Molecular and biochemical identification of inositol 1,3,4,5,6-pentakisphosphate 2-kinase encoding mRNA variants in castor bean (Ricinus communis L.) seeds

Abstract

During seed development, phytic acid (PA) associated with mineral cations is stored as phytin and mobilized following germination in support of seedling growth. Two parallel biosynthetic pathways for PA have been proposed; yet the pathway is still poorly understood in terms of its regulation and the enzymes involved. Here, the castor bean (Ricinus communis L.) gene for inositol 1,3,4,5,6-pentakisphosphate 2-kinase (RcIPK1) has been identified. This encodes the enzyme implicated in catalyzing the final reaction in PA biosynthesis, and its expression is enhanced in isolated germinated embryos by application of phosphate and myo-inositol (Ins). Even though only one copy of the RcIPK1 gene is present in the genome, numerous RNA variants are present, most likely due to alternative splicing. These are translated into six closely related protein isoforms according to in silico analysis. Functional analyses using yeast ipk1Δ revealed that only three of the mRNA variants can rescue a temperature-sensitive growth phenotype of this strain. High-performance liquid chromatography (HPLC) analysis of the synthesized inositol phosphates demonstrated that the ability to complement the missing yeast IPK1 enzyme is associated with the production of enzyme activity. The three active isoforms possess unique conserved motifs important for IPK1 catalytic activity.

Fingerprinting of volatile organic compounds for quick assessment of vigour status of seeds

“…Developing seeds accumulate storage reserves such as carbohydrates, lipids and storage proteins. Subsequent to seed imbibition, the seed germination process is triggered and seeds reserves are mobilized by the action of hydrolytic enzymes (Stotzky and Schenck, 1976) so as to provide the essential energy for seedling growth until it becomes photoautotrophic (Yu et al, 2014). Stotzky and Schenck (1976) indicated that metabolic changes that occur in germinating seeds liberate VOCs, corresponding to the storage reserves present in the seeds.…”

Isolation and Identification of Bacillus Cereus and Escherichia coli from Food Sample Sold Within, Kaduna Town

“…Although most strains of E. coli have not been associated with disease condition, some serotypes have been implicated in serious food poisoning, following ingestion of contaminated food substances. The harmless strains are part of the normal flora of the gut, and can benefit their hosts by producing vitamin K 2 , and preventing colonization of the intestine by pathogenic bacteria [6]. E. coli is expelled into the environment with fecal matter and grows massively in the fecal matter under aerobic conditions for 3 days, but its numbers decline slowly afterwards.…”

Production of single cell protein (SCP) and essentials amino acids from Candida utilis FMJ12 by solid state fermentation using mango waste supplemented with nitrogen sources

“…It has many advantages, such as high product yield with little risk of bacterial contamination, extended stability of products, low wastewater generation and low production costs (Zhao et al, 2008;Barrios-Gonzalez, 2012). SSF has received more interest from researchers and has been applied in various areas, such as biotransformation of crops and crop residues for microbial preparation, nutritional enrichment (Singhania et al, 2009) and production of a range of high value-added products (Quevedo-Hidalgo et al, 2013;Yu et al, 2014). Fermentative production of amino acids in the million-ton-scale has shaped modern biotechnology and its markets continue to grow steadily Somda et al 717 (Wendisch et al, 2016).…”