A Study in Scaffold Hopping: Discovery and Optimization of Thiazolopyridines as Potent Herbicides That Inhibit Acyl-ACP Thioesterase.

In the search for new chemical entities that can control resistant weeds by addressing novel modes of action (MoAs), we were interested in further exploring a compound class that contained a 1,8-naphthyridine core. By leveraging scaffold hopping methodologies, we were able to discover the new thiazolopyridine compound class that act as potent herbicidal molecules. Further biochemical investigations allowed us to identify that the thiazolopyridines inhibit acyl-acyl carrier protein (ACP) thioesterase (FAT), with this being further confirmed via an X-ray cocrystal structure.

Expression levels of inositol phosphorylceramide synthase modulate plant responses to biotic and abiotic stress in Arabidopsis thaliana.

This research was undertaken to investigate the global role of the plant inositol phosphorylceramide synthase (IPCS), a non-mammalian enzyme previously shown to be associated with the pathogen response. RNA-Seq analyses demonstrated that over-expression of inositol phosphorylceramide synthase isoforms AtIPCS1, 2 or 3 in Arabidopsis thaliana resulted in the down-regulation of genes involved in plant response to pathogens. In addition, genes associated with the abiotic stress response to salinity, cold and drought were found to be similarly down-regulated.

PALE CRESS binds to plastid RNAs and facilitates the biogenesis of the 50S ribosomal subunit.

The plant-specific PALE CRESS (PAC) protein has previously been shown to be essential for photoautotrophic growth. Here we further investigated the molecular function of the PAC protein. PAC localizes to plastid nucleoids and forms large proteinaceous and RNA-containing megadalton complexes.

A gene stacking approach leads to engineered plants with highly increased galactan levels in Arabidopsis.

Background: Engineering of plants with a composition of lignocellulosic biomass that is more suitable for downstream processing is of high interest for next-generation biofuel production. Lignocellulosic biomass contains a high proportion of pentose residues, which are more difficult to convert into fuels than hexoses. Therefore, increasing the hexose/pentose ratio in biomass is one approach for biomass improvement.

Complex RNA metabolism in the chloroplast: an update on the psbB operon.

Expression of most plastid genes involves multiple post-transcriptional processing events, such as splicing, editing, and intercistronic processing. The latter involves the formation of mono-, di-, and multicistronic transcripts, which can further be regulated by differential stability and expression. The plastid pentacistronic psbB transcription unit has been well characterized in vascular plants.

RHON1 is a novel ribonucleic acid-binding protein that supports RNase E function in the Arabidopsis chloroplast.

The Arabidopsis endonuclease RNase E (RNE) is localized in the chloroplast and is involved in processing of plastid ribonucleic acids (RNAs). By expression of a tandem affinity purification-tagged version of the plastid RNE in the Arabidopsis rne mutant background in combination with mass spectrometry, we identified the novel vascular plant-specific and co-regulated interaction partner of RNE, designated RHON1. RHON1 is essential for photoautotrophic growth and together with RNE forms a distinct ∼800 kDa complex.

The cutting crew - ribonucleases are key players in the control of plastid gene expression.

Chloroplast biogenesis requires constant adjustment of RNA homeostasis under conditions of on-going developmental and environmental change and its regulation is achieved mainly by post-transcriptional control mechanisms mediated by various nucleus-encoded ribonucleases. More than 180 ribonucleases are annotated in Arabidopsis, but only 17 are predicted to localize to the chloroplast. Although different ribonucleases act at different RNA target sites in vivo, most nucleases that attack RNA are thought to lack intrinsic cleavage specificity and show non-specific activity in vitro.

Recruitment of a ribosomal release factor for light- and stress-dependent regulation of petB transcript stability in Arabidopsis chloroplasts.

Land plant genomes encode four functional ribosomal peptide chain release factors (Prf) of eubacterial origin, two (PrfA and PrfB homologs) for each endosymbiotic organelle. Formerly, we have shown that the Arabidopsis thaliana chloroplast-localized PrfB homolog, PrfB1, is required not only for termination of translation but also for stabilization of UGA stop codon-containing chloroplast transcripts. A previously undiscovered PrfB-like protein, PrfB3, is localized to the chloroplast stroma in a petB RNA-containing complex and found only in vascular plants.

Construction, database integration, and application of an Oenothera EST library.

Coevolution of cellular genetic compartments is a fundamental aspect in eukaryotic genome evolution that becomes apparent in serious developmental disturbances after interspecific organelle exchanges. The genus Oenothera represents a unique, at present the only available, resource to study the role of the compartmentalized plant genome in diversification of populations and speciation processes. An integrated approach involving cDNA cloning, EST sequencing, and bioinformatic data mining was chosen using Oenothera elata with the genetic constitution nuclear genome AA with plastome type I.