Planta

, Volume 200, Issue 2, pp 159–166

Feed-back regulation of gibberellin biosynthesis and gene expression in Pisum sativum L.

  • David N. Martin
  • William M. Proebsting
  • T. Dawn Parks
  • William G. Dougherty
  • Theodor Lange
  • Mervyn J. Lewis
  • Paul Gaskin
  • Peter Hedden
Article

DOI: 10.1007/BF00208304

Cite this article as:
Martin, D.N., Proebsting, W.M., Parks, T.D. et al. Planta (1996) 200: 159. doi:10.1007/BF00208304

Abstract

Treatment of tall and dwarf (3β-hydroxylase impaired) genotypes of pea (Pisum sativum L.) with the synthetic, highly active gibberellin (GA), 2,2-dimethyl GA4, reduced the shoot contents of C19-GAs, including GA1, and increased the concentration of the C20-GA, GA19. In shoots of the slender (la crys) mutant, the content of C19-GAs was lower and GA19 content was higher than in those of the tall line. Metabolism of GA19 and GA20 in leaves of a severe (na) GA-deficient dwarf mutant was reduced by GA treatment. The results suggest feedback regulation of the 20-oxidation and 3β-hydroxylation reactions. Feed-back regulation of GA 20-oxidation was studied further using a cloned GA 20-oxidase cDNA from pea. The cDNA, Ps074, was isolated using polymerase chain reaction with degenerate oligonucleotide primers based on pumpkin and Arabidopsis 20-oxidase sequences. After expression of this cDNA clone in Escherichia coli, the product oxidized GA12 to GA15, GA24 and the C19-GA, GA9, which was the major product. The 13-hydroxylated substrate GA53 was similarly oxidized, but less effectively than GA12, giving mainly GA44 with low yields of GA19 and GA20. Ps074 hybridized to polyadenylated RNA from expanding shoots of pea. Amounts of this transcript were less in the slender genotype than in the tall line and were reduced in GA-deficient genotypes by treatment with GA3, suggesting that there is feed-back regulation of GA 20-oxidase gene expression.

Key words

Gibberellin biosynthesis (regulation)Gibberellin 20-oxidase (cDNA cloning)Pisum

Abbreviations

GA

gibberellin

GC-SIM

gas chromatography-single ion monitoring

IPTG

isopropyl-β-d-thiogalactoside

PCR

polymerase chain reaction

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • David N. Martin
    • 1
  • William M. Proebsting
    • 1
  • T. Dawn Parks
    • 2
  • William G. Dougherty
    • 2
  • Theodor Lange
    • 3
  • Mervyn J. Lewis
    • 4
  • Paul Gaskin
    • 4
  • Peter Hedden
    • 4
  1. 1.Department of Horticulture and Center for Gene Research and BiotechnologyOregon State UniversityCorvallisUSA
  2. 2.Department of Microbiology and Center for Gene Research and BiotechnologyOregon State UniversityCorvallisUSA
  3. 3.Pflanzenphysiologisches Institut und Botanischer Garten der Universität GöttingenGöttingenGermany
  4. 4.IACR-Long Ashton Research Station, Department of Agricultural SciencesUniversity of BristolBristolUK