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.

Novel and Mechanical Stress-Responsive MicroRNAs in Populus trichocarpa That Are Absent from Arabidopsis

Shanfa Lu, Ying-Hsuan Sun, Rui Shi, Catherine Clark, Laigeng Li and Vincent L. Chiang
The Plant Cell
Vol. 17, No. 8 (Aug., 2005), pp. 2186-2203
Stable URL: http://www.jstor.org/stable/4130948
Page Count: 18
  • 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.
Novel and Mechanical Stress-Responsive MicroRNAs in Populus trichocarpa That Are Absent from Arabidopsis
Preview not available

Abstract

MicroRNAs (miRNAs) are small, noncoding RNAs that can play crucial regulatory roles in eukaryotes by targeting mRNAs for silencing. To test whether miRNAs play roles in the regulation of wood development in tree species, we isolated small RNAs from the developing xylem of Populus trichocarpa stems and cloned 22 miRNAs. They are the founding members of 21 miRNA gene families for 48 miRNA sequences, represented by 98 loci in the Populus genome. A majority of these miRNAs were predicted to target developmental- and stress/defense-related genes and possible functions associated with the biosynthesis of cell wall metabolites. Of the 21 P. trichocarpa miRNA families, 11 have sequence conservation in Arabidopsis thaliana but exhibited species-specific developmental expression patterns, suggesting that even conserved miRNAs may have different regulatory roles in different species. Most unexpectedly, the remaining 10 miRNAs, for which 17 predicted targets were experimentally validated in vivo, are absent from the Arabidopsis genome, suggesting possible roles in tree-specific processes. In fact, the expression of a majority of the cloned miRNAs was upregulated or downregulated in woody stems in a manner consistent with tree-specific corrective growth against tension and compression stresses, two constant mechanical loads in trees. Our results show that plant miRNAs can be induced by mechanical stress and may function in one of the most critical defense systems for structural and mechanical fitness.

Page Thumbnails

  • Thumbnail: Page 
[2186]
    [2186]
  • Thumbnail: Page 
2187
    2187
  • Thumbnail: Page 
2188
    2188
  • Thumbnail: Page 
2189
    2189
  • Thumbnail: Page 
2190
    2190
  • Thumbnail: Page 
2191
    2191
  • Thumbnail: Page 
2192
    2192
  • Thumbnail: Page 
2193
    2193
  • Thumbnail: Page 
2194
    2194
  • Thumbnail: Page 
2195
    2195
  • Thumbnail: Page 
2196
    2196
  • Thumbnail: Page 
2197
    2197
  • Thumbnail: Page 
2198
    2198
  • Thumbnail: Page 
2199
    2199
  • Thumbnail: Page 
2200
    2200
  • Thumbnail: Page 
2201
    2201
  • Thumbnail: Page 
2202
    2202
  • Thumbnail: Page 
2203
    2203