Abstract: A method is provided for increasing the level of free L-lysine in a plant comprising: (a) introducing a foreign gene into the cells of a plant tissue source; and (b) expressing said foreign gene in said cells, wherein a first DNA sequence of said gene encodes dihydrodipicolinic acid synthase (DHDPS) which is substantially resistant to feedback inhibition by endogenously-produced free L-lysine.

Abstract: Methods are provided for stabilization and purification of proteins produced in host cell systems. The methods provide for significant stabilization of any unfused non-bacterial protein that is produced in the same host cell that is producing an aggregate-forming fusion protein or any aggregate-forming protein.

Abstract: Methods and compositions for the insertion and molecular cloning of RNA in DNA cloning vectors are described. RNA molecules to be cloned are modified by the ligation of oligonucleotide linkers onto the termini of the RNA molecule using T4 RNA ligase. Such linkers may be composed of DNA, RNA, or mixtures of each and facilitate the insertion and ligation of the RNA species into a DNA cloning vector. The resulting recombinant vectors are used to transform host cells which provide for the generation of multiple DNA copies of the RNA molecule.

Abstract: This invention is direction 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 exzymes, 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.

Abstract: DNA cloning and expression vectors capable of replication in a microbial host comprising from upstream to downstream (a) at least one promoter; (b) a translation start codon; (c) a cloning segment which provides a means for inserting nucleic acid sequences and (d) a sequence coding for a detectable gene product, out of translational phase with the translation start codon but capable of being readjusted to the translational phase of said start codon by insertion into the cloning segment of nucleic acid sequences containing the proper number of nucleotides for readjustment, said gene product providing a means for detecting expression of inserted nucleic acid sequences.