Biosynthesis of capsinoid is controlled by the Pun1 locus in pepper

Pungency in pepper (Capsicum annuum L.) has unique characteristics due to the alkaloid compound group, capsaicinoids, which includes capsaicin. Although capsaicinoids have been proved to have pharmacological and physiological effects on human health, the application of capsaicinoids has been limited because of their pungency. Capsinoids found in non-pungent peppers share closely related structures with capsaicinoids and show similar biological effects. Previous studies demonstrated that mutations in the p-AMT gene were related to the production of capsinoids; however, the pathway of capsinoid synthesis has not yet been fully elucidated. In this study, we performed genetic analysis to determine the mechanism of capsinoid synthesis using a F6 recombinant inbred line population. In this population, the presence/absence of capsinoids co-segregated with the genotype of the Pun1 locus, without exception. In addition, we screened the patterns of capsinoid synthesis and the correlation between the Pun1 locus and capsinoid synthesis in p-AMT mutant accessions. In Capsicum germplasms, we selected amino-acid-substituted mutants in the PLP binding domain of the p-AMT gene. Capsinoids were not synthesized with the recessive pun1 gene, regardless of the p-AMT genotype, and no relationship was found between p-AMT mutant type and capsinoid content. We concluded that the Pun1 gene, which is responsible for capsaicinoid synthesis, also controls capsinoid synthesis.     

Development of Capsicum EST–SSR markers for species identification and in silico mapping onto the tomato genome sequence

Capsicum spp. are widely cultivated for use as vegetables and spices. The Kihara Institute for Biological Research, Yokohama City University, Japan, has stocks of approximately 800 lines of Capsicum spp. collected from various regions of Central and South America, the regions of origin for Capsicum spp. In this study, 5,751 primer pairs for simple sequence repeat markers, based on 118,060 publicly available sequences of expressed sequence tags of Capsicum annuum, were designed and subjected to a similarity search against the genomic sequence of tomato, a model Solanaceae species. Nucleotide sequences spanning 2,245 C. annuum markers were successfully mapped onto the tomato genome, and 96 of these, which spanned the entire tomato genome, were selected for further analysis. In genotyping analysis, 60 out of the 77 markers that produced specific DNA amplicons showed polymorphism among the Capsicum lines examined. On the basis of the resulting data, the 192 tested lines were grouped into five main clusters. The additional sequencing analysis of the plastid genes, matK and rbcL, divided the resources into three groups. As a result, 19 marker loci exhibited genotypes specific to species and cluster, suggesting that the DNA markers are useful for species identification. Information on the DNA markers will contribute to Capsicum genetics, genomics, and breeding.     

Fine mapping of Grh1, a major gene associated with antibiosis to green rice leafhopper in rice

Green rice leafhopper (GRH, Nephotettix cincticeps Uhler) is one of the insect pests that damage cultivated rice in East Asia. GRH also transmits viruses such as rice dwarf virus. The mortality of GRH nymphs is high in rice cultivar Shingwang, indicating that Shingwang is resistant to GRH. Genetic analyses were performed to map GRH resistance in Shingwang using F2 and F3 populations derived from a cross between a GRH-resistant near-isogenic line (NIL-IS60) from Shingwang and recurrent parent Ilpum. Resistance to GRH in Shingwang was found to be controlled by a single dominant gene (Grh1) mapped within an approximately 670-kb region between 8.10 and 8.77 Mb on the short arm of chromosome 5. Genotypes with three simple sequence repeat markers (RM18166, RM516, and RM18171) and one indel marker (Indel 15040) co-segregated with GRH resistance controlled by the Grh1 locus. A detailed map of the Grh1 locus will facilitate marker-assisted selection of resistance to GRH in rice breeding.     

Relationship between endospore viability and insecticidal potency of Bacillus thuringiensis subsp. aizawai NT0423

Bioassay can be used for analysis of the biological potency of Bacillus thuringiensis (Bt) in fermentation and formulation but requires precise scheduling and several repetitions. Alternatively, this work explored if the endospore counting could be used to predict the potency of Bt technical powder. Analyses of Bt technical powers provided a strong linear relationship (r = 0.971) between the number of viable endospores and the potency of the technical powder against second instar Plutella xylostella (L.) larvae. Next, a Bt wettable powder formulation was stored at 25 and 40 °C for 12 weeks to investigate the influence of storage temperature on the prediction of insecticidal potency based on the counting. At 25 °C storage, the insecticidal potency could be predicted based on the counting, but at 40 °C the predicted insecticidal potency was much lower than the measured potency. These results suggest that the NT0423 endospore viability can be used to predict its potency in production, but the relationship may not be the same following the storage at high temperature.     

Direct Targeting of Proteins from the Cytosol to Organelles: The ER versus Endosymbiotic Organelles

In eukaryotic cells consisting of many different types of organelles, targeting of organellar proteins is one of the most fundamental cellular processes. Proteins belonging to the endoplasmic reticulum (ER), chloroplasts and mitochondria are targeted individually from the cytosol to their cognate organelles. As the targeting to these organelles occurs in the cytosol during or after translation, the most crucial aspect is how specific targeting to these three organelles can be achieved without interfering with other targeting pathways. For these organelles, multiple mechanisms are used for targeting proteins, but the exact mechanism used depends on the type of protein and organelle, the location of targeting signals in the protein and the location of the protein in the organelle. In this review, we discuss the various mechanisms involved in protein targeting to the ER, chloroplasts and mitochondria, and how the targeting specificity is determined for these organelles in plant cells .     

The role of disulfide bond in hyperthermophilic endocellulase

The hyperthermophilic endocellulase, EGPh (glycosyl hydrolase family 5) from Pyrococcus horikoshii possesses 4 cysteine residues forming 2 disulfide bonds, as identified by structural analysis. One of the disulfide bonds is located at the proximal region of the active site in EGPh, which exhibits a distinct pattern from that of the thermophilic endocellulase EGAc (glycosyl hydrolase family 5) of Acidothermus cellulolyticus despite the structural similarity between the two endocellulases. The structural similarity between EGPh and EGAc suggests that EGPh possesses a structure suitable for changing the position of the disulfide bond corresponding to that in EGAc. Introduction of this alternative disulfide bond in EGPh, while removing the original disulfide bond, did not result in a loss of enzymatic activity but the EGPh was no longer hyperthermostable. These results suggest that the contribution of disulfide bond to hyperthermostability at temperature higher than 100 °C is restrictive, and that its impact is dependent on the specific structural environment of the hyperthermophilic proteins. The data suggest that the structural position and environment of the disulfide bond has a greater effect on high-temperature thermostability of the enzyme than on the potential energy of the dihedral angle that contributes to disulfide bond cleavage.     

A pilot study of autologous CD34-depleted bone marrow mononuclear cell transplantation via the hepatic artery in five patients with liver failure

Background aimsMany rodent experiments and human studies on stem cell therapy have shown promising therapeutic approaches to liver diseases. We investigated the clinical outcomes of five patients with liver failure of various causes who received autologous CD34-depleted bone marrow-derived mononuclear cell (BM-MNC) transplantation, including mesenchymal stromal cells, through the hepatic artery.MethodsCD34-depleted BM-MNCs were obtained from five patients waiting for liver transplantation by bone marrow aspiration and using the CliniMACS CD34 Reagent System (Miltenyi Biotech, Bergisch Gladbach, Germany), and autologous hepatic artery infusion was performed. The causes of hepatic decompensation were hepatitis B virus (HBV), hepatitis C virus (HCV), propylthiouracil-induced toxic hepatitis and Wilson disease.ResultsSerum albumin levels improved 1 week after transplantation from 2.8 g/dL, 2.4 g/dL, 2.7 g/dL and 1.9 g/dL to 3.3 g/dL, 3.1 g/dL, 2.8 g/dL and 2.6 g/dL. Transient liver elastography data showed some change from 65 kPa, 33 kPa, 34.8 kPa and undetectable to 46.4 kPa, 19.8 kPa, 29.1 kPa and 67.8 kPa at 4 weeks after transplantation in a patient with Wilson disease, a patient with HCV, and two patients with HBV. Ascites decreased in two patients. One of the patients with HBV underwent liver transplantation 4 months after the infusion, and the hepatic progenitor markers (cytokeratin [CD]-7, CD-8, CD-9, CD-18, CD-19, c-Kit and epithelial cell adhesion molecule [EpCAM]) were highly expressed in the explanted liver.ConclusionsSerum albumin levels, liver stiffness, liver volume, subjective healthiness and quality of life improved in the study patients. Although these findings were observed in a small population, the results may suggest a promising future for autologous CD34-depleted BM-MNC transplantation as a bridge to liver transplantation in patients with liver failure.     

Acute exacerbations in patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrosing interstitial lung disease that primarily affects older adults. Median survival after diagnosis is 2–3 years. The clinical course of IPF may include periods of acute deterioration in respiratory function, which are termed acute exacerbations of IPF (AEx-IPF) when a cause cannot be identified. AEx-IPF may represent a sudden acceleration of the underlying disease process of IPF, or a biologically distinct pathological process that is clinically undiagnosed. An AEx-IPF can occur at any time during the course of IPF and may be the presenting manifestation. The incidence of AEx-IPF is hard to establish due to variation in the methodology used to assess AEx-IPF in different studies, but AEx-IPF are believed to occur in between 5 and 10% of patients with IPF every year. Risk factors for AEx-IPF are unclear, but there is evidence that poorer lung function increases the risk of an AEx-IPF and reduces the chances of a patient surviving an AEx-IPF. The presence of comorbidities such as gastroesophageal reflux disease (GERD) and pulmonary hypertension may also increase the risk of an AEx-IPF. AEx-IPF are associated with high morbidity and mortality. Patients who experience an AEx-IPF show a worsened prognosis and AEx-IPF are believed to reflect disease progression in IPF. Current treatments for AEx-IPF have only limited data to support their effectiveness. The latest international treatment guidelines state that supportive care remains the mainstay of treatment for AEx-IPF, but also give a weak recommendation for the treatment of the majority of patients with AEx-IPF with corticosteroids. There is emerging evidence from clinical trials of investigational therapies that chronic treatment of IPF may reduce the incidence of AEx-IPF. Additional clinical trials investigating this are underway.