Organophosphorus hydrolase (OPH) was displayed and anchored onto the surface of Escherichia coli using an Lpp-OmpA fusion system. Production of the fusion proteins in membrane fractions was verified by immunoblotting with OmpA antisera. Inclusion of the organophosphorus hydrolase signal sequence was necessary for achieving enzymatic activity on the surface. More than 80% of the OPH activity was located on the cell surface as determined by protease accessibility experiments. Whole cells expressing OPH on the cell surface degraded parathion and paraoxon very effectively without any diffusional limitation, resulting in sevenfold higher rates of parathion degradation compared with whole cells with similar levels of intracellular OPH. Immobilization of these live biocatalysts onto solid supports could provide an attractive means for pesticide detoxification in place of immobilized enzymes, affording a reduced diffusional barrier.

The nucleotide sequence of an infectious clone of figwort mosaic virus (FMV) was determined using the dideoxynucleotide chain termination method. The double-stranded DNA genome (7743 base pairs) contained eight open reading frames (ORFs), seven of which corresponded approximately in size and location to the ORFs found in the genome of cauliflower mosaic virus (CaMV) and carnation etched ring virus (CERV). ORFs I and V of FMV demonstrated the highest degrees of nucleotide and amino acid sequence homology with the equivalent coding regions of CaMV and CERV. Regions II, III and IV showed somewhat less homology with the analogous regions of CaMV and CERV, and ORF VI showed homology with the corresponding gene of CaMV and CERV in only a short segment near the middle of the putative gene product. A 16 nucleotide sequence, complementary to the 3' terminus of methionine initiator tRNA (tRNAimet) and presumed to be the primer binding site for initiation of reverse transcription to produce minus strand DNA, was found in the FMV genome near the discontinuity in the minus strand. Sequences near the three interruptions in the plus strand of FMV DNA bear strong resemblance to similarly located sequences of 3 other caulimoviruses and are inferred to be initiation sites for second strand DNA synthesis. Additional conserved sequences in the small and large intergenic regions are pointed out including a highly conserved 35 bp sequence that occurs in the latter region.

The pericarp of Capsicum fruit is a rich dietary source of carotenoids. Accumulation of these compounds may be controlled, in part, by gene transcription of biosynthetic enzymes. The carotenoid composition in a number of orange-coloured C. annuum cultivars was determined using HPLC and compared with transcript abundances for four carotenogenic enzymes, Psy, LcyB, CrtZ-2, and Ccs determined by qRT-PCR. There were unique carotenoid profiles as well as distinct patterns of transcription of carotenogenic enzymes within the seven orange-coloured cultivars. In one cultivar, ‘Fogo’, carrying the mutant ccs-3 allele, transcripts were detected for this gene, but no CCS protein accumulated. The premature stop termination in ccs-3 prevented expression of the biosynthetic activity to synthesize the capsanthin and capsorubin forms of carotenoids. In two other orange-coloured cultivars, ‘Orange Grande’ and ‘Oriole’, both with wild-type versions of all four carotenogenic enzymes, no transcripts for Ccs were detected and no red pigments accumulated. Finally, in a third case, the orange-coloured cultivar, Canary, transcripts for all four of the wild-type carotenogenic enzymes were readily detected yet no CCS protein appeared to accumulate and no red carotenoids were synthesized. In the past, mutations in Psy and Ccs have been identified as the loci controlling colour in the fruit. Now there is evidence that a non-structural gene may control colour development in Capsicum.

There has been an increased use of medical Cannabis in the United States of America as more states legalize its use. Complete chemical analyses of this material can vary considerably between producers and is often not fully provided to consumers. As phytochemists in a state with legal medical Cannabis we sought to characterize the accumulation of phytochemicals in material grown by licensed commercial producers. We report the development of a simple extraction and analysis method, amenable to use by commercial laboratories for the detection and quantification of both cannabinoids and terpenoids. Through analysis of developing flowers on plants, we can identify sources of variability of floral metabolites due to flower maturity and position on the plant. The terpenoid composition varied by accession and was used to cluster cannabis strains into specific types. Inclusion of terpenoids with cannabinoids in the analysis of medical cannabis should be encouraged, as both of these classes of compounds could play a role in the beneficial medical effects of different cannabis strains.

No abstract