Nucleotide homologies between the glycosylated seed storage proteins ofGlycine max andPhaseolus vulgaris

We have compared the partial nucleotide and derived amino acid sequences of a phaseolin seed storage protein gene ofPhaseolus vulgaris (1) and a conglycinin storage protein gene ofGlycine max (2). Although these proteins are not antigenically related to one another, the architecture of the genes is similar throughout the sequences compared here. Intervening sequences interrupt the same amino acid positions in both genes. Within the 28% of theG. max gene and the 38% of theP. vulgaris gene represented in this comparison, 73% of the nucleotides in the coding and intervening sequences are identical, excluding the insertions and deletions. The nucleotide mismatches found in the coding sequences are distributed throughout the three codon positions with little bias towards the third codon position. In addition to the single nucleotide differences, six insertions or deletions, ranging from three to twenty-seven nucleotides in length, occur in this portion of the coding region and these are partially responsible for the molecular weight differences of the conglycinin α′-subunit and the phaseolin subunit.     

Regeneration of fertile transgenic indica (group 1) rice plants following microprojectile transformation of embryogenic suspension culture cells

Regenerable embryogenic suspensions of elite Indica (group 1) rice varieties IR24, IR64, IR72 and an advanced Indica rice breeding line IR57311-95-2-3 were established within 6–8 weeks from 3–4 week old calli derived from mature seeds. Transgenic rice plants were obtained by introducing a plasmid carrying genes encoding hygromycin phosphotransferase (hph, conferring resistance to hygromycin B) and ß-glucuronidase (uidA), both driven by the CaMV 35S promoter, via particle bombardment of embryogenic suspensions. The effect of osmotic conditioning on transformation was evaluated. Regenerated plants were resistant to hygromycin B and expressed the uidA (GUS) gene. The growth of mother plants (R₀) was normal and seeds were produced. Southern blot analysis of R₀ and R₁ plants showed that hygromycin resistant plants contained intact hph genes that were inherited in a Mendelian fashion. A protocol for a simple, efficient, repeatable, genotype- and environment-independent Indica rice transformation system is described.Abbreviations 2,4-D 2,4-dichlorophenoxy acetic acid - NAA -naphthalene acetic acid - kb kilobase - GUS ß-glucuronidase - hph hygromycin B phosphotransferase     

Inactivation of the nopaline synthase gene by double transformation: reactivation by segregation of the induced DNA

Tobacco plants were transformed with derivatives of a binary vector pMON505 and two kanamycin resistant lines that were nopaline positive were selected for second transformation. The plasmids used for the second transformation were derivatives of pMON850 which carries the nopaline synthase gene in addition to a gene for gentamicin resistance. Insertion of each transgene was confirmed by Southern hybridization. Surprisingly, we found that more than 50% of the doubly transformed tobacco plants were nopaline negative. Tobacco plants that were transformed only by the second vector exhibited nopaline accumulation. DNA methylation patterns at the HpaII site in the promoter region of the nopaline synthase gene did not correlate with the nopaline phenotype. In some plant lines, seedlings of the R1 generation which segregated out the second T-DNA insertion recovered the nop⁺ phenotype. These results indicate that nopaline accumulation was inhibited by the presence of the second T-DNA.Abbreviations T-DNA transferred DNA - NPTII neomycin phosphotransferase II - uidA -glucuronidase - Km kanamycin - Gm gentamicin - nop⁺ nopaline positive - nop^– nopaline negative - MS medium, Murashige-Skoog medium     

Expression of the tobacco mosaic virus movement protein alters starch accumulation inNicotiana benthamiana

Nicotiana benthamiana plants were transformed with the movement protein (MP) gene of tobacco mosaic virus (TMV), usingAgrobacterium-mediated transformation. Plants regenerated from the transformed cells accumulated 30-kDa MP and complemented the activity of TMV MP when infected with chimeric TMVs containing defective MR These transgenic plants displayed stunting, pale-green leaves, and starch accumulations, indicating that TMV MP altered the carbon partitioning for leaves involved in TMV cell-to-cell movement.