Genes for pentatricopeptide repeat (PPR) proteins are found in all eukaryotic genomes analyzed but are particularly abundant in land plants. The majority of analyzed PPR proteins play a role in the processing or translation of organellar RNAs. Few PPR proteins have been studied in detail, and the functional repertoire and mechanisms of action of proteins in the PPR family are poorly understood. Here we analyzed a maize ortholog of the embryo-essential Arabidopsis thaliana gene AtPPR5. A genome-wide analysis of chloroplast RNAs that coimmunoprecipitate with Zea mays PPR5 (ZmPPR5) demonstrated that ZmPPR5 is bound in vivo to the unspliced precursor of trnG-UCC. Null and hypomorphic Zmppr5 insertion mutants are embryo viable but are deficient for chloroplast ribosomes and die as seedlings. These mutants show a dramatic decrease in both spliced and unspliced trnG-UCC RNAs, while the transcription of trnG-UCC is unaffected. These results, together with biochemical data documenting the sequence-specific binding of recombinant PPR5 to the trnG-UCC group II intron, suggest that PPR5 stabilizes the trnG-UCC precursor by directly binding and protecting an endonuclease-sensitive site. These findings add to the evidence that chloroplast-localized PPR proteins that are embryo essential in Arabidopsis typically function in the biogenesis of the plastid translation machinery.
- American Society for Microbiology
- The pentatricopeptide repeat protein ppr5 stabilizes a specific ...
Monitoring hydrocarbons in Bilge water - Case study
The Situation Various processes onboard ships, such as machinery wash-down, maintenance, and leakage, generate oily wastewater. This contaminated water flow collects in the bilge of the ship. Marine diesel, lubricating oils, grease, as well as other contaminants may be present in bilge water. The bilge water is discharged overboard, with oil and grease concentrations in the discharged water limited by national and international regulations.In the United States territorial waters, the U.S. Coast Guard (USCG)...
TOC analyzer for airports
During winter, de-icing processes at airports necessitate storm water and de-icing water management. Especially due to adhesive (sticky) substances, strongly fluctuating concentrations and a lot of chemicals, the monitoring systems itself must be tailor-made to fight this water analysis challenge. LAR `s QuickTOCairport is an application-specific online total organic carbon (TOC) analyzer that meets these tough requirements. The sample is injected via a robot-driven injection system to the oven – without...
How to investigate mercury in the oceans?
Mercury is a highly toxic metal that affects the environment and can endanger people`s health, as a powerful neurotoxin. The combustion of coal, waste and fuel are releasing hundreds of tons of heavy metal into the atmosphere annually, and its sediment enters to soil and water. Mercury measurements are part of the EU project "Global Mercury Observation System". The long-term goal of this project is to create a global system for monitoring of mercury and its compounds. In the process of achieving this goal are...
Analyzer underpins growth of container inspection company
After a career as a customs officer in the Netherlands, Wim van Tienen was well aware of the toxic gas hazards presented by some freight containers, so in 2009 he started a company, Van Tienen Milieuadvies B.V., offering gas analysis and safety advice. The company grew quickly and now employs 23 staff. Wim attributes a large part of this success to the advanced FTIR gas detection and analysis technology upon which the company’s services depend. Background It has been estimated that there are more than 17...
Study: Biological treatments in early production of tomatoes
At Vineland Research and Innovation Centre in Ontario, Plant Pathology Research Technician Travis Cranmer is working to analyze the efficacy of biopesticides against root diseases in hydroponic tomato production. The study’s findings were released at the Canadian Greenhouse Conference in Niagara Falls in October 2016. Cranmer shares some of his conclusions.