Comparative expression of β-glucuronidase with five different promoters in transgenic carrot (Daucus carota L.) root and leaf tissues

• Published in: Plant cell reports 2008-02, Vol.27 (2), p.279-287
• Main Authors: Wally, O, Jayaraj, J, Punja, Z. K
• Format: Article
• Language: English
• Subjects: Agrobacterium tumefaciens; Arabidopsis; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; carrots; Cauliflower mosaic virus; Cell Biology; Daucus; Daucus carota; Daucus carota - genetics; Daucus carota - growth & development; Daucus carota - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genetic engineering; Genetic technics; Genetic Transformation and Hybridization; Glucuronidase - genetics; Glucuronidase - metabolism; Life Sciences; Methods. Procedures. Technologies; Organ specific expression; Plant Biochemistry; Plant Leaves - genetics; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant Roots - genetics; Plant Roots - growth & development; Plant Roots - metabolism; Plant Sciences; Plants, Genetically Modified; Promoter; Promoter Regions, Genetic - genetics; Transgenic animals and transgenic plants; Transgenic plants; β-Glucuronidase
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-007-0461-1

Tissue-specific patterns and levels of protein expression were characterized in transgenic carrot plants transformed with the β-glucuronidase (GUS) gene driven by one of five promoters: Cauliflower mosaic virus 35S (35S) and double 35S (D35S), Arabidopsis ubiquitin (UBQ3), mannopine synthase (mas2) from Agrobacterium tumefaciens or the rooting loci promoter (rolD) from A. rhizogenes. Five independently transformed carrot lines of each promoter construct were assessed for GUS activity. In leaves, activity was highest in plants with the D35S, 35S and UBQ3 promoters, while staining was weak in plants with the mas2 promoter, and only slight visual staining was present in the leaf veins of plants containing rolD promoter . Strong staining was seen in the lateral roots, including root tips, hairs and the vascular tissues of plants expressing the 35S, D35S and UBQ3. Lateral roots of plants containing the rolD construct also showed staining in these tissues while the mas2 promoter exhibited heightened staining in the root tips. Relatively strong GUS staining was seen throughout the tap root with all the promoters tested.. When GUS expression was quantified, the UBQ3 promoter provided the highest activity in roots of mature plants, while plants with the D35S and 35S promoter constructs had higher activity in the leaves. Although plants containing the mas2 promoter had higher levels of activity compared to the rolD plants, these two promoters were significantly weaker than D35S, 35S and UBQ3. The potential for utilization of specific promoters to target expression of desired transgenes in carrot tissues is demonstrated.