title: Cloning and expression analysis of DNA sequences for the major latex protein of opium poppy.
abstract: Opium-poppy (Papaver somniferum L.) latex contains a group of very abundant, laticifer-specific peptides called the major latex proteins (MLPs). We determined a partial amino-acid sequence of an MLP cyanogen bromide peptide fragment that was used to design an MLP oligonucleotide primer. An MLP-specific DNA probe was then generated by polymerase chain reaction (PCR) of first-strand complementary DNA (cDNA) templates primed with the MLP oligonucleotide and oligodeoxythymidylic acid. This DNA fragment, called MLP-PCR, and two partial MLP cDNAs isolated with it, all contain open reading frames matching the known MLP amino-acid sequence. RNA gel blots of latex, tissue cultures, and the major organs of mature plants of opium poppy show that MLP is coded for by an 860-nucleotide mRNA and that this accumulates exclusively in laticifers.
authors.affiliation: Department of Biology, Texas A & M University, 77843-3258, College Station, TX, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Nessler
authors.forename: R A
authors.initials: RA
authors.lastname: Vonder Haar