claim 1, having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight and capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight.

3. A tryptophan overproducing maize seed capable of germinating into a plant capable of expressing a gene coding for an anthranilate synthase which retains from about 60 to about 80 percent of its activity in the presence of 5-methyltryptophan at a concentration of about 10^-5 M, wherein the plant is capable of transmitting the gene encoding the anthranilate synthase to its progeny.

4. A tryptophan overproducing maize seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation, wherein the seed is capable of germinating into a plant capable of producing seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptopha,n, as measured after six days incubation.

5. A maize seed deposited with In Vitro International, Inc. and assigned IVI accession No. 10010.

6. A maize seed resulting from crossing C-28 with another maize line.

7. A hybrid maize seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight and capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight.

8. The hybrid mazie seed according to claim 7, having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight and capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight.

9. A tryptophan overproducing hybrid maize seed capable of germinating into a plant capable of expressing a gene coding for an anthranilate synthase which retains from about 60 to about 80 percent of its activity in the presence of 5-methyltryptophan at a concentration of about 10^-5 M, wherein the plant is capable of transmitting the gene encoding the anthranilate synthase to its progeny.

10. A tryptophan overproducing hybrid maize seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation, wherein the seed is capable of germinating into a plant capable of producing seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation.

11. A maize plant capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight, wherein the seed is capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight.

12. The maize plant according to claim 11, wherein the plant is capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight, wherein the seed is capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight.

13. A tryptophan overproducing maize plant capable of expressing a gene coding for an anthranilate synthase which retains from about 60 to about 80 percent of its activity in the presence of 5-methyltryptophan at a concentration of about 10^-5 M, wherein the plant is capable of transmitting the gene encoding the anthranilate synthase to its progeny.

14. A tryptophan overproducing maize plant capable of producing seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation, wherein the seed is capable of germinating into a plant capable of producing seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation.

15. A maize plant derived from seeds deposited with In Vitro International, Inc. and assigned IVI accession No. 10010.

16. A maize plant having an average endogenous free tryptophan content of at least about 0.04 milligrams per gram fresh weight.

17. The maize plant according to claim 16, having an average endogenous free tryptophan content of at least about one-tenth milligram per gram fresh weight.

18. A hybrid maize plant capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight, wherein the seed is capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight.

19. The hybrid maize plant according to claim 18, wherein the plant is capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight, wherein the seed is capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight.

20. A tryptophan overproducing hybrid maize plant capable of expressing a gene coding for an anthranilate synthase which retains from about 60 to about 80 percent of its activity in the presence of 5-methyltryptophan at a concentration of about 10^-5 M, wherein the plant is capable of transmitting the gene encoding the anthranilate synthase to its progeny.

21. A tryptophan overproducing hybrid maize plant capable of producing seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation, wherein the seed is capable of germinating into a plant capable of producing seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation.

22. A maize tissue culture capable of generating a plant capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight, wherein the seed is capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight.

23. The maize tissue culture according to claim 22, wherein the plant is capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight, wherein the seed is capable of germinating into a plant capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight.

24. A tryptophan overproducing maize tissue culture capable of generating a plant capable of expressing a gene coding for an anthranilate synthase which retains from about 60 to about 80 percent of its activity in the presence of 5-methyltryptophan at a concentration of about 10^-5 M, wherein the plant is capable of transmitting the gene encoding the anthranilate synthase to its progeny.

25. A tryptophan overproducing maize tissue culture capable of generating a plant capable of producing seed having an embryo capable of producing in the presence 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation, wherein the seed is capable of germinating into a plant capable of producing seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about 60 percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation.

26. A maize tissue culture derived from seeds deposited with In Vitro International, Inc. and assigned IVI accession No. 10010.

27. A maize tissue culture having an average endogenous free tryptophan content of at least about 0.78 milligrams per gram dry weight.

28. A method for producing a tryptophan overproducing maize plant, comprising the steps of:

(a) isolating an appropriate donor tissue from a maize plant and growing said tissue in an initiation/maintenance medium to initiate and maintain the growth of plant tissue cultures;

(b) growing said plant tissue cultures in the presence of a tryptophan analog at a level which inhibits from about 60% to about 80% of growth during the first four weeks;

(c) repeated subculturing the plant tissue cultures of step (b) in the presence of the tryptophan analog;

(d) identifying a stable analog resistant plant cell line from step (c) which grows at a rate comparable to that of a plant tissue culture grown in the absence of a tryptophan analog; and

(e) regenerating a maize plant from said stable analog resistant plant cell line.

29. A method for producing hybrid maize seed, comprising crossing a first maize line capable of producing seed having an endogenous free tryptophan content of at least about one-tenth milligram per gram dry seed weight, and another maize line.

30. A method for producing hybrid maize seed, comprising crossing a first maize line capable of producing seed having an endogenous free tryptophan content of at least about one milligram per gram dry seed weight, and another maize line.

31. A method for producing hybrid maize seed, comprising crossing a first maize line capable of expressing a gene coding for an anthranilate synthase which retains from about 60 to about 80 percent of its activity in the presence of 5-methyltryptophan at a concentration of about 10^-5 M, and another maize line.

32. A method for producing hybrid maize seed, comprising crossing a first maize line capable of producing seed having an embryo capable of producing in the presence of 5-methyltryptophan at a concentration of 10^-4 M roots of at least about percent of the length of roots produced in the absence of 5-methyltryptophan, as measured after six days incubation, and another maize line.