Skip to main content
NCBI home page
Plant Physiology logoLink to Plant Physiology
. 1968 Feb;43(2):140–150. doi: 10.1104/pp.43.2.140

Studies on the Role of RNA Synthesis in Auxin Induction of Cell Enlargement 1

Larry D Nooden 1,2
PMCID: PMC1086813  PMID: 16656747

Abstract

Selective inhibitors were used to study the connection between nucleic acid synthesis and indoleacetic acid (IAA) induction of cell enlargement. Actinomycin D (act D) and azaguanine (azaG) almost completely inhibit IAA-induced growth in aged artichoke tuber disks when they are added simultaneously with IAA. In contrast, when they are added 24 hours after the hormone, these inhibitors have little or no effect on the induced growth which continues for 48 hours or more with little or no inhibition. Inhibitors of protein synthesis still stop growth when applied 24 hours after the IAA, thus protein synthesis and presumably supporting metabolism are still essential.

In corn coleoptile sections auxin-induced growth did not show any pronounced tendency to become less sensitive to act D as the IAA treatment progressed. Act D did not completely inhibit the response to IAA unless the sections were pretreated with act D for 6 hours. In contrast to act D, cordycepin produced almost complete inhibition of IAA-induced growth when added with the IAA.

Although IAA has a very large and very rapid stimulatory effect (within 10 min) on incorporation of 32P-orthophosphate into RNA in disks, it did not cause a detectable change in the base composition of the RNA synthesized. Furthermore, the promotive effect could be accounted for through increased uptake of the 32P. That much of the RNA synthesis in these tissues is not necessary for auxin action is indicated by the results with fluorouracil (FU). FU strongly inhibits RNA synthesis, probably acting preferentially on ribosomal RNA synthesis, without inhibiting auxin-induced growth in the disks or coleoptile sections. FU also strongly inhibited respiration in auxin-treated disks indicating that the large promotion of respiration by auxin likewise may not be entirely necessary for growth.

At least in the artichoke disks, RNA synthesis is required for auxin induction of cell enlargement and not for cell enlargement itself.

The possible relationships of auxin induction of cell enlargement and RNA synthesis are discussed.

Full text

PDF
140

Selected References

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

  1. Armstrong D. J. Hypothesis concerning the mechanism of auxin action. Proc Natl Acad Sci U S A. 1966 Jul;56(1):64–66. doi: 10.1073/pnas.56.1.64. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. BANCROFT J. B., KEY J. L. EFFECT OF ACTINOMYCIN D AND ETHYLENEDIAMINE TETRAACETIC ACID ON THE MULTIPLICATION OF A PLANT VIRUS IN ETIOLATED SOYBEAN HYPOCOTYLS. Nature. 1964 May 16;202:729–730. doi: 10.1038/202729a0. [DOI] [PubMed] [Google Scholar]
  3. CLICK R. E., HACKETT D. P. THE ROLE OF PROTEIN AND NUCLEIC ACID SYNTHESIS IN THE DEVELOPMENT OF RESPIRATION IN POTATO TUBER SLICES. Proc Natl Acad Sci U S A. 1963 Aug;50:243–250. doi: 10.1073/pnas.50.2.243. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Carpenter W. J., Cherry J. H. Effects of protein inhibitors and auxin on nucleic Acid metabolism in peanut cotyledons. Plant Physiol. 1966 Jun;41(6):919–922. doi: 10.1104/pp.41.6.919. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Grünberger D., O'Neal C., Nirenberg M. Stimulation of amino acid incorporation into protein by polyuridylic-8-azaguanylic acid. Biochim Biophys Acta. 1966 Jun 22;119(3):581–585. doi: 10.1016/0005-2787(66)90134-1. [DOI] [PubMed] [Google Scholar]
  6. Hamilton T. H., Moore R. J., Rumsey A. F., Means A. R., Schrank A. R. Stimulation of synthesis of ribonucleic acid in sub-apical sections of Avena coleoptile by indolyl-3-acetic acid. Nature. 1965 Dec 18;208(5016):1180–1183. doi: 10.1038/2081180a0. [DOI] [PubMed] [Google Scholar]
  7. Honig G. R., Rabinovitz M. Inhibition by actinomycin D of oxidation-dependent biosynthesis in Sarcoma 37 ascites cells. J Biol Chem. 1966 Apr 25;241(8):1681–1687. [PubMed] [Google Scholar]
  8. KITAZUME Y., YCAS M. THE CALCULATED COMPOSITION OF NEWLY SYNTHESIZED YEAST RIBONUCLEIC ACID. Biochim Biophys Acta. 1963 Nov 22;76:391–400. [PubMed] [Google Scholar]
  9. Kefford N. P. Auxin-Gibberellin Interaction in Rice Coleoptile Elongation. Plant Physiol. 1962 May;37(3):380–386. doi: 10.1104/pp.37.3.380. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Key J. L. Effect of purine and pyrimidine analogues on growth and RNA metabolism in the soybean hypocotyl-the selective action of 5-fluorouracil. Plant Physiol. 1966 Oct;41(8):1257–1264. doi: 10.1104/pp.41.8.1257. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Key J. L. Ribonucleic Acid and Protein Synthesis as Essential Processes for Cell Elongation. Plant Physiol. 1964 May;39(3):365–370. doi: 10.1104/pp.39.3.365. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. LOENING U. E. THE SYNTHESIS OF MESSENGER AND RIBOSOMAL RNA IN PEA SEEDLINGS AS DETECTED BY ELECTROPHORESIS. Proc R Soc Lond B Biol Sci. 1965 Mar 16;162:121–136. doi: 10.1098/rspb.1965.0028. [DOI] [PubMed] [Google Scholar]
  13. Nitsan J., Lang A. DNA synthesis in the elongating nondividing cells of the lentil epicotyl and its promotion by gibberellin. Plant Physiol. 1966 Jun;41(6):965–970. doi: 10.1104/pp.41.6.965. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Noodén L. D., Thimann K. V. EVIDENCE FOR A REQUIREMENT FOR PROTEIN SYNTHESIS FOR AUXIN-INDUCED CELL ENLARGEMENT. Proc Natl Acad Sci U S A. 1963 Aug;50(2):194–200. doi: 10.1073/pnas.50.2.194. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Noodén L. D., Thimann K. V. Inhibition of protein synthesis and of auxin-induced growth by chloramphenicol. Plant Physiol. 1965 Jan;40(1):193–201. doi: 10.1104/pp.40.1.193. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Parisi B., Ciferri O. Protein synthesis by cell-free extracts from castor bean seedlings. I. Preparation and characteristics of the amino acid incorporating system. Biochemistry. 1966 May;5(5):1638–1645. doi: 10.1021/bi00869a027. [DOI] [PubMed] [Google Scholar]
  17. Schweet R., Heintz R. Protein synthesis. Annu Rev Biochem. 1966;35:723–758. doi: 10.1146/annurev.bi.35.070166.003451. [DOI] [PubMed] [Google Scholar]
  18. Setterfield G. Growth regulation in excised slices of Jerusalem artichoke tuber tissue. Symp Soc Exp Biol. 1963;17:98–126. [PubMed] [Google Scholar]
  19. Shigeura H. T., Boxer G. E., Meloni M. L., Sampson S. D. Structure--activity relationship of some purine 3'-deoxyribonucleosides. Biochemistry. 1966 Mar;5(3):994–1004. doi: 10.1021/bi00867a027. [DOI] [PubMed] [Google Scholar]
  20. Sperling E., Laties G. G. The Dependence of Auxin-induced Growth on Auxin-independent Metabolic Changes in Slices of Storage Tissue. Plant Physiol. 1963 Sep;38(5):546–550. doi: 10.1104/pp.38.5.546. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Studzinski G. P., Baserga R. Instability of puromycin. Nature. 1966 Oct 8;212(5058):196–197. doi: 10.1038/212196a0. [DOI] [PubMed] [Google Scholar]
  22. de Kloet S. R., Strijkert P. J. Selective inhibition of ribosomal RNA synthesis in Saccharomyces carlsbergensis by 5-fluorouracil. Biochem Biophys Res Commun. 1966 Apr 6;23(1):49–55. doi: 10.1016/0006-291x(66)90267-1. [DOI] [PubMed] [Google Scholar]

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

RESOURCES