Identification of differentially expressed genes associated with 5-methyltryptophan resistance in rice mutants

D. S. Kim, C. S. Jang, J. B. Kim, G. J. Lee, S. Y. Kang, W. Kim, Y. W. Seo

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2 Citations (Scopus)


5-Methyltryptophan (5MT), a tryptophan analog, resistant M4 rice mutants with high free amino acid contents were obtained through in vitro mutagenesis. To evaluate the 5MT resistance mechanism, a cDNA library was constructed by using the leaves and roots of the 5MT resistant mutant plants. Expressed sequenced tags (ESTs) of 1 019 randomly selected clones were analyzed and then assembled 588 unigens. A total of 389 unigenes had significant homologies with known protein sequences at the NCBI database and the remaining 199 unigenes were designated unidentified genes. These unigens were grouped into 13 categories according to their putative functions. Of the 233 randomly selected clones, 25 were identified as differentially expressed genes between 5MT resistant and 5MT sensitive wild type plants. For further study of the differential expression of the genes, expression patterns of 12 genes related to various biological functions were evaluated in response to 5MT treatment in both the resistant plants and sensitive plants. All of the tested 12 genes exhibited higher expression levels in mutant plants than wild type plants under the 5MT inhibition. These expression patterns of the 12 genes suggested that the genes related to 5MT resistance in the rice mutants have a variety of functions, and yield remarkably diverse expression patterns upon 5MT treatment. Many genes that were identified tend to be related to defense and stress responses, suggesting "cross-talking" between biotic/abiotic stresses including the 5MT treatment. Therefore, 5MT resistant mutants might be of value for identifying genes related to plant defenses and stresses.

Original languageEnglish
Pages (from-to)444-450
Number of pages7
JournalBiologia Plantarum
Issue number3
Publication statusPublished - 2009

Bibliographical note

Funding Information:
Received 30 July 2007, accepted 10 May 2008. Abbreviations: ESTs - expressed sequence tags; ROS - reactive oxygen species; 5MT - 5-methyltryptophan. Acknowledgements: This work was supported by a grant (Code 20070501034005) from BioGreen 21 Program, RDA (Rural Development Administration), and a grant (code 308020051SB040) from Agricultural R&D Promotion Center, Korea Rural Economic Institute, Republic of Korea. Equally contributed corresponding authors;1fax: (+82) 63 570 3319, e-mail:; 2fax: (+82) 2 3290 3005; e-mail:


  • Abiotic stress
  • Expressed sequence tags
  • Northern blot
  • Oryza sativa

ASJC Scopus subject areas

  • Plant Science
  • Horticulture


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