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In this study, we found that the glucoraphanin (GR) content in broccoli seedlings decreased before first foliage leaf emergence. Methyl jasmonate (MeJA) treatment significantly increased the GR content in broccoli, with effects being consistent over the period of application. Unlike MeJA, abscisic acid (ABA) and salicylic acid (SA) led to slight GR accumulation within 24 h of the application. The feeding of a sulfur-containing compound, MgSO4, via the root of broccoli caused accumulation of GR within 24 h. Thus, both the germination time and the duration of sulfur fertilization and MeJA application are important to maximize GR content in broccoli.

The HEUKCHEEM gene plays an important role in spine color formation. A white spine occurs due to two mutations in HEUKCHEEM and is closely related to the regional distribution of these mutants. Mapping analysis revealed that the HEUKCHEEM gene is co-segregated with the B locus in the regulation of black spine color development in cucumber fruit. HEUKCHEEM induced the expression of the genes involved in the anthocyanin biosynthetic pathway, leading to the accumulation of anthocyanins in black spines. The transiently over-expressed HEUKCHEEM in cucumber and tobacco plants enhanced the expression of anthocyanin biosynthesis-related genes, leading to anthocyanin accumulation. However, two mutations-insertion of the 6994 bp mutator-like transposable element (MULE) sequence into the second intron and one single-nucleotide polymorphism (SNP) of C to T in the second exon of HEUKCHEEM-were identified in white spines, leading to no accumulation of anthocyanin biosynthesis-related gene transcripts and anthocyanins. Furthermore, association analysis using 104 cucumber accessions with different geographical origins revealed that the types of mutations in HEUKCHEEM are strongly linked to geographical origins. The MULE insertion is found extensively in cucumbers with white spines in East Asia and Australia. However, cucumbers with white spines in other areas could be significantly influenced by a single SNP mutation. Our results provide fundamental information on spine color development in cucumber fruits and spine color-based cucumber breeding programs.

The ionizing radiation methods, including X-rays, gamma rays, and neutrons to create variation is well established and used in major crops. Many seed-propagated crops with homozygous parents such as barley, rice, and tomato are resilant to the higher level of damage to chromosomal DNA during mutation induction, followed by repair. In order to improve oil content and other agronomic traits, we treated Camelina sativa Crantz with diverse levels of gamma ray and neutron beam. Overall, 300 Gy of gamma ray and at 50 Gy of neutron beam treated C. sativa showed better agronomic traits. 400 Gy of gamma rays and 200 Gy of fast neutron treatments increased almost four times more oil content than non-treated seeds. In conclusion, our results provide a rapid and economical means to improve agronomic characters of camelina in breeding programs. This is undoubtedly highly valuable, pre-breeding material especially for high oil content.

We investigated the responses of transgenic Arabidopsis plants that express cucumber branched-chain aminotransferases (CsBCATs) under abiotic or biotic stresses. The expression of CsBCAT3 and CsBCAT7 was dramatically increased by various abiotic treatments. The germination of CsBCAT3- or CsBCAT7-expressing Arabidopsis seeds was increased under salt and dehydration treatments, which was correlated with the increased or decreased expression levels of the germination-responsive genes. Although salicylic acid and jasmonic acid increased CsBCAT2 or CsBCAT7 expression, transgenic Arabidopsis plants that express CsBCAT2 or CsBCAT7 did not show the disease resistance to bacteria or fungus. Our results indicate that the CsBCATs affect seed germination of plants under abiotic stresses.

Cucurbitacins are a group of tetracyclic triterpenes produced by members of the Cucurbitaceae family that are known for their bitter taste, and have both positive and negative attributes based on their use. The aim of the present study was to profile cucurbitacins through the quantitative analysis of diverse watermelon (Citrullus spp.) germplasms, including Citrullus colocynthis and Citrullus lanatus, using liquid chromatography–mass spectrometry (LC–MS) and high performance liquid chromatography. We isolated cucurbitacins B and E, and cucurbitacin E glycoside and evaluated the concentration of these compounds in watermelon leaves, fruits, and seedling extracts. High amounts of cucurbitacin E glycosides were found in most of the C. colocynthis leaves at concentrations between 1.3 and 0.9 mg/g of fresh weight, while relatively low concentrations of cucurbitacin B and E were detectable in these tissues. Interestingly, cucurbitacin E glycosides were only detected in most C. colocynthis fruits at concentrations between 0.21 and 3.2 mg/g fresh weight. We also confirmed the correlation between bitter taste and cucurbitacin E glycoside content. Cucurbitacin B and E and cucurbitacin E glycoside were found in most of the cultivars tested, while cucurbitacin agylcones were the primary cucurbitacins identified in seedlings. This study reveals the cucurbitacin composition in various watermelon germplasms and in different plant tissue.

The Mildew resistance locus o (Mlo) is a plant-specific gene family that encodes a protein with seven-transmembrane (TM) domains that play an important role in plant resistance to powdery mildew (PM). PM caused by Podosphaera xanthii is a widespread plant disease and represents the major fungal threat for many Cucurbits. The recently reported Cucurbita maxima genome sequence data provides an opportunity to identify and characterize the MLO gene family in this species. A total of twenty genes designated CmaMLO1 to CmaMLO20 have been identified using an in silico cloning method with the MLO gene sequences of Cucumis sativus, Cucumis melo, Citrullus lanatus, and Cucurbita pepo as probes. These CmaMLOs were evenly distributed on 15 of the 20 C. maxima chromosomes without any obvious clustering. Multiple sequence alignment showed that common structural features of MLO gene family, such as TM domains, a calmodulin-binding domain, and 30 important amino acid residues for MLO function, were well conserved. Phylogenetic analysis of the CmaMLO genes and other plant species revealed seven different clades (I through VII); however, clade IV is specific to monocots (rice, barley and wheat). Expression analysis showed that four of the five CmaMLO genes that belonged to clade V were up-regulated in pumpkins infected with P. xanthii. Phylogenetic and expression analysis provided preliminary evidence that these five genes could be susceptibility genes that are important for PM resistance. This study is the first comprehensive report on MLO genes in C. maxima to our knowledge. These findings will facilitate the functional analysis of MLOs related to PM susceptibility and are valuable resources for the development of disease resistance in pumpkin.

Ethylene is an important regulator of developmental and stress responses in plants, and 1-aminocyclopropane-1-carboxylic acid synthase (ACS) proteins catalyze one of the rate-limiting steps in endogenous ethylene biosynthesis. Accordingly, the function of ACS family genes has been extensively studied in plants including Arabidopsis and tomato; however, little is known about the systemic function of ACS genes in cucumber (Cucumis sativus L.). Here, we investigated the expression patterns of eight cucumber ACS family genes (CsACSs) in a variety of tissues and sex types, as well as in response to exogenous ethylene application, and their ACS activities. Tissue-specific expression profiling in monoecious and gynoecious cucumber plants revealed that some CsACSs were differentially expressed. In particular, the five genes CsACS1, CsACS1-2, CsACS2, CsACS6, and CsACS11 were highly expressed in the shoot apex regions of gynoecious and hermaphroditic cucumber plants. The expression of most CsACSs was also induced by exogenous ethylene application. Furthermore, three CsACS isoforms (CsACS9, CsACS10, and CsACS12) showed no ACS enzymatic activity, which was associated with the amino acid variations in the conserved active residues of CsACS proteins. However, an in vitro pull-down assay revealed that two enzymatically inactive isoforms (CsACS9 and CsACS10) did not significantly interact with four active isoforms (CsACS1, CsACS1-2, CsACS2, and CsACS6). Taken together, our findings will be valuable for elucidating the relationship between RNA expression, ACS activity, protein–protein interactions between CsACSs and cucumber sex types.

Sequencing the complete genome of Camelina sativa will facilitate studies to improve this oilseed crop. We analysed 20 accessions of Camelina spp. using genotyping-by-sequence technology. After stringent screening, 35,783 single nucleotide polymorphisms (SNPs) were generated, and basic genetic studies were performed to check the diversity of these SNPs. STRUCTURE and phylogenetic analyses revealed five subgroups in these 20 Camelina accessions. Winter-types may have diverged from summer-types. Some genomic regions were negatively selected, and most of these were gene-rich regions. As expected, the most ancient subgroup was less affected by negative selection. Marker–trait associations with plant height, leaf length, and pod size generated 154 SNPs, and 72 adjacent genes were significantly associated with these phenotypes. Further large-scale analysis and gene expression studies with these SNPs and genes are needed to develop potentially valuable resources for improving C. sativa.

To develop a molecular method to identify Pseudoperonospora cubensis in cucumber leaves with signs of downy mildew, we compared the nucleotide sequences of ribosomal DNA-internal transcribed spacer, cytochrome oxidase II, and β-tubulin genes of P. cubensis and P. humuli isolates. Seven single nucleotide polymorphisms (SNPs) distinguished P. cubensis and P. humuli based on variations in β-tubulin sequences, and one specific primer set was designed for further analysis. Real-time PCR and high resolution melting analysis showed that the primer set can be used to specifically identify P. cubensis in cucumber leaves with downy mildew.

Global transcriptome analysis revealed common regulons for biotic/abiotic stresses, and some of these regulons encoding signaling components in both stresses were newly identified in this study. In this study, we aimed to identify plant responses to multiple stress conditions and discover the common regulons activated under a variety of stress conditions. Global transcriptome analysis revealed that salicylic acid (SA) may affect the activation of abiotic stress-responsive genes in pepper. Our data indicate that methyl jasmonate (MeJA) and ethylene (ET)-responsive genes were primarily activated by biotic stress, while abscisic acid (ABA)-responsive genes were activated under both types of stresses. We also identified differentially expressed gene (DEG) responses to specific stress conditions. Biotic stress induces more DEGs than those induced by abiotic and hormone applications. The clustering analysis using DEGs indicates that there are common regulons for biotic or abiotic stress conditions. Although SA and MeJA have an antagonistic effect on gene expression levels, SA and MeJA show a largely common regulation as compared to the regulation at the DEG expression level induced by other hormones. We also monitored the expression profiles of DEG encoding signaling components. Twenty-two percent of these were commonly expressed in both stress conditions. The importance of this study is that several genes commonly regulated by both stress conditions may have future applications for creating broadly stress-tolerant pepper plants. This study revealed that there are complex regulons in pepper plant to both biotic and abiotic stress conditions.

A series of (Ti70.5Fe29.5)100−xSnx alloys with x=0, 1, 3, 5, 7 and 9 were fabricated by a suction casting into cylindrical rods with a 3 mm diameter and 50 mm length. Microstructural investigations of these alloys revealed that Sn addition was effective in modulating the phase selection, length-scale of eutectic spacing and morphology of the colony in ultrafine eutectic structures upon solidification. The spherical morphology of the ultrafine eutectic colony was effective in enhancing the plastic strain in the samples. On theother hand, the formation of the bimodal eutectic structure stemming from a large temperature difference between two eutectic temperatures had a strong influence on modulating the phase selection and length-scale of the ultrafine eutectic structures and on controlling the strength and plastic strain of the ultrafine eutectic composites.

To suppress the samarium diffusion from a SmBa2Cu3O7−y (Sm123) seed into an YBa2Cu3O7−y (Y123) compact during a top seeded melt growth (TSMG) process, Y211 buffer disks of various thicknesses (t) were inserted at the seed/compact interface. The effectiveness of the Y211 buffer insert on the suppression of samarium diffusion was estimated from the susceptibility curve and composition analysis for the three top surface regions (region just below the seed/buffer, intermediate region between the buffer and compact edge and compact edge). The difference in the superconducting temperature (Tc) and the superconducting transition width (ΔT) in the three regions was large, when no buffer or thin buffers (t is smaller than 1 mm) were used. As a buffer disk of an appropriate thickness was inserted into the seed/compact interface, the difference in Tc and ΔT in the three regions was much reduced. The composition analysis across the seed/buffer/compact region clearly revealed that the Tc decrease was caused by the samarium diffusion from a seed, which led to the formation of Y1−xSmxBa2Cu3O7−y in the Y123 compact region. The buffer insert technique was demonstrated to insure the uniform superconducting properties of the top surface of TSMG processed Y123 superconductors.

Cytoplasmic male sterility (CMS), one of the most important traits in crop breeding, is used for commercial F(1)-hybrid seed production in peppers (Capsicum annuum L.). A nuclear gene, Restorer-of-fertility (Rf), can induce normal pollen production in CMS plants resulting in fertility. Since the first report of fertility restoration in peppers, various inheritance modes have been suggested, including the presence of a third haplotype of the locus. The pepper Rf gene has not been cloned, and calculated genetic distances of linked markers have varied between research groups. A more precise allelic test and additional genetic mapping are needed to accurately select recombinants for use in marker-assisted backcrossing (MAB). Therefore, the reliability and application of these markers for allelic selection of the Rf gene was tested. Two different F(2) populations, Buja and Tamna, were used for the construction of a linkage map. From these linkage groups, anew closely linked flanking marker of the Rf gene were identified. Previous allelic testing revealed the existence of a third haplotype, Rfls(7701), which can function as dominant (Rf) or recessive (rf). In a previous report, Rfls(7701) was considered to be linked to unstable male sterility (MS). However, our results suggest that unstable MS was induced by a gene residing at another locus rather than by Rfls(7701) haplotype- linked allele.

The anthracnose fungus Colletotrichum gloeosporioides deleteriously affects unripe pepper fruit, but not ripe fruit. Here, we show that the induction of local acquired resistance (LAR) by salicylic acid (SA), 2,6-dichloroisonicotinic acid, or benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester pretreatment protects unripe pepper fruit against the fungus, while jasmonic acid (JA) does not. The SA-mediated LAR in the unripe fruit inhibited the fungal appressoria, resulting in protection against fungal infection. Microarray analysis revealed that 177 of 7,900 cDNA clones showed more than fourfold transcriptional accumulation in SA-treated unripe fruit. The reverse transcription-polymerase chain reaction showed that most of the SA-responsive genes (SRGs) were regulated by SA, but not by JA or ethylene-releasing ethephon. Furthermore, most of the SRGs were preferentially expressed in the ripe fruit. These results suggest that the SA-mediated transcriptional regulation of SRGs has a critical role in the resistance of ripe pepper fruit to fungal infection.

A series of microarray analyses employing the expressed sequence tags (ESTs) of hot pepper was conducted in an effort to elucidate the molecular mechanisms inherent to hypersensitive response (HR) by viral or bacterial pathogens. There were 2535 ESTs exhibiting differential expression (over 2-fold changes) among about 5000 ESTs during viral or bacterial response. Further, via virus-induced gene silencing (VIGS) and TMV-infection studies, we were able to isolate several ESTs, which may be relevant to defense response against TMV. Of these ESTs, Capsicum annuum fatty acid desaturase 1 (CaFAD1) showed the distinct phenotype against TMV infection and thus was subjected to further study. CaFAD1-silenced plants showed weaker resistance against TMV-P0 infection compared to TRV2 control plants. Also the suppression of FAD1 expression caused blocking of cell death induced by Bcl2-associated X (Bax) protein in tobacco plants. Therefore, this report presents that both microarray and VIGS approaches are feasible in hot pepper plants and the TMV-induced CaFAD1 plays a role in HR response.

The CCR4-associated factor 1 (CAF1) protein belongs to the CCR4-NOT complex, which is an evolutionary conserved protein complex and plays an important role in the control of transcription and mRNA decay in yeast and mammals. To investigate the function of CAF1 in plants, we performed gain- and loss-of-function studies by overexpression of the pepper CAF1 (CaCAF1) in tomato and virus-induced gene silencing (VIGS) of the gene in pepper plants. Overexpression of CaCAF1 in tomato resulted in significant growth enhancement, with increasing leaf thickness, and enlarged cell size by more than twofold when compared with the control plants. A transmission electron microscopic analysis revealed that the CaCAF1-transgenic tomato plants had thicker cell walls and cuticle layers than the control plants. In addition to developmental changes, overexpression of CaCAF1 in tomato plants resulted in enhanced resistance against the oomycete pathogen Phytophthora infestans. Additionally, microarray, northern and real-time polymerase chain reaction analyses of CaCAF1-transgenic tomato plants revealed that multiple genes were constitutively upregulated, including genes involved in polyamine biosynthesis, defence reactions and cell-wall organogenesis. In contrast, VIGS of CaCAF1 in pepper plants caused significant growth retardation and enhanced susceptibility to the pepper bacterial spot pathogen Xanthomonas axonopodis pv. vesicatoria. Our results suggest roles for plant CAF1 in normal growth and development, as well as in defence against pathogens.

We previously isolated CaPIF1 (Capsicum annuum Pathogenesis Induced Factor) from pepper leaves following their infection with the soybean pustule pathogen Xanthomonas axonopodis pv. glycines 8ra. The CaPIF1 gene encodes a plant-specific Cys-2/His-2 zinc finger protein that functions as a transcription factor. To elucidate the role of the CaPIF1 transcription factor in gene regulation, we transformed tomato plants expressing full-length CaPIF1 and conducted microarray experiments. The ectopic overexpression of pepper CaPIF1 in tomato resulted in a massive change in gene expression: of a total of 8700 genes on the microarray, 110 were up- or downregulated, without exhibiting any visual morphological abnormality. The microarray analysis showed that CaPIF1 turned on genes involved in metabolic pathways, and stress and defense responses; the results also suggested that the upregulation of the genes might increase tolerance to cold stress and pathogen attack. The transgenic tomato displayed more tolerance to cold stress and to the bacterial pathogen Pseudomonas syringae pv. tomato DC 3000, and the tolerance levels were correlated with CaPIF1 expression levels. These results suggest that CaPIF1 is a unique Cys-2/His-2 transcription factor, regulating multiple genes both directly and indirectly, and thus conferring increased tolerance to biotic and abiotic stresses.

As genome and cDNA sequencing projects progress, a tremendous amount of sequence information is becoming publicly available. These sequence resources can be exploited for gene discovery and marker development. Simple sequence repeat (SSR) markers are among the most useful because of their great variability, abundance, and ease of analysis. By in silico analysis of 10,232 non-redundant expressed sequence tags (ESTs) in pepper as a source of SSR markers, 1,201 SSRs were found, corresponding to one SSR in every 3.8 kb of the ESTs. Eighteen percent of the SSR-ESTs were dinucleotide repeats, 66.0% were trinucleotide, 7.7% tetranucleotide, and 8.2% pentanucleotide; AAG (14%) and AG (12.4%) motifs were the most abundant repeat types. Based on the flanking sequences of these 1,201 SSRs, 812 primer pairs that satisfied melting temperature conditions and PCR product sizes were designed. 513 SSRs (63.1%) were successfully amplified and 150 of them (29.2%) showed polymorphism between Capsicum annuum 'TF68' and C. chinense 'Habanero'. Dinucleotide SSRs and EST-SSR markers containing AC-motifs were the most polymorphic. Polymorphism increased with repeat length and repeat number. The polymorphic EST-SSRs were mapped onto the previously generated pepper linkage map, using 107 F(2) individuals from an interspecific cross of TF68 x Habanero. One-hundred and thirtynine EST-SSRs were located on the linkage map in addition to 41 previous SSRs and 63 RFLP markers, forming 14 linkage groups (LGs) and spanning 2,201.5 cM. The EST-SSR markers were distributed over all the LGs. This SSR-based map will be useful as a reference map in Capsicum and should facilitate the use of molecular markers in pepper breeding.

Electrical and superconducting properties of BiSrCaCuO superconductor prepared by partial melting method were determined to study its superconducting mechanism. Induced voltage of the BiSrCaCuO superconductor was not so significantly dependent upon on the shape and size of the superconductor. Anti-magnetism was less dependent upon the melting and the annealing temperatures. BiSrCaCuO film prepared at 1158 K shows the maximum magnetic susceptibility in this study. Differential conductance behavior of the superconductor with magnetic flux was not well matched by a conventional flux flow model. It suggests that a superconducting mechanism for type II superconductor should be able to explain the fact that magnetic properties arise from the interaction between the trapped magnetic flux and weak link of the superconducting connectors forms in the superconducting material.

The tomato (Lycopersicon esculentum) high-pigment (hp) locus was originally described as having enhanced fruit-quality characteristics and has also been shown to regulate responses to light during growth and development. Specifically, the hp phenotype suggests that the normal HP gene-product serves as a negative regulator of light signal-transduction, as has been proposed for many of the previously described Arabidopsis thaliana photomorphogenic mutants. Consequently, hp represents a tool for both genetic dissection of light signal-transduction and manipulation of fruit quality in tomato. As a first step toward isolation of the HP gene, the hp locus was mapped to tomato chromosome 2, adjacent to the 45s rDNA locus, using DNA markers and an interspecific cross of L. esculentum×L. cheesmannii. We have simultaneously identified DNA markers which may be useful for gene isolation and marker-assisted selection. We have additionally extended characterization of the hp phenotype to demonstrate increased sucrose and flavonoid accumulation in ripe hp/hp fruit. Analysis of plastid DNA copy number relative to genomic DNA content indicates that the hp locus regulates plastome DNA concentration, and possibly plastid number, in response to light.

The CCR4-associated factor 1 (CAF1) protein belongs to the CCR4-NOT complex, which is an evolutionary conserved protein complex and plays an important role in the control of transcription and mRNA decay in yeast and mammals. To investigate the function of CAF1 in plants, we performed gain- and loss-of-function studies by overexpression of the pepper CAF1 (CaCAF1) in tomato and virus-induced gene silencing (VIGS) of the gene in pepper plants. Overexpression of CaCAF1 in tomato resulted in significant growth enhancement, with increasing leaf thickness, and enlarged cell size by more than twofold when compared with the control plants. A transmission electron microscopic analysis revealed that the CaCAF1-transgenic tomato plants had thicker cell walls and cuticle layers than the control plants. In addition to developmental changes, overexpression of CaCAF1 in tomato plants resulted in enhanced resistance against the oomycete pathogen Phytophthora infestans. Additionally, microarray, northern and real-time polymerase chain reaction analyses of CaCAF1-transgenic tomato plants revealed that multiple genes were constitutively upregulated, including genes involved in polyamine biosynthesis, defence reactions and cell-wall organogenesis. In contrast, VIGS of CaCAF1 in pepper plants caused significant growth retardation and enhanced susceptibility to the pepper bacterial spot pathogen Xanthomonas axonopodis pv. vesicatoria. Our results suggest roles for plant CAF1 in normal growth and development, as well as in defence against pathogens.