Overexpression of gene encoding tonoplast intrinsic aquaporin promotes urea transport in Arabidopsis

Sun Hee Kim, Kang Il Kim, Hyun Woo Ju, Hojoung Lee, Suk Whan Hong

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Complementation assay of the urea uptake-defective yeast mutants led to the identification of the Arabidopsis AtTIP4;1 gene encoding the aquaporin. However, its physiological functions still remain elusive. In the present study, histochemical and genetic analyses were performed to understand the physiological roles of AtTIP4;1 in urea uptake. The AtTIP4;1 product was detectible in the roots, but not in the leaves, the stem, and the flower. Its promoter allowed the expression of the β-glucuronidase reporter gene in the roots and the apical meristem in Arabidopsis. The AtTIP4;1 products were induced under nitrogen-deficient conditions. To investigate the role of the tonoplast intrinsic protein in urea transport and developments, Arabidopsis with the loss- and the gain-of-function mutations by T-DNA insertion in AtTIP4;1 and 35S promoter-mediated overexpression of AtTIP4;1 were identified, respectively. The transfer DNA insertion and the AtTIP4; 1-overexpressed plants showed normal growth and development under normal or abiotic stress growth conditions. The urea-uptake studies using 14C-labeled urea revealed higher accumulation of urea in the AtTIP4;1-overexpressed plants. These results provide evidence that overexpression of AtTIP4;1 leads to the increase in the urea-uptake rate in plants without detectable defects to the growth and development.

Original languageEnglish
Pages (from-to)102-110
Number of pages9
JournalJournal of Applied Biological Chemistry
Issue number3
Publication statusPublished - 2008 Jun 30


  • Aquaporins
  • T-DNA insertion mutant
  • Tonoplast intrinsic proteins (TIP)
  • Transgenic plants
  • Urea transport

ASJC Scopus subject areas

  • Bioengineering
  • Organic Chemistry


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