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. 1998 Feb;10(2):245–254. doi: 10.1105/tpc.10.2.245

Heterotrimeric G proteins are implicated in gibberellin induction of a-amylase gene expression in wild oat aleurone

HD Jones 1, SJ Smith 1, R Desikan 1, S Plakidou-Dymock 1, A Lovegrove 1, R Hooley 1
PMCID: PMC143985  PMID: 9490747

Abstract

The role of heterotrimeric G proteins in gibberellin (GA) induction of a-amylase gene expression was examined in wild oat aleurone protoplasts. Mas7, a cationic amphiphilic tetradecapeptide that stimulates GDP/GTP exchange by heterotrimeric G proteins, specifically induced alpha-amylase gene expression and enzyme secretion in a very similar manner to GA1. In addition, Mas7 stimulated expression of an alpha-Amy2/54:GUS promoter and reporter construct in transformed protoplasts. Both Mas7 and GA1 induction of alpha-amylase mRNA were insensitive to pertussis toxin. Hydrolysis-resistant nucleotides were introduced into aleurone protoplasts during transfection with reporter gene constructs. GDP-beta-S, which inhibits GDP/GTP exchange by heterotrimeric G proteins, completely prevented GA1 induction of alpha-Amy2/54:GUS expression, whereas GTP-gamma-S, which activates heterotrimeric G proteins, stimulated expression very slightly. Novel cDNA sequences from Galpha and Gbeta subunits were cloned from wild oat aleurone cells. By using RNA gel blot analysis, we found that the transcripts were expressed at a low level. Heterotrimeric G proteins have been implicated in several events during plant growth and development, and these data suggest that they may be involved in GA regulation of alpha-amylase gene expression in aleurone.

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Selected References

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  1. Beffa R., Szell M., Meuwly P., Pay A., Vögeli-Lange R., Métraux J. P., Neuhaus G., Meins F., Jr, Nagy F. Cholera toxin elevates pathogen resistance and induces pathogenesis-related gene expression in tobacco. EMBO J. 1995 Dec 1;14(23):5753–5761. doi: 10.1002/j.1460-2075.1995.tb00264.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bowler C., Neuhaus G., Yamagata H., Chua N. H. Cyclic GMP and calcium mediate phytochrome phototransduction. Cell. 1994 Apr 8;77(1):73–81. doi: 10.1016/0092-8674(94)90236-4. [DOI] [PubMed] [Google Scholar]
  3. Chen X., Chang M., Wang B., Wu B. Cloning of a Ca(2+)-ATPase gene and the role of cytosolic Ca2+ in the gibberellin-dependent signaling pathway in aleurone cells. Plant J. 1997 Mar;11(3):363–371. doi: 10.1046/j.1365-313x.1997.11030363.x. [DOI] [PubMed] [Google Scholar]
  4. Cho M. H., Tan Z., Erneux C., Shears S. B., Boss W. F. The effects of mastoparan on the carrot cell plasma membrane polyphosphoinositide phospholipase C. Plant Physiol. 1995 Mar;107(3):845–856. doi: 10.1104/pp.107.3.845. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Conklin B. R., Bourne H. R. Structural elements of G alpha subunits that interact with G beta gamma, receptors, and effectors. Cell. 1993 May 21;73(4):631–641. doi: 10.1016/0092-8674(93)90245-l. [DOI] [PubMed] [Google Scholar]
  6. Fairley-Grenot K., Assmann S. M. Evidence for G-Protein Regulation of Inward K+ Channel Current in Guard Cells of Fava Bean. Plant Cell. 1991 Sep;3(9):1037–1044. doi: 10.1105/tpc.3.9.1037. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gelli A., Higgins V. J., Blumwald E. Activation of Plant Plasma Membrane Ca2+-Permeable Channels by Race-Specific Fungal Elicitors. Plant Physiol. 1997 Jan;113(1):269–279. doi: 10.1104/pp.113.1.269. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Gilroy S., Jones R. L. Perception of Gibberellin and Abscisic Acid at the External Face of the Plasma Membrane of Barley (Hordeum vulgare L.) Aleurone Protoplasts. Plant Physiol. 1994 Apr;104(4):1185–1192. doi: 10.1104/pp.104.4.1185. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Gubler F., Kalla R., Roberts J. K., Jacobsen J. V. Gibberellin-regulated expression of a myb gene in barley aleurone cells: evidence for Myb transactivation of a high-pI alpha-amylase gene promoter. Plant Cell. 1995 Nov;7(11):1879–1891. doi: 10.1105/tpc.7.11.1879. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Helms J. B. Role of heterotrimeric GTP binding proteins in vesicular protein transport: indications for both classical and alternative G protein cycles. FEBS Lett. 1995 Aug 1;369(1):84–88. doi: 10.1016/0014-5793(95)00620-o. [DOI] [PubMed] [Google Scholar]
  11. Higashijima T., Burnier J., Ross E. M. Regulation of Gi and Go by mastoparan, related amphiphilic peptides, and hydrophobic amines. Mechanism and structural determinants of activity. J Biol Chem. 1990 Aug 25;265(24):14176–14186. [PubMed] [Google Scholar]
  12. Higashijima T., Uzu S., Nakajima T., Ross E. M. Mastoparan, a peptide toxin from wasp venom, mimics receptors by activating GTP-binding regulatory proteins (G proteins). J Biol Chem. 1988 May 15;263(14):6491–6494. [PubMed] [Google Scholar]
  13. Hooley R. Gibberellins: perception, transduction and responses. Plant Mol Biol. 1994 Dec;26(5):1529–1555. doi: 10.1007/BF00016489. [DOI] [PubMed] [Google Scholar]
  14. Huttly A. K., Baulcombe D. C. A wheat alpha-Amy2 promoter is regulated by gibberellin in transformed oat aleurone protoplasts. EMBO J. 1989 Jul;8(7):1907–1913. doi: 10.1002/j.1460-2075.1989.tb03593.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Ishikawa A., Tsubouchi H., Iwasaki Y., Asahi T. Molecular cloning and characterization of a cDNA for the alpha subunit of a G protein from rice. Plant Cell Physiol. 1995 Mar;36(2):353–359. doi: 10.1093/oxfordjournals.pcp.a078767. [DOI] [PubMed] [Google Scholar]
  16. Kim W. Y., Cheong N. E., Lee D. C., Je D. Y., Bahk J. D., Cho M. J., Lee S. Y. Cloning and sequencing analysis of a full-length cDNA encoding a G protein alpha subunit, SGA1, from soybean. Plant Physiol. 1995 Jul;108(3):1315–1316. doi: 10.1104/pp.108.3.1315. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Kuo A., Cappelluti S., Cervantes-Cervantes M., Rodriguez M., Bush D. S. Okadaic acid, a protein phosphatase inhibitor, blocks calcium changes, gene expression, and cell death induced by gibberellin in wheat aleurone cells. Plant Cell. 1996 Feb;8(2):259–269. doi: 10.1105/tpc.8.2.259. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Lee H. J., Tucker E. B., Crain R. C., Lee Y. Stomatal Opening Is Induced in Epidermal Peels of Commelina communis L. by GTP Analogs or Pertussis Toxin. Plant Physiol. 1993 May;102(1):95–100. doi: 10.1104/pp.102.1.95. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Legendre L., Heinstein P. F., Low P. S. Evidence for participation of GTP-binding proteins in elicitation of the rapid oxidative burst in cultured soybean cells. J Biol Chem. 1992 Oct 5;267(28):20140–20147. [PubMed] [Google Scholar]
  20. Li W., Assmann S. M. Characterization of a G-protein-regulated outward K+ current in mesophyll cells of vicia faba L. Proc Natl Acad Sci U S A. 1993 Jan 1;90(1):262–266. doi: 10.1073/pnas.90.1.262. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Ma H. GTP-binding proteins in plants: new members of an old family. Plant Mol Biol. 1994 Dec;26(5):1611–1636. doi: 10.1007/BF00016493. [DOI] [PubMed] [Google Scholar]
  22. Ma H., Yanofsky M. F., Huang H. Isolation and sequence analysis of TGA1 cDNAs encoding a tomato G protein alpha subunit. Gene. 1991 Nov 15;107(2):189–195. doi: 10.1016/0378-1119(91)90318-6. [DOI] [PubMed] [Google Scholar]
  23. Ma H., Yanofsky M. F., Meyerowitz E. M. Molecular cloning and characterization of GPA1, a G protein alpha subunit gene from Arabidopsis thaliana. Proc Natl Acad Sci U S A. 1990 May;87(10):3821–3825. doi: 10.1073/pnas.87.10.3821. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Neer E. J. Heterotrimeric G proteins: organizers of transmembrane signals. Cell. 1995 Jan 27;80(2):249–257. doi: 10.1016/0092-8674(95)90407-7. [DOI] [PubMed] [Google Scholar]
  25. Neuhaus G., Bowler C., Kern R., Chua N. H. Calcium/calmodulin-dependent and -independent phytochrome signal transduction pathways. Cell. 1993 Jun 4;73(5):937–952. doi: 10.1016/0092-8674(93)90272-r. [DOI] [PubMed] [Google Scholar]
  26. Penson S. P., Schuurink R. C., Fath A., Gubler F., Jacobsen J. V., Jones R. L. cGMP Is Required for Gibberellic Acid-Induced Gene Expression in Barley Aleurone. Plant Cell. 1996 Dec;8(12):2325–2333. doi: 10.1105/tpc.8.12.2325. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Poulsen C., Mai X. M., Borg S. A Lotus japonicus cDNA encoding an alpha subunit of a heterotrimeric G-protein. Plant Physiol. 1994 Aug;105(4):1453–1454. doi: 10.1104/pp.105.4.1453. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Romero L. C., Lam E. Guanine nucleotide binding protein involvement in early steps of phytochrome-regulated gene expression. Proc Natl Acad Sci U S A. 1993 Feb 15;90(4):1465–1469. doi: 10.1073/pnas.90.4.1465. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Rushton P. J., Macdonald H., Huttly A. K., Lazarus C. M., Hooley R. Members of a new family of DNA-binding proteins bind to a conserved cis-element in the promoters of alpha-Amy2 genes. Plant Mol Biol. 1995 Nov;29(4):691–702. doi: 10.1007/BF00041160. [DOI] [PubMed] [Google Scholar]
  30. Seo H. S., Kim H. Y., Jeong J. Y., Lee S. Y., Cho M. J., Bahk J. D. Molecular cloning and characterization of RGA1 encoding a G protein alpha subunit from rice (Oryza sativa L. IR-36). Plant Mol Biol. 1995 Mar;27(6):1119–1131. doi: 10.1007/BF00020885. [DOI] [PubMed] [Google Scholar]
  31. Suh B. C., Song S. K., Kim Y. K., Kim K. T. Induction of cytosolic Ca2+ elevation mediated by Mas-7 occurs through membrane pore formation. J Biol Chem. 1996 Dec 20;271(51):32753–32759. doi: 10.1074/jbc.271.51.32753. [DOI] [PubMed] [Google Scholar]
  32. Tucker E. B., Boss W. F. Mastoparan-Induced Intracellular Ca2+ Fluxes May Regulate Cell-to-Cell Communication in Plants. Plant Physiol. 1996 Jun;111(2):459–467. doi: 10.1104/pp.111.2.459. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Wang M., Sedee N. J., Heidekamp F., Snaar-Jagalska B. E. Detection of GTP-binding proteins in barley aleurone protoplasts. FEBS Lett. 1993 Aug 30;329(3):245–248. doi: 10.1016/0014-5793(93)80230-r. [DOI] [PubMed] [Google Scholar]
  34. Warpeha K. M., Hamm H. E., Rasenick M. M., Kaufman L. S. A blue-light-activated GTP-binding protein in the plasma membranes of etiolated peas. Proc Natl Acad Sci U S A. 1991 Oct 15;88(20):8925–8929. doi: 10.1073/pnas.88.20.8925. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Weiss C. A., Garnaat C. W., Mukai K., Hu Y., Ma H. Isolation of cDNAs encoding guanine nucleotide-binding protein beta-subunit homologues from maize (ZGB1) and Arabidopsis (AGB1). Proc Natl Acad Sci U S A. 1994 Sep 27;91(20):9554–9558. doi: 10.1073/pnas.91.20.9554. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Wu W. H., Assmann S. M. A membrane-delimited pathway of G-protein regulation of the guard-cell inward K+ channel. Proc Natl Acad Sci U S A. 1994 Jul 5;91(14):6310–6314. doi: 10.1073/pnas.91.14.6310. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Zwar J. A., Hooley R. Hormonal Regulation of alpha-Amylase Gene Transcription in Wild Oat (Avena fatua L.) Aleurone Protoplasts. Plant Physiol. 1986 Feb;80(2):459–463. doi: 10.1104/pp.80.2.459. [DOI] [PMC free article] [PubMed] [Google Scholar]

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