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Grass crops are the most important sources of human nutrition, and their improvement is centrally important for meeting the challenges of sustainable agriculture, for feeding the world's population and for developing renewable supplies of fuel and industrial products. We describe the complete sequence of the compact genome of Brachypodium distachyon (Brachypodium) the first pooid grass to be sequenced. We demonstrate the many favorable characteristics of Brachypodium as an experimental system and show how it can be used to navigate the large and complex genomes of closely related grasses. The functional genomics and other experimental resources that are being developed will provide a key resource for improving food and forage crops, in particular wheat, barley and forage grasses, and for establishing new grass crops for sustainable energy production.

The predominant mechanism for controlling gene expression in eukaryotes appears to be regulation at the transcriptional level. Transcriptional regulation of gene expression is mediated by transcription factors, which activate or repress transcription. These activators and repressors act through several mechanisms (including DNA–protein interactions, protein–protein interactions and modification of the chromatin structure) and are themselves regulated in a variety of ways. Using various modes, a single transcription factor can influence the transcription of different target genes. Recent research on these regulatory mechanisms in plants has provided insight into the underlying processes.

Summary A UDP-glucose pyrophosphorylase (UDPG-PPase, E.C. 2.7.7.9) cDNA from potato ( Solanum tuberosum L.) tuber was cloned and sequenced. RNA analysis revealed expression in all tissues of the developing potato plant and that UDPG-PPase RNA could be induced by high sucrose treatments to exised leaves. In tubers, a coordinated expression of UDPG-PPase RNA with the RNA levels of several additional enzymes involved in the conversion of sucrose to starch was observed at harvest. Tubers of potato plants transformed with a patatin promoter-antisense-UDPG-PPase cDNA fusion were stored for 0, 1, 3 and 6 weeks at 4°C and 12°C. The tubers expressed various levels of antisense and sense UDPG-PPase RNA. The maximum antisense-mediated inhibition of UDPG-PPase enzyme activity was 30%, and this inhibition was maintained throughout the six weeks of storage at both 4°C and 12°C. No significant changes could consistently be found in Glc-1-P, Glc-6-P, Fru-6-P, UDP-Glc, glucose or fructose content in the transgenic tubers compared to wild type tubers. However, a statistically significant decrease in sucrose content was associated with the transgenic reduction of UDPG-PPase activity after 3 and 6weeks of storage.

GARNet, the Genomic Arabidopsis Resource Network, was created to establish UK-based facilities for functional genomic research on Arabidopsis thaliana. In addition, GARNet provides a platform for international Arabidopsis research and for research on other plant species. To use the GARNet facilities apply via the website: http://garnet.arabidopsis.org.uk. All GARNet services and resources are publicly available, and data created using the GARNet resources will be freely distributed via databases held at the Nottingham Arabidopsis Stock Centre and the John Innes Centre.

Uncapped messenger RNAs (mRNAs) encoding calf preprochymosin, chicken prelysozyme, or Escherichia coli beta-glucuronidase (GUS) were synthesized in vitro, with or without a 5'-terminal 67-nucleotide sequence (omega') derived from the untranslated 5'-leader (omega) of tobacco mosaic virus (TMV) RNA. Messenger RNAs were translated in vitro, in messenger-dependent systems derived from rabbit reticulocytes (MDL), wheat-germ (WG) or E. coli (EC). The omega' sequence enhanced expression of each mRNA in almost every translation system. While MDL was the least responsive to omega', this sequence proved particularly efficient in permitting translation of the eukaryotic mRNAs in EC, despite the absence of a consensus Shine-Dalgarno sequence in either the mRNAs or omega'. The local context of the initiation codon (AUG) in two GUS mRNA constructs did not influence the relative enhancement caused by the omega' sequence. These findings extend the utility of omega' as a general enhancer of translation for both prokaryotic and eukaryotic mRNAs in either 80S- or 70S-ribosome-based systems.