Promoter activity associated with the intergenic regions of banana bunchy top virus DNA-1 to -6 in transgenic tobacco and banana cells.

Abstract

Promoter regions associated with each of the six ssDNA components of banana bunchy top virus (BBTV) have been characterized. DNA segments incorporating the intergenic regions of BBTV DNA-1 to -6 were isolated and fused to the uidA (β-glucuronidase) reporter gene to assess promoter activity. In tobacco cell suspensions, the BBTV DNA-2 and -6 promoters generated levels of GUS expression 2-fold greater and similar to the 800 bp CaMV 35S promoter, respectively. Deletion analysis of the BBTV DNA-6 promoter suggested all the necessary promoter elements required for strong expression were located within 239 nucleotides upstream of the translational start codon. In transgenic tobacco plants, the BBTV-derived promoters generally provided a weak, tissue-specific GUS

Banana bunchy top disease (BBTD) symptom expression in banana and strategies for transgenic resistance: A review

“…The CR-M comprises three relatively conserved domains (domain I, II and III) and short primer sequences that map to this region (5' of CR-M, domains I and II) have been isolated from BBTV virions (Hafner et al, 1997a), indicating its role in second strand synthesis of circular ssDNA genomic components. The promoter and terminator regions that drive the expression of encoded ORFs are located within the IR and have been shown to be active in both monocot and dicot embryogenic cells with significant activity in vascular-associated tissue (Dugdale et al, 1998;.…”

Advances in Small Isometric Multicomponent ssDNA Viruses Infecting Plants

“…Genomics of these viruses opened up new area of studies that they are the source of promoters [19,83,88] for gene expression in plant and vectors that provide efficient expression system for studying in planta protein-protein interactions [5].…”

“…The DNA components of BBTV have potential source of promoters. Assessment of DNA components 1-6 showed that the promoters are functional in both monocot and dicot plants [19]. Promoter from DNA component-2 showed greater efficacy compared to 35S promoter from Cauliflower mosaic virus.…”

A promoter derived from taro bacilliform badnavirus drives strong expression in transgenic banana and tobacco plants

“…3 Schematic representation of plasmids used for either comparison of commonly used promoters with TaBV-derived promoters and/or as selectable markers. Ubi-1; Promoter region from maize polyubiquitin-1 gene, Ubi-1 intron; first exon and intron from maize polyubiquitin-1 gene, GFP; gene coding for green fluorescent protein, nos 3 0 3 0 ; untranslated region from gene coding for Agrobacterium tumefaciens nopaline synthase, CaMV 35S; promoter region from gene coding for cauliflower mosaic virus (CaMV) 35S RNA, uidA; gene coding for b-glucuronidase (GUS), RbcS 3 0 3 0 ; untranslated region from gene coding for Nicotiana tabacum rubisco, BT6.3; promoter region from DNA-6 from banana bunchy top virus (Dugdale et al 1998), nptII; gene coding for neomycin phosphotransferase II, 35S 3 0 3 0 ; untranslated region from gene coding for CaMV virus 35S RNA, D35S; double CaMV 35S promoter, RB; right border of binary vector T-DNA region, LB; left border of binary vector T-DNA region in a single directional cloning step into PstI/NcoI-digested vectors, pGEM-BS2P-GFP-NOS and pBaI-S-GUS-RbcS, respectively, creating pT1200-GFP and pT1200-GUS.…”

“…For biolistic transformation, plasmids p35S-GFP and pUbi-GFP were used as positive controls for comparisons of GFP expression directed by different promoters. The plasmid p35S-GFP/BT6.3-NPT was used as a CaMV 35S-GFP control in banana plants stably transformed using particle bombardment while pBT6.3-Ubi-NPT was used for co-transformation with other test and control plasmids that did not contain a selectable marker (Becker et al 2000;Dugdale et al 1998). Plasmids used for comparisons of GUS expression directed by different promoters were pGUS2 and pUGR73 (Christensen and Quail 1996), which were kindly provided by Linda Tabe and David McElroy (Division of Plant Industry, CSIRO, Canberra).…”