Modulation of kernel storage proteins in grain sorghum (Sorghum bicolor (L.) Moench)

Sorghum prolamins, termed kafirins, are categorized into subgroups α, β, and γ. The kafirins are co‐translationally translocated to the endoplasmic reticulum (ER) where they are assembled into discrete protein bodies that tend to be poorly digestible with low functionality in food and feed applications. As a means to address the issues surrounding functionality and digestibility in sorghum, we employed a biotechnology approach that is designed to alter protein body structure, with the concomitant synthesis of a co‐protein in the endosperm fraction of the grain. Wherein perturbation of protein body architecture may provide a route to impact digestibility by reducing disulphide bonds about the periphery of the body, while synthesis of a co‐protein, with known functionality attributes, theoretically could impact structure of the protein body through direct association and/or augment end‐use applications of sorghum flour by stabilizing ß‐sheet formation of the kafirins in sorghum dough preparations. This in turn may improve viscoelasticity of sorghum dough. To this end, we report here on the molecular and phenotypic characterizations of transgenic sorghum events that are down‐regulated in γ‐ and the 29‐kDa α‐kafirins and the expression of a wheat Dy10/Dx 5 hybrid high‐molecular weight glutenin protein. The results demonstrate that down‐regulation of γ‐kafirin alone does not alter protein body formation or impacts protein digestibility of cooked flour samples. However, reduction in accumulation of a predicted 29‐kDa α‐kafirin alters the morphology of protein body and enhances protein digestibility in both raw and cooked samples.     

The baseline distribution of malaria in the initial phase of elimination in Sabang Municipality, Aceh Province, Indonesia

ABSTRACT: BACKGROUND: Sabang Municipality, in Aceh Province, Indonesia, plans to initiate a malaria elimination programme in 2013. A baseline survey of the distribution of malaria in the municipality was conducted to lay the foundations for an evidence-based programme and to assess the island's readiness to begin the elimination process. METHODS: The entire population of the municipality was screened for malaria infection and G6PD deficiency. Specimens collected included blood slides, blots and tubes for selected households. Results and Discussion Samples were collected from 16,229 residents. Microscopic examination of the blood smears revealed 12 malaria infections; 10 with Plasmodium falciparum and 2 with Plasmodium vivax. To confirm the parasite prevalence, polymerase chain reaction (PCR) diagnosis was performed on the entire positive cases by microscopy and randomized 10% of the microscopically negative blood samples. PCR revealed an additional 11 subjects with malaria; one P. falciparum infection from the village of Paya Keunekai, and nine P. vivax infections and one mixed P. falciparum/P. vivax infection from the village of Batee Shok. The overall slide positivity rate was 0.074% (CI 95%: 0.070 - 0.078) and PCR corrected prevalence 0,590% (CI 95%: 0.582 - 0.597). Analysis of 937 blood samples for G6PD deficiency revealed two subjects (0.2%) of deficient G6PD. Analysis of several genes of the parasite, such as Pfdhfr, Pfdhps, Pfmdr1, Pfcrt, Pfmsp1, Pfmsp2, Pvdhfr, Pvdhps, Pvmdr1 and host gene, such as G6PD gene revealed that both P. falciparum and P. vivax carried the mutation associated with chloroquine resistance. CONCLUSION: Malariometric and host genetic analysis indicated that there is a low prevalence of both malaria and G6PD deficiency in the population of Sabang Municipality. Nevertheless, malaria cases were clustered in three rural villages and efforts for malaria elimination in Sabang should be particularly focused on those three villages.     

Genetic analysis of the effect of zinc deficiency on Arabidopsis growth and mineral concentrations

Aims

Zinc deficiency is a common micronutrient deficiency in plants growing in many different regions of the world and is associated with disturbances in uptake and accumulation of mineral nutrients. Despite many published data on physiological factors affecting ion accumulation in Zn deficient plants, there is very little information about the genetic factors underlying this. We aim to identify genetic loci involved in mineral accumulation and plant performance under Zn deficiency.

Methods

Genetic loci were identified using the genetically segregating Ler × Cvi recombinant inbred line (RIL) population grown under Zn deficient conditions. Lines were analysed for the concentrations of Zn, Fe, Mn, K, Ca, Mg, P, Cu, S and Al in shoot dry matter. The same was done for the same lines grown under Zn sufficient conditions.

Results

We found considerable heritable variation for most mineral concentrations. In general, there was a positive correlation between mineral concentrations. For Zn only condition-dependent QTLs were identified, while for most other mineral concentrations both condition-dependent and -independent QTLs were identified. Several QTLs co-localize, including co-localization to loci controlling shoot biomass and to mineral concentration loci found previously in this and other RIL populations.

Conclusions

There are different genetic loci controlling Zn accumulation under deficient and sufficient Zn supply. Only for few minerals, their accumulation is controlled by Zn-supply-specific loci.     

The chloroplast triggers developmental reprogramming when mutS HOMOLOG1 is suppressed in plants

Multicellular eukaryotes demonstrate nongenetic, heritable phenotypic versatility in their adaptation to environmental changes. This inclusive inheritance is composed of interacting epigenetic, maternal, and environmental factors. Yet-unidentified maternal effects can have a pronounced influence on plant phenotypic adaptation to changing environmental conditions. To explore the control of phenotypy in higher plants, we examined the effect of a single plant nuclear gene on the expression and transmission of phenotypic variability in Arabidopsis (Arabidopsis thaliana). MutS HOMOLOG1 (MSH1) is a plant-specific nuclear gene product that functions in both mitochondria and plastids to maintain genome stability. RNA interference suppression of the gene elicits strikingly similar programmed changes in plant growth pattern in six different plant species, changes subsequently heritable independent of the RNA interference transgene. The altered phenotypes reflect multiple pathways that are known to participate in adaptation, including altered phytohormone effects for dwarfed growth and reduced internode elongation, enhanced branching, reduced stomatal density, altered leaf morphology, delayed flowering, and extended juvenility, with conversion to perennial growth pattern in short days. Some of these effects are partially reversed with the application of gibberellic acid. Genetic hemicomplementation experiments show that this phenotypic plasticity derives from changes in chloroplast state. Our results suggest that suppression of MSH1, which occurs under several forms of abiotic stress, triggers a plastidial response process that involves nongenetic inheritance.     

Response of Different Antibiotic Resistant Group of Streptococcus pyogenes to Environmental Stresses

Streptococcus species is considered as an important pathogen for human and animals. The antibiotic resistance mechanism in this species is continuously increased. On the other side, the tolerance of environmental stresses play an effective role in the severity of many streptococcal causative disease. In this study we assayed survey on the causative agents of pharyngitis and tonsillitis patients. The predominant causative strain was Streptococcus pyogenes with 93 % isolating ratio frequency. The other pathogenic species were S. agalactia 5.3 % and S. pneumonia 1.7 %. According to the antibiotic resistant test the S. pyogenes isolates were classified into six different groups. A selected strain from each antibiotic resistant group was tested for tolerance of a restrictive environmental factors. The variations of the environmental niches of isolates were in consistence with their antibiotic resistant variation.     

Notes on the occurrence of the tropical eel Anguilla bicolor bicolor in Peninsular Malaysia, Malaysia

Previous studies indicated that a tropical freshwater eel Anguilla bicolor bicolor occurs in Africa, India, Sri Lanka, Bangladesh, Myanmar, Indonesia and Australia, but an intensive survey has indicated an extended distribution range for the species into Peninsular Malaysia. Thus, A. b. bicolor is a native subspecies of Malaysia.     

Toddaculin, a natural coumarin from Toddalia asiatica, induces differentiation and apoptosis in U-937 leukemic cells

Chemotherapeutics represent the main approach for the treatment of leukemia. However, the occurrence of adverse side effects and the complete lack of effectiveness in some cases make it necessary to develop new drugs. As part of our screening program to evaluate the potential chemotherapeutic effect of natural coumarins, we investigated the anti-leukemic activities of a series of six prenylated coumarins isolated from the stem bark of Toddalia asiatica (Rutaceae). Among these, 6-(3-methyl-2-butenyl)-5,7-dimethoxycoumarin (toddaculin) displayed the most potent cytotoxic and anti-proliferative effects in U-937 cells. To determine whether these effects resulted from induction of cell death or differentiation, we further evaluated the expression of several apoptosis and maturation markers. Interestingly, while toddaculin at 250 μM was able to induce apoptosis in U-937 cells, involving decreased phosphorylation levels of ERK and Akt, 50 μM toddaculin exerted differentiating effects, inducing both the capacity of U-937 cells to reduce NBT and the expression of differentiation markers CD88 and CD11b, but no change in p-Akt or p-ERK levels. Taken together, these findings indicate that toddaculin displays a dual effect as a cell differentiating agent and apoptosis inducer in U-937 cells, suggesting it may serve as a pharmacological prototype for the development of novel anti-leukemic agents.     

Allele and genotype frequencies of the polymorphic cytochrome P450 genes (CYP1A1, CYP3A4, CYP3A5, CYP2C9 and CYP2C19) in the Jordanian population

Drug metabolizing enzymes participate in the neutralizing of xenobiotics and biotransformation of drugs. Human cytochrome P450, particularly CYP1A1, CYP2C9, CYP2C19, CYP3A4 and CYP3A5, play an important role in drug metabolism. The genes encoding the CYP enzymes are polymorphic, and extensive data have shown that certain alleles confer reduced enzymatic function. The goal of this study was to determine the frequencies of important allelic variants of CYP1A1, CYP2C9, CYP2C19, CYP3A4 and CYP3A5 in the Jordanian population and compare them with the frequency in other ethnic groups. Genotyping of CYP1A1(m1 and m2), CYP2C9 (*2 and *3), CYP2C19 (*2 and *3), CYP3A4*5, CYP3A5 (*3 and *6), was carried out on Jordanian subjects. Different variants allele were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). CYP1A1 allele frequencies in 290 subjects were 0.764 for CYP1A1*1, 0.165 for CYP1A1*2A and 0.071 for CYP1A1*2C. CYP2C9 allele frequencies in 263 subjects were 0.797 for CYP2C9*1, 0.135 for CYP2C9*2 and 0.068 for CYP2C9*3. For CYP2C19, the frequencies of the wild type (CYP2C19*1) and the nonfunctional (*2 and *3) alleles were 0.877, 0.123 and 0, respectively. Five subjects (3.16?%) were homozygous for *2/*2. Regarding CYP3A4*1B, only 12 subjects out of 173 subjects (6.9?%) were heterozygote with none were mutant for this polymorphism. With respect to CYP3A5, 229 were analyzed, frequencies of CYP3A5*1,*3 and *6 were 0.071, 0.925 and 0.0022, respectively. Comparing our data with that obtained in several Caucasian, African-American and Asian populations, Jordanians are most similar to Caucasians with regard to allelic frequencies of the tested variants of CYP1A1, CYP2C9, CYP2C19, CYP3A4 and CYP3A5.