Abstract: The present invention relates to a peptide of the formula: wherein R1 and R2 are the same or different and each represents SO3H or H; X represents an ?-amino acid or a single bond; Z1 and Z2 are the same or different and each represents an ?-amino acid; and Y represents OH or NH2. This peptide has plant growth factor properties.

Abstract: This invention provides a novel promoter derived from gene of phytosulfokine precursor derived from rice. The novel promoter of this invention can enhance expression of an exogenous structural gene with higher potency compared with conventional cauliflower mozaic virus 35S promoter.

Abstract: A phytosulfokine (PSK) receptor protein selected from the groups consisting of: (a) a protein comprising an amino acid sequence of SEQ ID No: 2, and (b) a protein comprising an amino acid sequence of SEQ ID No: 2, wherein one or a few amino acids are deleted, substituted and/or added and which is capable of responding to phytosulfokine (PSK) that is a plant cell growth factor.

Abstract: The present invention relates to a peptide of the formula: 1

Abstract: For the purpose to promote proliferation of a plant cell, a novel gene is provided by this invention. This invention provides a precursor polypeptide of phytosulfokine that enhances proliferation of a plant cell derived from Arabidopsis thaliana, named AtPSK2 polypeptide. This invention further provides AtPSK2 gene that encodes the AtPSK2 polypeptide. Moreover, this invention provides another precursor polypeptide of phytosulfokine that enhances proliferation of a plant cell derived from Arabidopsis thaliana, named AtPSKL polypeptide. This invention further provides AtPSKL gene that encodes the AtPSKL polypeptide. Proliferation of a plant cell can be achieved by incorporation of the gene according to this invention.

Abstract: The present invention relates to a peptide of the formula: wherein R1 and R2 are the same or different and each represents SO3H or H; X represents an &agr;-amino acid or a single bond; Z1 and Z2 are the same or different and each represents an &agr;-amino acid; and Y represents OH or NH2. This peptide has plant growth factor properties.

Abstract: This invention provides a novel promoter derived from gene of phytosulfokine precursor derived from rice.

Abstract: For the purpose of providing a technique available for the production of a transgenic plant, a method to promote the proliferation of a plant cell is developed. This invention provides an amino acid sequence of precursor polypeptide of phytosulfokine (preprophytosulfokine), a growth factor of plant origin, and a base sequence encoding the phytosulfokine precursor polypeptide. Incorporation of the gene encoding the phytosulfokine precursor polypeptide enables the promotion of plant cell proliferation.

Abstract: The present invention relates to a peptide of the formula: ##STR1## wherein both of R.sup.1 and R.sup.2 represent SO.sub.3 H, or either of R.sup.1 or R.sup.2 represents SO.sub.3 H and the rest represents H; Z represents an .alpha.-amino acid residue; X represents H or an acyl; and Y represents OH, C.sub.1-6 alkoxy or NH.sub.2, and to a plant growth promoter comprising the peptide.

Abstract: The present invention relates to a peptide of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each represents SO.sub.3 H or H; X represents an .alpha.-amino acid or a single bond; Z.sup.1 and Z.sup.2 are the same or different and each represents an .alpha.-amino acid; and Y represents OH or NH.sub.2. This peptide has plant growth factor properties.