Influence of red pepper and capsaicin on body composition and lipogenesis in rats

Inclusion of red pepper or its active principle ‘capsaicin’ in the diet led to a lowering of total lipids, particularly triglycerides in the liver. The total body fat was lowered in animals fed red pepper or capsaicin but not in animals fed paprika powder which had negligible capsaicin content. Hyperlipogensis and hypertriglyceridemia caused by fructose feeding were significantly were decreased in capsaicin-fed animals. Activities of the key lipogenic enzymes were reduced as reflected by decreased lipogenesis.     

Differential callus type formation by auxins and cytokinin in in vitro cultures of pepper (Capsicum annuum L.)

ABSTRACT

Two types of callus were produced by pepper explants cultured in various media containing auxins, the cytokinin 6-benzylaminopurine (BAP) and the auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA). Callus produced on media containing auxins alone was friable, grey-green or green-orange in colour and more compact, whereas when BAP was added to culture media with a low concentration of auxin or when the medium contained TIBA alone, the callus produced was white and very hard. This type of callus was also produced in cultures of older tissues and of young tissues cultured on hormonefree medium. Results are discussed in relation to the role of cytokinins in wounding, phenylpropanoid metabolism and lignin biosynthesis.     

Sensitive Chemiluminescence Enzyme Immunoassay for Vascular Endothelial Growth Factor/Vascular Permeability Factor in Human Serum

A sandwich chemiluminescence enzyme immunoassay for measuring the level of VEGF /VPF in serum was constructed. The detectability of the assay is very low (1.0pg/ml) and the measurable range of the assay was very wide (1–1000 pg/ml). The assay showed that the average level of VEGF /VPF in human sera from healthy blood donors was approximately 19 pg/ml.     

EM复合菌对新疆色素辣椒生长及根际细菌群落的影响

【背景】Effective microorganisms （EM）复合菌在我国农业种植上的应用越来越广泛,但对色素辣椒的促生作用与根际细菌群落结构的影响未见报道。【目的】评估EM复合菌对新疆色素辣椒的促生长作用,并分析其对色素辣椒根际细菌群落组成的影响。【方法】通过随水灌溉方式将EM复合菌接种到色素辣椒根部,在收获期测定辣椒生长指标、土壤养分和酶活活性,明确EM复合菌对辣椒生长和土壤质量的影响;利用16S rRNA基因高通量测序技术测定EM复合菌对辣椒根系细菌群落组成和结构的影响。【结果】与对照组相比,EM复合菌的施用使辣椒株高、鲜重、单个果重和单株结果数分别提高23.89%、85.41%、42.31%和46.04%;土壤中碱解氮和速效磷含量分别提高5.83%和13.39%,土壤中脲酶、蔗糖酶和过氧化物酶的活性分别提高11.47%、9.42%和21.43%;施用EM复合菌显著改变辣椒根际微生物群落的α多样性和β多样性,提高有益菌群变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、芽单胞菌门（Gemmatimonadetes）、放线菌门（Actinobacteria）和厚壁菌门（Firmicutes）的相对丰度,其中变形菌门黄单胞菌科（Xanthomonadaceae）的相对丰度增加119.32%;在属的水平上,施用EM复合菌显著增加了藤黄色杆菌属（Luteitalea）、藤黄单胞菌属（Luteimonas）、鞘脂单胞菌属（Sphingobacterium）和盐单胞菌属（Halomonas）的相对丰度,尤其是藤黄单胞菌属的丰度提高244.17%,同时显著降低黄杆菌属（Flavobacterium）的相对丰度。此外,与土壤理化指标呈正相关的微生物菌群相对丰度也显著升高。【结论】EM复合菌能够通过提高土壤营养成分与酶活活性,调控根系微生物群落结构,富集大量在盐碱地生存能力较强的有益菌群,进而起到促进色素辣椒生长的功效。     

Physiology of pepper fruit and the metabolism of antioxidants: chloroplasts,mitochondria and peroxisomes

Background and Aims Pepper (Capsicum annuum) contains high levels of antioxidants, such as vitamins A and C and flavonoids. However, information on the role of these beneficial compounds in the physiology of pepper fruit remains scarce. Recent studies have shown that antioxidants in ripe pepper fruit play a key role in responses to temperature changes, and the redox state at the time of harvest affects the nutritional value for human consumption. In this paper, the role of antioxidant metabolism of pepper fruit during ripening and in the response to low temperature is addressed, paying particular attention to ascorbate, NADPH and the superoxide dismutase enzymatic system. The participation of chloroplasts, mitochondria and peroxisomes in the ripening process is also investigated.Scope and Results Important changes occur at a subcellular level during ripening of pepper fruit. Chloroplasts turn into chromoplasts, with drastic conversion of their metabolism, and the role of the ascorbate–glutathione cycle is essential. In mitochondria from red fruits, higher ascorbate peroxidase (APX) and Mn-SOD activities are involved in avoiding the accumulation of reactive oxygen species in these organelles during ripening. Peroxisomes, whose antioxidant capacity at fruit ripening is substantially affected, display an atypical metabolic pattern during this physiological stage. In spite of these differences observed in the antioxidative metabolism of mitochondria and peroxisomes, proteomic analysis of these organelles, carried out by 2-D electrophoresis and MALDI-TOF/TOF and provided here for the first time, reveals no changes between the antioxidant metabolism from immature (green) and ripe (red) fruits.Conclusions Taken together, the results show that investigation of molecular and enzymatic antioxidants from cell compartments, especially chloroplasts, mitochondria and peroxisomes, is a useful tool to study the physiology of pepper fruit, particularly in the context of expanding their shelf-life after harvest and in maintaining their nutritional value.     

Plasmid composition and the chpG gene determine the virulence level of Clavibacter capsici natural isolates in pepper

The gram-positive bacterial species Clavibacter capsici causes necrosis and canker in pepper plants. Genomic and functional analyses of C. capsici type strain PF008 have shown that multiple virulence genes exist in its two plasmids. We aimed to identify the key determinants that control the virulence of C. capsici. Pepper leaves inoculated with 54 natural isolates exhibited significant variation in the necrosis. Six isolates showed very low virulence, but their population titres in plants were not significantly different from those of the highly virulent isolates. All six isolates lacked the pCM1_Cc plasmid that carries chpG, which has been shown to be required for virulence and encodes a putative serine protease, but two of them, isolates 1,106 and 1,207, had the intact chpG elsewhere in the genome. Genomic analysis of these two isolates revealed that chpG was located in the pCM2_Cc plasmid, and two highly homologous regions were present next to the chpG locus. The chpG expression in isolate 1,106 was not induced in plants. Introduction of chpG of the PF008 strain into the six low-virulence isolates restored their virulence to that of PF008. Our findings indicate that there are at least three different variant groups of C. capsici and that the plasmid composition and the chpG gene are critical for determining the virulence level. Moreover, our findings also indicate that the virulence level of C. capsici does not directly correlate with bacterial titres in plants.     

Double mutations in eIF4E and eIFiso4E confer recessive resistance to <Emphasis Type="Italic">Chilli veinal mottle virus</Emphasis> in pepper

To evaluate the involvement of translation initiation factors eIF4E and eIFiso4E in Chilli veinai mottle virus (ChiVMV) infection in pepper, we conducted a genetic analysis using a segregating population derived from a cross between Capsicum annuum ‘Dempsey’ containing an eIF4E mutation (pvr1 ² ) and C. annuum ‘Perennial’ containing an eIFiso4E mutation (pvr6). C. annuum ‘Dempsey’ was susceptible and C. annuum ‘Perennial’ was resistant to ChiVMV. All F₁ plants showed resistance, and F₂ individuals segregated in a resistant-susceptible ratio of 166:21, indicating that many resistance loci were involved. Seventy-five F₂ and 329 F₃ plants of 17 families were genotyped with pvr1 ² and pvr6 allele-specific markers, and the genotype data were compared with observed resistance to viral infection. All plants containing homozygous genotypes of both pvr1 ² and pvr6 were resistant to ChiVMV, demonstrating that simultaneous mutations in eIF4E and eIFiso4E confer resistance to ChiVMV in pepper. Genotype analysis of F2 plants revealed that all plants containing homozygous genotypes of both pvr1 ² and pvr6 showed resistance to ChiVMV. In protein-protein interaction experiments, ChiVMV viral genome-linked protein (VPg) interacted with both eIF4E and eIFiso4E. Silencing of eIF4E and eIFiso4E in the VIGS experiment showed reduction in ChiVMV accumulation. These results demonstrated that ChiVMV can use both eIF4E and eIFiso4E for replication, making simultaneous mutations in eIF4E and eIFiso4E necessary to prevent ChiVMV infection in pepper. These authors contributed equally to this work.     

Assessment of Gene Flow from Genetically Modified Anthracnose-Resistant Chili Pepper (Capsicum annuum L.) to a Conventional Crop

We conducted a 2-year field assessment of the gene flow from genetically modified (GM) chili pepper (Capsicum annuum L.), containing the PepEST (pepper esterase) gene, to a non-GM control line “WT512” and two commercial hybrid cultivars, “Manidda” and “Cheongpung Myeongwol (CM).” After seeds were collected from the pollen-recipient non-GM plants, hybrids between them and the GM peppers were screened by a hygromycin assay. PCR with the targeting hpt gene was performed to confirm the presence of transgenes in hygromycin-resistant seedlings. Out of 7,071 “WT512” seeds and 6,854 “Manidda” seeds collected in 2006, eight and 12 hybrids, respectively, were detected. In 2007, 33 hybrids from 3,456 “WT512” seeds and 50 hybrids from 3,457 “CM” seeds were found. The highest frequency of gene flow, 6.19%, was observed in that 2007 trial. These results suggest that a limited isolation distance would be sufficient to prevent gene flow from GM to conventionally bred chili peppers.