Skip to main content
NCBI home page
Plant Physiology logoLink to Plant Physiology
. 1997 Jul;114(3):1095–1101. doi: 10.1104/pp.114.3.1095

Regulation of acyltransferase activity in immature maize embryos by abscisic acid and the osmotic environment.

F Pacheco-Moisés 1, L Valencia-Turcotte 1, M Altuzar-Martínez 1, R Rodríguez-Sotres 1
PMCID: PMC158399  PMID: 9232885

Abstract

Maize (Zes mays L.) embryos, isolated from the developing seed and incubated in dilute buffer, show reduced triacylglycerol (TAG) synthesis, and accumulation stops after 24 h. Synthesis and accumulation can be maintained at high levels if the incubation medium contains abscisic acid (ABA) and/or a high osmotic concentration. Radiolabeled free fatty acids accumulate at higher levels in embryos that contain less TAG, and acetyl coenzyme A carboxylase activity remains essentially unchanged under all of the conditions tested. In contrast, the activities of the acyltransferases required for TAG synthesis remain high only in embryos incubated with ABA and/or a high osmotic concentration. Dose-response curves showed that 4 microM of ABA or mannitol at -1.0 MPa elicits a full response; both values are within the range considered to be physiological. The TAG synthesis capacity and discylglycerol acyltransferase activity lost by pretreatment of the embryos can be restored by re-exposure to ABA or high osmoticum. Germination is not involved because isolated scutellum halves showed the same changes in enzyme activity found in the whole embryo but did not germinate. Our results provide direct evidence for the regulation of TAG-synthesizing activities in maize embryos by ABA and the osmotic potential of the environment.

Full Text

The Full Text of this article is available as a PDF (830.2 KB).

Selected References

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

  1. Balsevich J. J., Cutler A. J., Lamb N., Friesen L. J., Kurz E. U., Perras M. R., Abrams S. R. Response of Cultured Maize Cells to (+)-Abscisic Acid, (-)-Abscisic Acid, and Their Metabolites. Plant Physiol. 1994 Sep;106(1):135–142. doi: 10.1104/pp.106.1.135. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bertrams M., Heinz E. Positional Specificity and Fatty Acid Selectivity of Purified sn-Glycerol 3-Phosphate Acyltransferases from Chloroplasts. Plant Physiol. 1981 Sep;68(3):653–657. doi: 10.1104/pp.68.3.653. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Egli M. A., Gengenbach B. G., Gronwald J. W., Somers D. A., Wyse D. L. Characterization of Maize Acetyl-Coenzyme A Carboxylase. Plant Physiol. 1993 Feb;101(2):499–506. doi: 10.1104/pp.101.2.499. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Ichihara K., Takahashi T., Fujii S. Diacylglycerol acyltransferase in maturing safflower seeds: its influences on the fatty acid composition of triacylglycerol and on the rate of triacylglycerol synthesis. Biochim Biophys Acta. 1988 Jan 19;958(1):125–129. doi: 10.1016/0005-2760(88)90253-6. [DOI] [PubMed] [Google Scholar]
  5. Katavic V., Reed D. W., Taylor D. C., Giblin E. M., Barton D. L., Zou J., Mackenzie S. L., Covello P. S., Kunst L. Alteration of seed fatty acid composition by an ethyl methanesulfonate-induced mutation in Arabidopsis thaliana affecting diacylglycerol acyltransferase activity. Plant Physiol. 1995 May;108(1):399–409. doi: 10.1104/pp.108.1.399. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  7. Oo K. C., Huang A. H. Lysophosphatidate acyltransferase activities in the microsomes from palm endosperm, maize scutellum, and rapeseed cotyledon of maturing seeds. Plant Physiol. 1989 Dec;91(4):1288–1295. doi: 10.1104/pp.91.4.1288. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Post-Beittenmiller D., Roughan G., Ohlrogge J. B. Regulation of plant Fatty Acid biosynthesis : analysis of acyl-coenzyme a and acyl-acyl carrier protein substrate pools in spinach and pea chloroplasts. Plant Physiol. 1992 Oct;100(2):923–930. doi: 10.1104/pp.100.2.923. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Skriver K., Mundy J. Gene expression in response to abscisic acid and osmotic stress. Plant Cell. 1990 Jun;2(6):503–512. doi: 10.1105/tpc.2.6.503. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Smith P. K., Krohn R. I., Hermanson G. T., Mallia A. K., Gartner F. H., Provenzano M. D., Fujimoto E. K., Goeke N. M., Olson B. J., Klenk D. C. Measurement of protein using bicinchoninic acid. Anal Biochem. 1985 Oct;150(1):76–85. doi: 10.1016/0003-2697(85)90442-7. [DOI] [PubMed] [Google Scholar]
  11. Somers D. A., Keith R. A., Egli M. A., Marshall L. C., Gengenbach B. G., Gronwald J. W., Wyse D. L. Expression of the Acc1 Gene-Encoded Acetyl-Coenzyme A Carboxylase in Developing Maize (Zea mays L.) Kernels. Plant Physiol. 1993 Mar;101(3):1097–1101. doi: 10.1104/pp.101.3.1097. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Ting J. T., Lee K., Ratnayake C., Platt K. A., Balsamo R. A., Huang A. H. Oleosin genes in maize kernels having diverse oil contents are constitutively expressed independent of oil contents. Size and shape of intracellular oil bodies are determined by the oleosins/oils ratio. Planta. 1996;199(1):158–165. doi: 10.1007/BF00196892. [DOI] [PubMed] [Google Scholar]
  13. Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES