Two soybean seed lipoxygenase nulls accumulate reduced levels of lipoxygenase transcripts

William G. Start, Yu Ma, Joseph C. Polacco, David F. Hildebrand, Greg A. Freyer, Mitchell Altschuler

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

Soybean (Glycine max L. [Merrill]) seed lipoxygenase cDNA clones were recovered from two cDNA libraries: a size-selected library in pBR322 and an expression library in pUC8. The pUC8 library was made with total poly(A)+ embryo RNA and was screened with antiserum to lipoxygenase-1, one of 3 seed lipoxygenase isozymes. Three lipoxygenase antigen-producing clones were identified: two with identical cDNA inserts of 977 nucleotides representing an open-reading frame and a third truncated clone bearing a 3′ end common to the longer clones. A long clone, pAL-134, was chosen for further study and was used to screen the size-selected cDNA library from which sixteen clones were identified. They fall into two homology classes represented by pLX-10 (ca. 1360 bp) and pLX-65 (2047 bp). The lipoxygenase expression clone pAL-134 hybridized much more strongly to pLX-65 than to pLX-10. pAL-134 and pLX-65 share 89% nucleotide homology and 75% deduced amino acid homology along their common sequence. Their deduced amino acid sequences each show 80% homology to sequences determined for isolated peptides of the lipoxygenase-1 isozyme. pAL-134 hybridizes poorly with a 3.8 kb RNA from LOX-1 null (lx1) embryos while pLX-65 hybridizes more strongly, but still to a lesser extent than its hybridization to standard embryo RNA or to RNA from embryos lacking lipoxygenase-2 (lx2) or lipoxygenase-3 (lx3) protein. The lx3 null lacks almost all embryo 3.8 kb RNA homologous to pLX-10. This hybridization pattern suggests that pLX-10 encodes LOX-3. Thus, the lx1 and lx3 genotypes accumulate little, if any, mRNA for the lipoxygenase-1 and lipoxygenase-3 isozymes, respectively.

Original languageEnglish
Pages (from-to)11-23
Number of pages13
JournalPlant Molecular Biology
Volume7
Issue number1
DOIs
StatePublished - Jan 1986

Bibliographical note

Funding Information:
The authors would like to extend their sincere appreciation to All Cosmos Industries Sdn. Bhd., PasirGudang, Johor, Malaysia, as well as the Deanship of Scientific Research at King Saud University for funding this work through research group project "RG-1435-047".

Keywords

  • Glycine max
  • cDNA
  • lipoxygenase
  • lipoxygenase-null
  • pUC8 expression vector
  • seed protein

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Genetics
  • Plant Science

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