Abstract: This invention provides plant arabinogalactan proteins (AGPs) and their genes. AGPs were isolated from Nicotiana alata, Nicotiana plumbaginafolia, and Pyrus communis. Amino acid sequences of isolated AGP peptide fragments are presented. Isolated AGP fragments were used to synthesize oligonucleotide probes to prepare oligonucleotide primers for PCR or prepare RNA probes to screen cDNA libraries of N. alata, N. plumbaginafolia, and P. communis. cDNA clones encoding amino acid sequences of isolated AGP fragments were isolated. The invention presents for the first time an intact AGP amino acid sequence derived from a corresponding AGP gene. The instant invention further provides methods useful in obtaining AGP genes encoding an AGP peptide comprising a specific isolated hydroxyproline-rich (OAST-rich) sequence or a specific isolated hydroxyproline-poor sequence.

Abstract: This invention provides plant arabinogalactan proteins (AGPs) and their genes. AGPs were isolated from Nicotiana alata, Nicotiana plumbaginafolia, and Pyrus communis. Amino acid sequences of isolated AGP peptide fragments are presented. Isolated AGP fragments were used to synthesize oligonucleotide probes to prepare oligonucleotide primers for PCR or prepare RNA probes to screen cDNA libraries of N. alata, N. plumbaginafolia, and P. communis. cDNA clones encoding amino acid sequences of isolated AGP fragments were isolated. The invention presents for the first time an intact AGP amino acid sequence derived from a corresponding AGP gene. The instant invention further provides methods useful in obtaining AGP genes encoding an AGP peptide comprising a specific isolated hydroxyproline-rich (OAST-rich) sequence or a specific isolated hydroxyproline-poor sequence.

Abstract: DNA sequence of S-genes which encode S-proteins and control the self-incompatibility reaction in gametophytic self-incompatible plants have been identified. The DNA sequence encoding several S-proteins of N. alata and their attendant signal sequences are specifically provided. Regulatory sequences which direct expression of the S-genes in reproduction tissue of self-incompatible plants have also been identified. A method for the identification and isolation of cDNA and genomic DNA coding sequences of the S-genes is described.

Abstract: A class of proteins associated with self-incompatibility alleles of plants, preferably of gametophytic self-incompatibility type, are provided. These proteins inhibit pollen tube growth in a plant style having the associated self-incompatibility allele, and have defined amino acid homologies and cross-reactivities.