Journal Article

Modulation of eIF5A1 expression alters xylem abundance in <i>Arabidopsis thaliana</i>

Zhongda Liu, Jeremy Duguay, Fengshan Ma, Tzann-Wei Wang, Ruth Tshin, Marianne T. Hopkins, Linda McNamara and John E. Thompson

in Journal of Experimental Botany

Published on behalf of Society for Experimental Biology

Volume 59, issue 4, pages 939-950
Published in print March 2008 | ISSN: 0022-0957
Published online February 2008 | e-ISSN: 1460-2431 | DOI: http://dx.doi.org/10.1093/jxb/ern017

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Eukaryotic translation initiation factor 5A (eIF5A) is thought to facilitate protein synthesis by participating in the nuclear export of specific mRNAs. In Arabidopsis, there are three isoforms of eIF5A. One of them, AteIF5A1, has been shown to be expressed in vascular tissue, specifically developing vessel members, using GUS as a reporter. In order to determine whether AteIF5A1 plays a role in xylem formation, its full-length cDNA was constitutively over-expressed in transgenic Arabidopsis plants. Microscopic analysis revealed that the cross-sectional area of the xylem in the main inflorescence stems of transgenic plants was 1.9-fold higher than those of corresponding inflorescence stems of wild-type plants. In wild-type stems, the primary xylem typically comprised six cell layers and was ∼105 μm thick, but increased to 9–11 cell layers, 140–155 μm thick, in transgenic stems. Similarly, the secondary xylem increased from six cell layers, ∼70 μm thick, in control stems to ∼9 cell layers, 95–105 μm thick, in transgenic stems. Moreover, constitutive down-regulation of AteIF5A1 using antisense technology resulted in the major suppression of xylem formation compared with control plants, and the antisense transgenic plants were also stunted. These data collectively indicate that eIF5A1 plays a role in xylogenesis.

Keywords: Arabidopsis thaliana; eukaryotic translation initiation factor 5A; inflorescence stem; xylem

Journal Article.  6273 words.  Illustrated.

Subjects: Plant Sciences and Forestry

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