Tissue-Preferential Expression of a Rice α-Tubulin Gene, OsTubA1, Mediated by the First Intron

• Published in: Plant physiology (Bethesda) 2000-07, Vol.123 (3), p.1005-1014
• Main Authors: Jeon, Jong-Seong, Lee, Sichul, Jung, Ki-Hong, Sung-Hoon Jun, Kim, Chanhong, An, Gynheung
• Format: Article
• Language: English
• Subjects: Blotting, Northern; Corn; Exons; Gene expression; Gene Expression Regulation, Plant; Genes; Genes, Reporter; Genetics, Genomics, and Molecular Evolution; Glucuronidase - genetics; Glucuronidase - metabolism; Introns; Leaves; Oryza - genetics; Oryza - metabolism; Oryza sativa; OsTubA1 gene; Plants; Plants, Genetically Modified; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Rice; RNA; RNA, Messenger - analysis; Transgenic plants; Tubulin - genetics; Tubulin - metabolism
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.123.3.1005

The genomic clone encoding an α-tubulin, OsTubA1, has been isolated from rice (Oryza sativa L.). The gene consists of four exons and three introns. RNA-blot analysis showed that the gene is strongly expressed in actively dividing tissues, including root tips, young leaves, and young flowers. Analysis of chimeric fusions between OsTubA1 and β-glucuronidase (GUS) revealed that the intron 1 was required for high-level GUS expression in actively dividing tissues, corresponding with normal expression pattern of OsTubA1. Fusion constructs lacking the intron 1 showed more GUS staining in mature tissues rather than young tissues. When the intron 1 was placed at the distal region from 5′-upstream region or at the 3′-untranslated region, no enhancement of GUS expression was observed. Sequential deletions of the OsTubA1 intron 1 brought about a gradual reduction of GUS activity in calli. These results suggest that tissue-preferential expression of the OsTubA1 gene is mediated by the intron 1 and that it may be involved in a mechanism for an efficient RNA splicing that is position dependent.