Resveratrol is a stilbene phytoalexin well-known for its presence in grape, wine, and peanut. As a result of its antioxidant and chemopreventative properties, it has gained much attention as a functional food ingredient. A gas chromatography-mass spectrometry method for the detection of resveratrol, its 3-glucopyranoside piceid, and the cis isomers of both compounds has been developed and used to quantitate the levels of these compounds in the skin of commercially available tomato fruit (Lycopersicon esculentum Mill.). The resveratrol concentration remains relatively stable during fruit maturation, reaching a maximum concentration in the skin of 18.4 +/- 1.6 microg/g dry weight at 4 weeks postbreaker. No stilbenes were detected in the flesh of tomato fruit.

SummaryGenes encoding regulatory factors isolated from Arabidopsis , soybean and corn have been screened to identify those that modulate the expression of genes encoding for enzymes involved in the biosynthesis of morphinan alkaloids in opium poppy ( Papaver somniferum ) and benzophenanthridine alkaloids in California poppy ( Eschscholzia californica ). In opium poppy, the over-expression of selected regulatory factors increased the levels of PsCORtranscripts by 10-to more than 100-fold. These transcriptional activations translated into an enhancement of alkaloid production in opium poppy of up to at least 10-fold. In California poppy, the transactivation effect of regulatory factor WRKY1 resulted in an increase of up to 60-fold in the level of EcCYP80B1 [( S )-N -methylcoclaurine 3 ′ -hydroxylase] and EcBBE (berberine bridge enzyme) transcripts. As a result, the accumulations of selected alkaloid intermediates were enhanced up to 30-fold. The transactivation effects of other regulatory factors led to the accumulation of the same intermediates. These regulatory factors also led to the production of new alkaloids in California poppy callus culture.

Stable genetic transformation of barley is routinely carried out by co-cultivation of immature zygotic embryos with Agrobacterium tumefaciens carrying binary vectors (1, 2). The target gene and the selection marker are located between the left and right 25-bp direct repeats of the T-DNA borders either within a single or in two adjacent tandemly arranged cassettes (3). The transfer of the T-DNA is polar; an intact right border is required for the transfer, whereas mutations in the left border have little effect on transfer efficiency (4). A single-stranded copy of the lower T-DNA strand is generated from endonucleolytic cleavage sites between the third and fourth bases of the border repeats. The strand is covered with the single-stranded DNA binding protein VirE2, covalently bound to the VirD2 protein at the 5Ј end and exported from the bacterium (4, 5). The VirE1 protein assists in secretion of virE2, which appears to form a voltage gated channel through the plasma membrane of the plant cell (6). The DNA is transported through the channel and guided by several proteins into the cell nucleus. The single-strand T-DNA then probably invades the DNA of the plant chromosome and is integrated by illegitimate recombination followed by secondstrand synthesis. Alternatively a double-stranded form might be generated first and then integrated into the chromosome (5).Details of integration have been primarily investigated in tobacco and Arabidopsis (7-10). Small deletions, base substitutions, duplicated border, and genomic sequences are found around the T-DNA͞plant DNA junctions. Co-integration into a chromosome locus after extrachromosomal second strand synthesis and ligation of the different T-DNA molecules, followed by docking and insertion via double-stranded breaks and repair synthesis is supported by analysis of co-integration of two or more T-DNAs in the same locus (11). All ten possible combinations-i.e., inverted as well as tandem arrangementsoccurred with regard to the left and right borders. The junction regions of direct repeats of T-DNA were investigated by selecting these with a vector containing a promoterless kanamycin phosphotransferase gene near the right border and a 35S CaMV promoter near the left border (12). Transformants from two T-DNA strands linking the promoter with the gene were selected on media containing kanamycin and revealed integrated T-DNA strands with a precise junction as well as integrations with 8 to 293 bp of filler DNA. Binary vectors carrying a neomycin phosphotransferase gene driven by a nopalinsynthase promoter within the T-DNA and a ␤-glucuronidase (gus) reporter gene under the control of a mannopine synthase promoter outside the left or right border resulted in 75% of transgenic tobacco plants containing the uidA (gus) gene unlinked or linked to the left or right border of the integrated T-DNA (13). Such incorporation of vector backbone sequences can be avoided by cotransformation of the target gene with the virD1, virD2, and virE2 virulence genes within the left and right border ...