The beneficial effect of aluminium and the role of citrate in Al accumulation in Melastoma malabathricum

* Here we investigated the beneficial effect of aluminium (Al) on the development of the Al accumulating plant Melastoma malabathricum. * Seedlings of M. malabathricum were cultivated in a nutrient solution containing 0.5 mM Al and compared with barley (Hordeum vulgare). In addition, roots of M. malabathricum were divided into one part growing in a nutrient solution, and the other part growing in a calcium solution. Al (0.5 mM) was applied to either solution. * Al-induced improvements of the root activity contributed to a growth enhancement in M. malabathricum. Al exposure without nutrients did not increase root growth and Al accumulation in the leaves. The beneficial effect, however, was induced by the combination of Al and nutrients. * We suggest that without nutrients roots are not able to synthesize an adequate amount of citrate that is required for transporting Al to the leaves. High Al levels in the plant tissues and/or an interaction of Al with particular nutrient elements in the apoplast of root cells appear to be essential to exert the beneficial effect of Al.     

Complete Chloroplast Genome Sequence of <Emphasis Type="Italic">Glycine max</Emphasis> and Comparative Analyses with other Legume Genomes

Lack of complete chloroplast genome sequences is still one of the major limitations to extending chloroplast genetic engineering technology to useful crops. Therefore, we sequenced the soybean chloroplast genome and compared it to the other completely sequenced legumes, Lotus and Medicago. The chloroplast genome of Glycine is 152,218 basepairs (bp) in length, including a pair of inverted repeats of 25,574 bp of identical sequence separated by a small single copy region of 17,895 bp and a large single copy region of 83,175 bp. The genome contains 111 unique genes, and 19 of these are duplicated in the inverted repeat (IR). Comparisons of Glycine, Lotus and Medicago confirm the organization of legume chloroplast genomes based on previous studies. Gene content of the three legumes is nearly identical. The rpl22 gene is missing from all three legumes, and Medicago is missing rps16 and one copy of the IR. Gene order in Glycine, Lotus, and Medicago differs from the usual gene order for angiosperm chloroplast genomes by the presence of a single, large inversion of 51 kilobases (kb). Detailed analyses of repeated sequences indicate that many of the Glycine repeats that are located in the intergenic spacer regions and introns occur in the same location in the other legumes and in Arabidopsis, suggesting that they may play some functional role. The presence of small repeats of psbA and rbcL in legumes that have lost one copy of the IR indicate that this loss has only occurred once during the evolutionary history of legumes.     

Comparative methods for multiplex analysis of cytokine protein expression in plasma of lipopolysaccharide-treated mice

Changes in circulating cytokines might serve as predictors of compound-evoked inflammatory responses. CD-1 mice were treated with lipopolysaccharide (LPS; 0.2 ml of 0.25 mg/ml, intraperitoneal) for subsequent expression measurement of plasma cytokine protein expression at 24-h post-treatment using multiple antibody Western blot, and at both 2-h and 24-h post-treatment using antibody array and suspension bead array. Antibody array provided a semi-qualitative assessment and suggested significantly increased expression of GCSF at 2-h post-treatment and GCSF, IL-6, IL-12, MCP-1, MCP-5, RANTES and sTNFR1 at 24-h post-treatment. Densitometric analysis of multiple antibody Western blots provided a semi-quantitative assessment and indicated significantly increased expression of IL-6, IL-12, IL-17, GCSF, eotaxin, and MCP-2 at 24-h post-treatment. The suspension bead array yielded statistically significant cytokine protein expression increases for IL-6, IL-10, IFNgamma and TNFalpha at both 2-h and 24-h post-treatments, while significant expression at 24-h post-treatment only was noted for IL-1beta, IL-5, IL-12 and GM-CSF. Suspension bead array provided the greatest range of detection, revealing subtle increased expression of GM-CSF, IL-1beta, IL-5, IL-10, TNFalpha and IFNgamma at 24-h post-treatment, not detected by antibody array or multiple antibody Western blot. Suspension bead array proved to be the best method for detection of LPS-evoked changes in plasma cytokine levels.     

Aphid parasitoid complex in potato in the context of IPM in Belgium

Parasitic hymenoptera of potato aphids were collected and identified in 2000 and 2001 in 11 potato fields in Belgium. Nine Aphidiidae species, parasiting seven aphid species, were found: Aphidius ervi, Aphidius matricariae, Aphidius picipes, Binodoxys angelicae, Diaeretiella rapae, Praon abjectum, Praon gallicium, Praon volucre and Toxares deltiger. A. ervi and A. picipes were the dominant and sub-dominant species, with 54% and 28% of the primary parasite collected, respectively. Both species and T. deltiger were found on Aphis nasturti, Aulacorthum solani, Macrosiphum euphorbiae and Myzus persicae, the four most important aphid potato in Belgium. Parasitism rate of A. nasturtii and, to a lesser extent, M. euphorbiae was low compared to A. solani and M. persicae. Parasitism of A. solani was particularly high, with 63.5% in 2000 and 89.2% in 2001, and this species was the preferred host of several Aphidiid species. The abundance of alternative hosts as other crops pest aphids or non-pest aphids on wild plants in agroecosystems could explains the efficacy of these species. The biological control of A. nasturtii and M. euphorbiae by parasitic hymenoptera was poorer, and several studies need to be undertaken to find suitable parasitic hymenoptera species effective on these aphids and agro-environmental measures able to promote them.     

MicroRNAs: a developing story

Considering the intense genetic efforts applied to understanding development, it is surprising that a relatively large class of regulatory genes has newly surfaced. The first microRNA gene and its developmental role were described more than ten years ago, but only recently have we fully appreciated the broad and abundant presence of such genes. MicroRNAs are approximately 22 nucleotide RNAs that use antisense complementarity to inhibit expression of specific mRNAs. Recent studies of restricted expression patterns and functional roles have implicated specific microRNAs in complex genetic pathways regulating embryogenesis, hematopoiesis, neuronal differentiation and Hox-mediated development.     

Estrogen receptor beta selective ligands: discovery and SAR of novel heterocyclic ligands

A series of ligands with varying heterocyclic cores and substituents that display a range of selectivity’s (up to >100x) for ER-β over ER- are reported.     

Discovery of novel conformationally restricted diazocan peptidomimetics as inhibitors of interleukin-1beta synthesis

A novel diazocan containing dipeptide mimetic was synthesized via reductive N-N bond cleavage of a pyrazolidino-pyrazolidine using Raney-Ni and evaluated as an ICE inhibitor. This versatile 8-membered ring containing scaffold possesses an N-5 ring nitrogen that was used to explore structure-activity relationships in a cell-based assay measuring inhibition of interleukin-1beta.     

Orally bioavailable highly potent HIV protease inhibitors against PI-resistant virus

Efforts directed to identifying potent HIV protease inhibitors (PI) have yielded a class of compounds that are not only very active against wild-type (NL4-3) HIV virus but also very potent against a panel of PI-resistant viral isolates. Chemistry and biology are described.