Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Action of Inhibitors of RNA and Protein Synthesis on Cell Enlargement

Larry D. Noodén and Kenneth V. Thimann
Plant Physiology
Vol. 41, No. 1 (Jan., 1966), pp. 157-164
Stable URL: http://www.jstor.org/stable/4260621
Page Count: 8
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Action of Inhibitors of RNA and Protein Synthesis on Cell Enlargement
Preview not available

Abstract

Further studies with inhibitors of protein synthesis are presented to support the conclusion, drawn from work with chloramphenicol, that protein synthesis is a critical limiting factor in auxin-induced cell expansion. The indoleacetic acid-induced elongation of oat coleoptile sections was strongly inhibited by DL-p-fluorophenylalanine, and the inhibition is antagonized by phenylalanine. Puromycin at 10-4 M very strongly inhibited the indoleacetic acid-induced growth of oat coleoptile and artichoke tuber sections and exerted a less powerful effect on pea stem sections. As found earlier with chloramphenicol, concentrations of puromycin effective in inhibiting the growth of coleoptile sections had quantitatively similar effects on protein synthesis, as measured by the incorporation of C14-leucine into protein of the coleoptile tissue. Several analogues of RNA bases were also tested, but while 8-azaguanine very strongly inhibited growth of artichoke tuber disks, 6-azauracil was the only one of this group clearly inhibitory to growth in coleoptile or pea stem sections. Actinomycin D actively inhibited both elongation and the incorporation of C14-leucine into protein in oat coleoptile sections. Inhibition of the 2 processes went closely parallel. Actinomycin D also powerfully inhibited growth of artichoke tuber disks. All the compounds effective in inhibiting growth generally inhibited the uptake of leucine as well. The possibility that auxin causes cell enlargement in plants by inducing the synthesis of a messenger RNA and of one or more new but unstable enzymes, is discussed. Possible but less favored alternative explanations are: A) that auxin induces synthesis of a wall protein, or B) that the continued synthesis of some other unstable protein (by a process independent of auxin) may be a prerequisite for cell enlargement.

Page Thumbnails

  • Thumbnail: Page 
157
    157
  • Thumbnail: Page 
158
    158
  • Thumbnail: Page 
159
    159
  • Thumbnail: Page 
160
    160
  • Thumbnail: Page 
161
    161
  • Thumbnail: Page 
162
    162
  • Thumbnail: Page 
163
    163
  • Thumbnail: Page 
164
    164