摘要：
To understand the mechanism of the color formation of pepper fruit, integrative analysis of the metabolome and transcriptome profiles was performed in pepper varieties with 4 different fruit colors. A total of 188 flavonoids were identified, and most of the anthocyanins, flavonols and flavones showed markedly higher abundances in purple variety than in other varieties, which was linked to the high expression of flavonoid synthesis and regulatory genes. Using weighted gene co-expression network analyses, modules related to flavonoid synthesis and candidate genes that regulate flavonoid synthesis and transport were identified. Furthermore, the analysis of 12 carotenoids showed that the content of xanthophylls at 50days after anthesis was significantly different between the four pepper varieties, which was resulted from the differential expressions of genes downstream of the carotenoid pathway. Our results provide new insights into the understanding of the synthesis and accumulation of flavonoids and carotenoids in pepper fruit.
摘要：
Capsaicinoids are naturally specialized metabolites in pepper and are the main reason that Capsicum fruits have a pungent smell. During the synthesis of capsaicin, MYB transcription factors play key regulatory roles. In particular, R2R3-MYB subfamily genes are the most important members of the MYB family and are critical candidate factors in capsaicinoid biosynthesis. The 108 R2R3-MYB genes in pepper were identified in this study and all are shown to have two highly conserved MYB binding domains. Phylogenetic and structural analyses clustered CaR2R3-MYB genes into seven groups. Interspecies collinearity analysis found that the R2R3-MYB family contains 16 duplicated gene pairs and the highest gene density is on chromosome 00 and 03. The expression levels of CaR2R3-MYB differentially expressed genes (DEGs) and capsaicinoid-biosynthetic genes (CBGs) in fruit development stages were obtained via RNA-seq and quantitative polymerase chain reaction (qRT-PCR). Co-expression analyses reveal that highly expressed CaR2R3-MYB genes are co-expressed with CBGs during early stages of pericarp and placenta development processes. It is speculated that six candidate CaR2R3-MYB genes are involved in regulating the synthesis of capsaicin and dihydrocapsaicin. This study is the first systematic analysis of the CaR2R3-MYB gene family and provided references for studying their molecular functions. At the same time, these results also laid the foundation for further research on the capsaicin characteristics of CaR2R3-MYB genes in pepper.
关键词：
brown planthopper;cross resistance;baseline susceptibility;cycloxaprid
摘要：
The brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is a serious pest of rice. At present, the application of chemical insecticides is the main control option for this pest. BPH has evolved resistance to various classes of insecticides. Cycloxaprid, a new oxabridged cis-configuration neonicotinoid insecticide, is a (nitromethylene) imidazole analog of imidacloprid. This study focused on the baseline susceptibility to cycloxaprid of 18 field samples of N. lugens collected from nine geographical locations in China, as well as possible cross-resistances between cycloxaprid and other important neonicotinoids in one laboratory-selected resistant strain of N. lugens to imidacloprid. The median lethal concentration (LC50) of cycloxaprid for the 18 samples ranged from 1.26 to 14.90 mg/liter. Furthermore, the cross-resistance studies showed that the imidacloprid-resistant strain exhibited a 27.63-fold resistance to imidacloprid and lower levels of cross-resistance to acetamiprid (16.64-fold), thiacloprid (12.64-fold), and nitenpyram (16.90-fold); however, there was no cross-resistance to cycloxaprid (1.92-fold). These results indicate that cycloxaprid could be an effective alternative insecticide for the management of N. lugens, which is urgently needed to prevent or delay further increases in insecticide resistance in N. lugens.
摘要：
Sub-therapeutic antibiotics are widely used as growth promoters in the poultry industry; however, the resulting antibiotic resistance threatens public health. A plant-derived growth promoter, Macleaya cordata extract (MCE), with effective ingredients of benzylisoquinoline alkaloids, is a potential alternative to antibiotic growth promoters. Altered intestinal microbiota play important roles in growth promotion, but the underlying mechanism remains unknown. We generated 1.64 terabases of metagenomic data from 495 chicken intestinal digesta samples and constructed a comprehensive chicken gut microbial gene catalog (9.04 million genes), which is also the first gene catalog of an animal’s gut microbiome that covers all intestinal compartments. Then, we identified the distinctive characteristics and temporal changes in the foregut and hindgut microbiota. Next, we assessed the impact of MCE on chickens and gut microbiota. Chickens fed with MCE had improved growth performance, and major microbial changes were confined to the foregut, with the predominant role of Lactobacillus being enhanced, and the amino acids, vitamins, and secondary bile acids biosynthesis pathways being upregulated, but lacked the accumulation of antibiotic-resistance genes. In comparison, treatment with chlortetracycline similarly enriched some biosynthesis pathways of nutrients in the foregut microbiota, but elicited an increase in antibiotic-producing bacteria and antibiotic-resistance genes. The reference gene catalog of the chicken gut microbiome is an important supplement to animal gut metagenomes. Metagenomic analysis provides insights into the growth-promoting mechanism of MCE, and underscored the importance of utilizing safe and effective growth promoters.
摘要：
Apple Glomerella leaf spot (GLS) is a severe fungal disease that damages apple leaves during the summer in China. Breeding new apple varieties that are resistant to the disease is considered the best way of controlling GLS. Fine mapping and tightly linked marker are critically essential for the preselection of resistant seedlings. In this study, a population of 207 F1 individuals derived from a cross between ‘Golden Delicious’ and ‘Fuji’ was used to construct a fine simple sequence repeat (SSR)-based genetic linkage map. The position of Rgls, a locus responsible for resistance to GLS, was identified on apple linkage group (LG) 15 using SSR markers CH05g05 and CH01d08, which was adapted from a published set of 300 SSR markers that were developed using the bulked segregant analysis (BSA) method. These two SSR markers flanked the gene, and its recombination rate was 8.7% and 23.2%, respectively. A total of 276 newly developed SSR markers around the target region and designed from the genome apple assembly contig of LG15 were screened. Only nine of these were determined to be linked to the Rgls locus. Thus, a total of 11 SSR markers were in linkage with Rgls, and mapped at distances ranging from 0.5 to 33.8 cM. The closest marker to the Rgls locus was S0405127, which showed a genetic distance of approximately 0.5 cM. The first mapping of the gene Rgls was constructed, and the locations of the 11 effective primers in the ‘Golden Delicious’ apple genome sequence were anchored. This result facilitates better understanding of the molecular mechanisms underlying the trait of resistance to GLS and could be used in improving the breeding efficiency of GLS-resistant apple varieties.
摘要：
To investigate whether brassinosteroids (BR) affects cytokinin (CK)-induced anthocyanin biosynthesis, seedlings of the Arabidopsis dwarf4 (dwf4) mutants including partially suppressing coi1 (psc1) and dwf4-102, which are defective in the BR biosynthesis, and the brassinosteroid-insensitive 1-4 (bri1-4) mutant defective in BR signalling were used for the analysis of CK-induced anthocyanin accumulation and the expression of anthocyanin biosynthetic genes and WD-repeat/Myb/bHLH transcription factors. The results show that the CK-induced anthocyanin accumulation was remarkably reduced in dwf4 and bri1-4 mutants, but distinctly increased in the wild type (WT) treated with BR. Moreover, the CK-induced expressions of the late anthocyanin biosynthetic genes including dihydroflavonol reductase, leucoanthocyanidin dioxygenase, and UDP-glucose: flavonoid-3-O-glucosyl transferase were significantly reduced in bri1-4 and dwf4-102 mutants compared to WT. In addition, the expressions of transcription factors production of anthocyanin pigment 1 (PAP1), glabra 3 (GL3), and enhancer of glabra 3 (EGL3) were induced by CK in WT but not in the bri1-4 and dwf4-102 mutants. These results indicate that BR enhanced the CK-induced anthocyanin biosynthesis by up-regulating the late anthocyanin biosynthetic genes and this regulation might be mediated by the transcription factors PAP1, GL3, and EGL3.
摘要：
The hydrophobic nature of most membrane proteins severely complicates their extraction, proteolysis and identification. Although detergents can be used to enhance the solubility of the membrane proteins, it is often difficult for a detergent not only to have a strong ability to extract membrane proteins, but also to be compatible with the subsequent proteolysis and mass spectrometric analysis. In this study, we made evaluation on a novel application of sodium laurate (SL) to the shotgun analysis of membrane proteomes. SL was found not only to lyse the membranes and solubilize membrane proteins as efficiently as SDS, but also to be well compatible with trypsin and chymotrypsin. Furthermore, SL could be efficiently removed by phase transfer method from samples after acidification, thus ensuring not to interfere with the subsequent CapLC-MS/MS analysis of the proteolytic peptides of proteins. When SL was applied to assist the digestion and identification of a standard protein mixture containing bacteriorhodoposin and the proteins in rat liver plasma membrane-enriched fractions, it was found that, compared with other two representative enzyme- and MS-compatible detergents RapiGest SF (RGS) and sodium deoxycholate (SDC), SL exhibited obvious superiority in the identification of membrane proteins particularly those with high hydrophobicity and/or multiple transmembrane domains.
作者机构：
[Wang, Xianchun; Yan, Yizhong; Chen, Ping; He, Quanze; Liu, Yi; Li, Jianjun; Lin, Yong; Liang, Songping] Hunan Normal Univ, Coll Life Sci, Key Lab Prot Chem & Dev Biol, Natl Educ Comm, Changsha 410081, Hunan, Peoples R China.;[Lin, Yong] Hunan Agr Univ, Natl Res Ctr Engn & Technol Utilizat Bot Funct In, Coll Hort & Landscape, Changsha, Hunan, Peoples R China.
通讯机构：
[Wang, Xianchun] H;Hunan Normal Univ, Coll Life Sci, Key Lab Prot Chem & Dev Biol, Natl Educ Comm, Changsha 410081, Hunan, Peoples R China.
关键词：
Membrane proteome;Protein fractionation;Sample cleanup;SDS;Special gradient gel
摘要：
SDS is mostly used to enhance the solubilization and extraction of membrane proteins due to its strong detergency and low cost. Nevertheless, SDS interferes with the subsequent procedures and needs to be removed from the samples. In this work, a special gradient gel electrophoresis (GGE) system was developed to remove SDS from the SDS-solubilized protein samples. As a proof-of-principle experiment, the GGE system was designed to be composed of an agarose loading layer, six polyacrylamide fractionation layers with different concentrations and a high-concentration polyacrylamide sealing layer. The advantages of the GGE system are that it not only can electrophoretically remove SDS efficiently so that the protein loss resulted from the repeated gel washing after electrophoresis was avoided, but also can reduce the complexity of the sample, prevent the precipitation of proteins after loading and avoid the loss of proteins with low molecular weight during the electrophoresis. Using GGE system, about 85% of SDS in the sample and gel was electrophoretically removed and the proteins were fractionated. Compared with the two representative gel-based sample cleanup methods reported in literature, GGE-based strategy significantly improved the identification efficiency of proteins in terms of the number and coverage of the identified proteins.
摘要：
White leaf No.1 is a typical albino tea cultivar grown in China and it has received increased attention in recent years due to the fact that white leaves containing a high level of amino acids, which are very important components affecting the quality of tea drink. According to the color of its leaves, the development of this tea cultivar is divided into three stages: the pre-albinistic stage, the albinistic stage and the regreening stage. To understand the intricate mechanism of periodic albinism, a comparative proteomic approach based on two-dimensional electrophoresis (2-DE) and mass spectrometry was adopted first time to identify proteins that changed in abundance during the three developmental periods. The 2-DE results showed that the expression level of 61 protein spots varied markedly during the three developmental stages. To analyze the functions of the significantly differentially expressed protein spots, 30 spots were excised from gels and analyzed by matrix-assisted laser desorption ionization-time of flight-tandem mass spectrometry. Of these, 26 spots were successfully identified. All identified protein spots were involved in metabolism of carbon, nitrogen and sulfur, photosynthesis, protein processing, stress defense and RNA processing, indicating these physiological processes may play crucial roles in the periodic albinism. Quantitative real-time RT-PCR analysis was used to assess the transcriptional level of differentially expressed proteins. In addition, the ultrastructural studies revealed that the etioplast-chloroplast transition in the leaf cell of White leaf No. 1 was inhibited and the grana in the chloroplast was destroyed at the albinistic stage. In this work, the proteomic analysis revealed that some proteins may have important roles in the molecular events involved in periodic albinism of White leaf No. 1 and identificated many attractive candidates for further investigation. In addition, the ultrastructural studies revealed that the change in leaf color of White leaf No. 1 might be a consequence of suppression of the etioplast-chloroplast transition and damage to grana in the chloroplast induced by temperature. These results provide much useful information to improve our understanding of the mechanism of albinism in the albino tea cultivar.
作者机构：
[Krzysztof Górnik; Renato D. de Castro; Yongqing Liu; Raoul J. Bino; Steven P. C. Groot] Centre for Plant Breeding and Reproduction Research (CPRO-DLO), P.O. Box 16, 6700 AA Wageningen, Netherlands
通讯机构：
[Steven P. C. Groot] C;Centre for Plant Breeding and Reproduction Research (CPRO-DLO), P.O. Box 16, 6700 AA Wageningen, Netherlands
摘要：
<jats:title>Abstract</jats:title><jats:p>Links between germination, DNA replication and β-tubulin accumulation were studied with cabbage (<jats:italic>Brassica oleracea</jats:italic>L.) seeds, by using flow cytometric analysis of nuclear DNA content and immunodetection of β-tubulin levels. The seeds were incubated in water or 0.1–500 mM hydroxyurea solutions. Radicle tips isolated from dry cabbage seeds revealed most 2C (G<jats:sub>o</jats:sub>or G<jats:sub>1</jats:sub>stage) and some 4C (G<jats:sub>2</jats:sub>stage) signals of nuclear DNA contents and a constitutive level of β-tubulin. The onset of DNA replication in the radicle tip was observed between 12 and 24 h of imbibition in water and was preceded by an increase of β-tubulin levels. Incubation of the seeds in 1 mM hydroxyurea retarded DNA replication, whereas an arrest of DNA replication occurred upon incubation in 10 mM hydroxyurea or higher concentrations. The arrest of DNA replication and cell division did not block radicle protrusion and allowed some extension of the radicle. This demonstrated that DNA replication is not a prerequisite for radicle protrusion and initial extension. However, further seedling development, including root growth and root hair development, was dependent on DNA replication. Accumulation of β-tubulin was not affected by hydroxyurea. Thus, it can be deduced that both DNA replication and β-tubulin accumulation are two parallel and independent cell cycle events during seed germination.</jats:p>
摘要：
Using X-ray photography and flow cytometry, the internal morphology and DNA replication activity of wild type (wt), GA- (gib-1) and ABA-deficient (sitw) tomato (Lycopersicon esculentumMill. cv. Moneymaker) mutant seeds were studied. During seed formation, from 30 to 45 d after pollination (DAP) the endosperm becomes solid and the seed starts to gain desiccation tolerance. At this time significant changes occur in the amounts of DNA in radicle tip cells. At 30 DAP, radicle tip cells of the three genotypes manifest about 60% of 2C, 30% of 4C and 10% of 8C amounts of DNA. Upon maturation (45 DAP onwards), most cells in the seeds of the three genotypes arrest in the G1phase of the cell-cycle with 2C amounts of DNA. However, a relatively high proportion of cells with 4C amounts of DNA was detected in the radicle tip cells ofsitwcompared with wild type andgib-1. At the well-matured stage (60 DAP), there were about 2% of seeds with free space in wild type andgib-1, and about 13% insitw. At the over-matured stage (75 DAP), even more seeds with free space were found insitw, whereas no increase in the proportion of the seeds with free space was detected in the other two genotypes. In −1.0 MPa PEG-6000 with or without 10 μMGA4+7, no germination occurred in well-matured wild type andgib-1seeds, whether or not they were dried after harvest. However,sitwseeds were able to germinate both in over-mature fruit and in −1.0 MPa PEG-6000. Priming of dried seeds in −1.0 MPa PEG induced a large amount of free space in almost all seeds of the three genotypes, and nuclear DNA synthesis in the radicle tip cells of wild type andsitwseeds. However, PEG priming of fresh (non-dried) seeds had no effect on the amount of free space and 2C/4C DNA ratios in wild type orgib-1seeds, but did induce free space in about 20–25% ofsitwseeds and provoked 4C signals insitwseeds. Removal of the endosperm and testa opposite the radicle tip of seeds resulted in root protrusion, the induction of free space and an increase of 4C DNA signals in the three genotypes. It is concluded that ABA is crucial for the efficient arrest of tomato embryo radicle tip cells in G1phase upon maturation, whereas GAs play an important role in re-initiating 4C DNA levels upon germination.
摘要：
To explain the differing germination behaviour of seeds of wild type, gibberellin-deficient (gib1) or abscisic acid-deficient (sit(w)) mutants of tomato (Lycopersicon esculentum Mill. cv. Moneymaker), growth and water relations of fruit tissues, seeds and embryos were determined during development. The objective was to determine whether the hormones influenced water relations of fruit and seed tissues and as a consequence germinability. Despite the up to 70% lower fruit weight of the mutants, the fresh and dry seed weights were similar to that of the wild type. Water relations of pericarp and locular tissues in wild type and gib1 fruits were characterized by a slowly increasing Psi(pi) that reached a constant value Psi of -0.60 MPa at 35-40 days after anthesis, resulting in a complete loss of turgor. However, sit(w) fruit tissues maintained their turgor throughout development, mainly as a result of considerably lower Psi(pi) values but similar Psi values compared with the other genotypes. The Psi of wild type and gib1 seeds decreased from -0.50 to -0.80 MPa and Psi(pi) from -0.80 to -1.00 MPa between day 30 and 40. From day 40 onwards, Psi(p) was similar in both genotypes, approximately 0.20 MPa. As in the fruit tissues, sit(w) seed water relations were also characterized by higher turgor values than the other genotypes. Up to day 40, Psi(p) was ca 0.40 MPa, dropped temporarily to zero, and increased again to approximately 0.40 MPa at day 50. Embryo water relations of both mutants deviated from the wild type in that Psi(p) of the gib1 and sit(w) embryos remained at 3.5 MPa and 2.5 MPa, respectively, from day 40 onward, whereas in wild type embryos Psi(p) decreased from 3.0 MPa at day 35 to approximately 1.0 MPa at 50 days after anthesis. This was mainly due to an increasing Psi(pi) which was absent in the mutants. Throughout development there was equilibrium between Psi of pericarp, locular tissues and seeds but between embryo and seed or fruit tissues Psi gradients of up to 1.5 MPa were calculated in the wild type, and up to 1.0 MPa in the mutants. Thus, precocious germination is prevented by the action of the fruit's osmotic environment and ABA on the seed tissues surrounding the embryo and not the embryo itself. Embryos have a Psi which is low enough to overcome the solute potential of the fruit tissues throughout development.
作者机构：
CTR PLANT BREEDING & REPROD RES,DEPT REPROD TECHNOL,6700 AA WAGENINGEN,NETHERLANDS.;HUNAN AGR COLL,DEPT HORT,CHANGSHA 410128,PEOPLES R CHINA.;AGR UNIV WAGENINGEN,DEPT PLANT PHYSIOL,6703 BD WAGENINGEN,NETHERLANDS.;[LIU, YQ] Department of Horticulture, Hunan Agricultural College, Changsha, P.R. China;[BERGERVOET, JHW; DEVOS, CHR; KRAAK, HL; BINO, RJ] Department of Reproduction Technology, Centre for Plant Breeding and Reproduction Research (CPRO-DLO), Wageningen, The Netherlands
通讯机构：
Department of Reproduction Technology, Centre for Plant Breeding and Reproduction Research (CPRO-DLO), POB 16, Netherlands
摘要：
The role of cis-abscisic acid (ABA) and gibberellins (GAs) in the induction of cell-cycle activities has been studied during imbibition and subsequent germination of tomato seeds. Using flow cytometry, nuclear replication activity was investigated in embryo root tips isolated from seeds of the ABA-deficient mutant sit(w), the GA-deficient mutant gib-1, and the wild-type (MM) tomato (Lycopersicon esculentum Mill, cv. Moneymaker) upon imbibition in water, 10 mu M GA(4+7), 5 mu M ABA or 5 mu M ABA + 10 mu M GA(4+7). The nuclei of fully matured dry MM, sit(w) and gib-1 seeds predominantly showed 2C DNA signals, indicating that the cell-cycle activity of most root-tip cells had been arrested at the G(1) phase of nuclear division. However, ABA-deficient sit(w) seeds contained a significantly higher amount of G(2) cells (4C DNA) compared with the other genotypes, suggesting that, during maturation, cell-cycle activity in sit(w) seeds is less efficiently arrested in G(1). Upon imbibition in water, an induction of the 4C signal, indicating nuclear replication, was observed in the root tip cells of both MM and sit(w) embroys. The augmentation in the 4C signal occurred before visible germination. Gib-1 seeds did not show cell-cycle activity and did not germinate in water. Upon imbibition in GA(4+7), both cell-cycle activity and subsequent germination were enhanced in MM and sit(w) seeds, and were induced in gib-1 In ABA, the germination of MM and sit(w) seeds was inhibited while nuclear replication of these seeds was not affected. It is concluded that GA influences germination by acting upon processes that precede cell-cycle activation, while ABA affects growth by acting upon processes that follow cell-cycle activation.
