Skip to main content
PMC home page
The Plant Cell logoLink to The Plant Cell
. 1995 Jan;7(1):75–84. doi: 10.1105/tpc.7.1.75

Cloning and characterization of the maize An1 gene.

R J Bensen 1, G S Johal 1, V C Crane 1, J T Tossberg 1, P S Schnable 1, R B Meeley 1, S P Briggs 1
PMCID: PMC160766  PMID: 7696880

Abstract

The Anther ear1 (An1) gene product is involved in the synthesis of ent-kaurene, the first tetracyclic intermediate in the gibberellin (GA) biosynthetic pathway. Mutations causing the loss of An1 function result in a GA-responsive phenotype that includes reduced plant height, delayed maturity, and development of perfect flowers on normally pistillate ears. The an1::Mu2-891339 allele was recovered from a Mutator (Mu) F2 family. Using Mu elements as molecular probes, an An1-containing restriction fragment was identified and cloned. The identity of the cloned gene as An1 was confirmed by using a reverse genetics screen for maize families that contain a Mu element inserted into the cloned gene and then by demonstrating that the insertion causes an an1 phenotype. The predicted amino acid sequence of the An1 cDNA shares homology with plant cyclases and contains a basic N-terminal sequence that may target the An1 gene product to the chloroplast. The sequence is consistent with the predicted subcellular localization of AN1 in the chloroplast and with its biochemical role in the cyclization of geranylgeranyl pyrophosphate, a 20-carbon isoprenoid, to ent-kaurene. The semidwarfed stature of an1 mutants is in contrast with the more severely dwarfed stature of GA-responsive mutants at other loci in maize and may be caused by redundancy in this step of the GA biosynthetic pathway. DNA gel blot analysis indicated that An1 is a single-copy gene that lies entirely within the deletion of the an1-bz2-6923 mutant. However, homozygous deletion mutants accumulated ent-kaurene to 20% of the wild-type level, suggesting that the function of An1 is supplemented by an additional activity.

Full Text

The Full Text of this article is available as a PDF (2.5 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Chandler V. L., Walbot V. DNA modification of a maize transposable element correlates with loss of activity. Proc Natl Acad Sci U S A. 1986 Mar;83(6):1767–1771. doi: 10.1073/pnas.83.6.1767. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987 Apr;162(1):156–159. doi: 10.1006/abio.1987.9999. [DOI] [PubMed] [Google Scholar]
  3. Colby S. M., Alonso W. R., Katahira E. J., McGarvey D. J., Croteau R. 4S-limonene synthase from the oil glands of spearmint (Mentha spicata). cDNA isolation, characterization, and bacterial expression of the catalytically active monoterpene cyclase. J Biol Chem. 1993 Nov 5;268(31):23016–23024. [PubMed] [Google Scholar]
  4. Duncan J. D., West C. A. Properties of Kaurene Synthetase from Marah macrocarpus Endosperm: Evidence for the Participation of Separate but Interacting Enzymes. Plant Physiol. 1981 Nov;68(5):1128–1134. doi: 10.1104/pp.68.5.1128. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Emerson R A, Emerson S H. Genetic Interrelations of Two Andromonoecious Types of Maize, Dwarf and Anther Ear. Genetics. 1922 May;7(3):203–236. doi: 10.1093/genetics/7.3.203. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Johal G. S., Briggs S. P. Reductase activity encoded by the HM1 disease resistance gene in maize. Science. 1992 Nov 6;258(5084):985–987. doi: 10.1126/science.1359642. [DOI] [PubMed] [Google Scholar]
  7. Jones D F. Unisexual Maize Plants and Their Bearing on Sex Differentiation in Other Plants and in Animals. Genetics. 1934 Nov;19(6):552–567. doi: 10.1093/genetics/19.6.552. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Math S. K., Hearst J. E., Poulter C. D. The crtE gene in Erwinia herbicola encodes geranylgeranyl diphosphate synthase. Proc Natl Acad Sci U S A. 1992 Aug 1;89(15):6761–6764. doi: 10.1073/pnas.89.15.6761. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Mau C. J., West C. A. Cloning of casbene synthase cDNA: evidence for conserved structural features among terpenoid cyclases in plants. Proc Natl Acad Sci U S A. 1994 Aug 30;91(18):8497–8501. doi: 10.1073/pnas.91.18.8497. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Shechter I., West C. A. Biosynthesis of gibberellins. IV. Biosynthesis of cyclic diterpenes from trans-geranylgeranyl pyrophosphate. J Biol Chem. 1969 Jun 25;244(12):3200–3209. [PubMed] [Google Scholar]
  11. Simcox P. D., Dennis D. T., West C. A. Kaurene synthetase from plastids of developing plant tissues. Biochem Biophys Res Commun. 1975 Sep 2;66(1):166–172. doi: 10.1016/s0006-291x(75)80309-3. [DOI] [PubMed] [Google Scholar]
  12. Sun Tp., Goodman H. M., Ausubel F. M. Cloning the Arabidopsis GA1 Locus by Genomic Subtraction. Plant Cell. 1992 Feb;4(2):119–128. doi: 10.1105/tpc.4.2.119. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Wadsworth G. J., Marmaras S. M., Matthews B. F. Isolation and characterization of a soybean cDNA clone encoding the plastid form of aspartate aminotransferase. Plant Mol Biol. 1993 Mar;21(6):993–1009. doi: 10.1007/BF00023598. [DOI] [PubMed] [Google Scholar]
  14. Zeevaart J. A., Gage D. A. ent-kaurene biosynthesis is enhanced by long photoperiods in the long-day plants Spinacia oleracea L. and Agrostemma githago L. Plant Physiol. 1993 Jan;101(1):25–29. doi: 10.1104/pp.101.1.25. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Plant Cell are provided here courtesy of Oxford University Press

RESOURCES