Molecular characterization of the brassinosteroid-deficient lkb mutant in pea

Plant Mol Biol. 2001 Nov;47(4):491-8. doi: 10.1023/a:1011894812794.

Abstract

The brassinosteriod-deficient lkb mutant of garden pea (Pisum sativum L.) is characterized by an erectoides phenotype (reduced internode length, thickened stems, epinastic leaves), which is rescued by application of exogenous brassinolide. We show that the LKB gene is the Arabidopsis DIMINUTO/DWARF-1 (DIM/DWF1) homologue of pea. The DIM/DWF1 homologue from lkb plants contains a mutation that may result in reduced enzyme function, thus resulting in the previously shown accumulation of 24-methylenecholesterol and a deficiency of its hydrogenated product, campesterol. This ultimately leads to a deficiency of the biologically active brassionolide. The mutation in the lkb sequence cosegregates with the lkb phenotype. Northern analyis of the LKB gene revealed that the gene is ubiquitously expressed around the plant and that there is no evidence for negative feedback regulation of the gene.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis Proteins*
  • Blotting, Northern
  • Brassinosteroids
  • Cholestanols / metabolism*
  • Gene Expression Regulation, Plant
  • Genotype
  • Molecular Sequence Data
  • Mutation
  • Peas / genetics*
  • Peas / growth & development
  • Peas / metabolism
  • Phenotype
  • Phytosterols / metabolism*
  • Plant Development
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants / genetics
  • RNA, Plant / genetics
  • RNA, Plant / metabolism
  • Sequence Homology, Amino Acid
  • Steroids, Heterocyclic / metabolism*

Substances

  • Arabidopsis Proteins
  • Brassinosteroids
  • Cholestanols
  • DIM1 protein, Arabidopsis
  • Phytosterols
  • Plant Proteins
  • RNA, Plant
  • Steroids, Heterocyclic
  • brassinolide