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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.

To date studies revealed that MYB28 intensively involved biosynthesis of GSLs, there is no direct evidence of MYB28 in glucoraphanin (GR) biosynthesis of broccoli. Furthermore, Agrobacterium (Agro)-infiltration also induced GSLs in Arabidopsis. However, there is no information regarding Agro-dependent GR accumulation in broccoli. We revealed that over-expression of BroMYB28 could accumulate GR, and Agro-infiltration is also enough to induce the accumulation of GR in broccoli. From our results, it is suggested that they used different regulatory mechanisms; BroMYB28 over-expression induced both BroMYB28 and BroMYB29 (Bol008849-like) transcripts; Agro-infiltration induced only BroMYB29 (Bol008849-like) transcripts.

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.

Various cucurbitacins have been isolated, and their structures have been elucidated. Owing to their economic potential and importance as active pharmacological compounds, their cytotoxicity in various cancer cells has been assessed. Here, we mined several candidate genes with potential involvement in cucurbitacin biosynthesis in watermelon (Citrullus lanatus) and performed in vitro enzymatic assays and instrumental analyses using various substrates to identify cucurbitacin functions and products. Enzymatic activities of two acetyltransferases (ACTs) and one UDP-glucosyltransferase (UGT) against cucurbitacins were confirmed, resulting in the synthesis of novel cucurbitacins in vivo and/or in vitro to our knowledge. As ACTs and UGT are involved in the dynamic conversion of cucurbitacins by catalyzing acetylation and glucosylation at moieties in the cucurbitacins skeleton, these findings improve our knowledge on how these genes contribute to the diversity of cucurbitacins., Kim et al. use RNAseq of two watermelons to select candidate genes coding for enzymes that catalyze modifications of cucurbitacins. They characterise four of the 16 candidate enzymes (3 different acetyltransferases and one UDP-glucosyltransferase) by HPLC, LC-MS, NMR, and in vitro enzymatic assay. They further show with in vivo assay in Drosophila, that acetylation of cucurbitacin increases neuronal activity in insects.

QTL mapping and RT-PCR analyses identified the CsGy5G015660 as a strong powdery mildew resistance candidate gene and natural variation of CsGy5G015660 allele was observed using 115 core germplasm. Powdery mildew (PM) is among the most serious fungal diseases encountered in the cultivation of cucurbits. The development of PM-resistant inbred lines is thus of considerable significance for cucumber breeding programs. In this study, we applied bulked segregant analysis combined with QTL-seq to identify PM resistance loci using F2 population derived from a cross between two Korean cucumber inbred lines, PM-R (resistant) and PM-S (susceptible). Genome-wide SNP profiling using bulks of the two extreme phenotypes identified two QTLs on chromosomes 5 and 6, designated pm5.2 and pm6.1, respectively. The two PM resistance loci were validated using molecular marker-based classical QTL analysis: pm5.2 (30% R2 at LOD 11) and pm6.1 (11% R2 at LOD 3.2). Furthermore, reverse transcriptase-PCR analyses, using genes found to be polymorphic between PM-R and PM-S, were conducted to identify the candidate gene(s) responsible for PM resistance. We found that transcripts of the gene CsGy5G015660, encoding a putative leucine-rich repeat receptor-like serine/threonine-protein kinase (RPK2), showed specific accumulation in PM-R prior to the appearance of disease symptoms, and was accordingly considered a strong candidate gene for PM resistance. In addition, cleaved amplified polymorphic sequence markers from CsGy5G015660 were developed and used to screen 35 inbred lines. Natural variation in the CsGy5G015660 allele was also observed based on analysis of a core collection of 115 cucumber accessions. Our results provide new genetic insights for gaining a better understanding of the genetic basis of PM resistance in cucumber, and pave the way for further utilization in cucumber PM resistance breeding programs.

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.

Two genes, CsLRR-RPK2 (CsGy5G015660) and CsaMLO8 (Csa5G623470), have been considered as powdery mildew (PM) resistance genes in cucumbers. In this study, we evaluated the involvement of the alleles of these two genes in PM resistance in 100 commercial Korean cucumber inbred lines. To achieve this, we developed cleaved amplified polymorphic sequences (CAPS) and InDel markers from CsLRR-RPK2 and CsaMLO8. Genotyping analysis indicated that the CsLRR-RPK2-CAPS marker showed a stronger correlation with the PM-resistant phenotype, with an 84% consistency compared to the CsaMLO8-InDel marker. The use of the CsaMLO8-InDel marker showed a 70% consistency between phenotype and genotype results. It was proposed that the CsLRR-RPK2-CAPS marker successfully eliminated PM-susceptible inbred lines, since both genotype and phenotype results were 100% identical. Furthermore, the present study revealed that the introduction of one of these alleles is probably enough to confer PM resistance in cucumbers. However, seven PM-resistant inbred lines harbored either CsaMLO8 or CsLRR-RPK2 alleles, indicating that there is another PM-resistant resource(s) besides CsaMLO8- and CsLRR-RPK2–originated resistance in the commercial Korean inbred lines. Our results provide reliable evidence confirming two PM-resistant candidate genes for the detection of PM resistance resources in cucumber inbred lines.

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.

This study is aimed to investigate the occurrence of Phyllocnistis citrella Stainton (citrus leafminer; CLM), which has recently caused increasing damage to citrus farms in southern South Korea, and its natural enemies, which can act as biological control agents. In the present study, CLM monitoring using sex pheromone traps were conducted in the major citrus farms in the Jeju region in South Korea. Also a survey of parasites was carried out to detect the effective control agent for CLM. During the investigation from 2011 to 2015, a relatively large number of adult CLM (2,386,990) were observed in the sex pheromone traps. The mean annual occurrence of CLM was 477,398, which showed an increasing trend with the increase in temperature. A survey of parasites was conducted in November 2015. Six parasites were found, of which, Quadrastichus sp. and Sympiesis sp. showed the highest rates of parasitism. The mean rate of parasitism during the survey period was 3.97 %. We discovered four new species of parasites of CLM in South Korea.

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.

The overexpression of CsBCATs promotes flowering in Arabidopsis by regulating the expression of flowering time genes. The branched-chain amino acid transferases (BCATs) play an important role in the metabolism of branched-chain amino acids (BCAAs), such as isoleucine, leucine, and valine. They function in both the synthesis and the degradation of this class of amino acids. We identified and characterized the three BCAT genes in cucumber (Cucumis sativus L.). The tissue-specific expression profiling in cucumber plants revealed that CsBCAT2 and CsBCAT7 were highly expressed in the reproductive tissues, whereas CsBCAT3 expression was highly detected in the vegetative tissues. The subcellular localization patterns of three CsBCATs were observed in the mitochondria. The functional analyses of CsBCATs showed that CsBCAT2 and CsBCAT3 restored the growth of bat1Δ/bat2Δ double knockout yeast (Saccharomyces cerevisiae), and CsBCAT3 and CsBCAT7 with different substrate preferences acted in a reverse reaction. The transgenic approach demonstrated that the overexpression of the three CsBCATs resulted in early flowering phenotypes, which were associated with the upregulation of FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) in a manner in which they were dependent on GIGANTEA (GI)/CONSTANS (CO) and SHORT VEGETATIVE PHASE (SVP)/FLOWERING LOCUS C (FLC) modules. Our results, which are observed in conjunction, suggest that there is an interconnection between BCAT genes that function in BCAA metabolism and the flowering time in plants.

The objective of this study was comparison of seed yields according to different seeding rates, seeding time and application of chemical fertilizations in Yanji region of China. The experiment was conducted on commercial farmland at Yanji region in 2013. All the experimental fields were designed following randomized block design with 3 replicates. The plant spacing was applied as distance. To check the effect of seeding rate, two different seeding rate, 0.2 kg/0.1ha and 0.5 kg/0.1ha were applied. The higher seed yield was observed in low seeding rate (0.2 kg/0.1ha). The application of fertilizer (mixture of N and P) showed different results following different experimental fields. However, there were little positive effects following fertilizer application into commercial farmland. When we compare seed yields between two different seeding dates, May and May, the earlier seeding date ( May) showed higher seed yields. In considering these results, low seeding rate and early seeding time is important for getting high camelina seed yields.

카멜리나(Camelina sativa)는 십자화과(Brassicaceae)에 속하는 유지작물이다. 카멜리나 종자에는 건물 중의 약 40%에 해당하는 저장 오일을 가지고 있고, 이러한 저장오일은 식품뿐만 아니라 산업재료로 이용이 가능하다. Microsomal delta-12 fatty acid desaturase2 (FAD2) 효소는 oleic acid를 linoleic acid로 전환시키는데, 종자 내 oleic acid의 함량 차이를 보이는 품종들에서 FAD2 유전자의 polymorphism이 보고되었다. 본 연구에서는 카멜리나(Camelina sativa L. 품종 CAME)에 존재하는 3개의 FAD2 유전자를 발달하는 종자로부터 분리하였다. 3개의 카멜리나 FAD2 유전자의 염기서열 및 아미노산 서열은 카멜리나 품종 Sunesone과 SRS933으로부터 확인된 FAD2 유전자들과 여러 단자엽 및 쌍자엽 식물의 FAD2 유전자들의 염기서열 및 아미노산 서열과 상동성을 비교하였다. FAD2 효소의 활성을 결정짓는다고 알려진 histidine motif (HECGHH, HRRHH 그리고 HVAHH)와 효소 활성에 영향을 주는 SNP (single nucleotide polymorphism) 마커라고 알려진 소수성 아미노산 계열인 valine 혹은 isoleucine이 3 개의 카멜리나 FAD2에서도 잘 보존되어 있음을 확인하였다. 세개의 카멜리나 FAD2 유전자들 중 CsFAD2-1의 경우 카멜리나의 발달하는 조직에서 전반적으로 높은 발현 양상을 보이는 반면 CsFAD2-2와 CsFAD2-3.1은 꽃과 발달하는 종자에서 특이적인 발현을 보였다. 애기장대 fad2-2 돌연변이체에 3개의 카멜리나 FAD2를 각각 도입한 형질전환 식물체의 종자에는 애기장대 fad2-2 돌연변이체 종자대비 oleic acid의 함량이 감소하고, linoleic acid 함량은 증가하는 표현형이 관찰되었다. 이러한 결과는 카멜리나로부터 분리된 3개의 FAD2가 효소로서 활성을 가지고 있다는 것을 의미한다. 더불어 분리된 카멜리나의 FAD2 유전자는 종자 오일 성분이 변화된 유지작물을 개발하는데 응용될 수 있을 것이다.

Until now, only one species, Phyllocnistis citrella Stainton, of the genus Phyllocnistis belonging to the family Gracillariidae is listed in Korea, without available information on its identification and morphology, which is now a very serious and important insect pest species in southern area. This study was carried out to provide the illustration with genital structure and DNA barcode data for rapid monitoring, which has not been presented in this country to date.

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.

QTL mapping using NGS-assisted BSA was successfully applied to an F 2 population for downy mildew resistance in cucumber. QTLs detected by NGS-assisted BSA were confirmed by conventional QTL analysis. Downy mildew (DM), caused by Pseudoperonospora cubensis, is one of the most destructive foliar diseases in cucumber. QTL mapping is a fundamental approach for understanding the genetic inheritance of DM resistance in cucumber. Recently, many studies have reported that a combination of bulked segregant analysis (BSA) and next-generation sequencing (NGS) can be a rapid and cost-effective way of mapping QTLs. In this study, we applied NGS-assisted BSA to QTL mapping of DM resistance in cucumber and confirmed the results by conventional QTL analysis. By sequencing two DNA pools each consisting of ten individuals showing high resistance and susceptibility to DM from a F2 population, we identified single nucleotide polymorphisms (SNPs) between the two pools. We employed a statistical method for QTL mapping based on these SNPs. Five QTLs, dm2.2, dm4.1, dm5.1, dm5.2, and dm6.1, were detected and dm2.2 showed the largest effect on DM resistance. Conventional QTL analysis using the F2 confirmed dm2.2 (R 2 = 10.8–24 %) and dm5.2 (R 2 = 14–27.2 %) as major QTLs and dm4.1 (R 2 = 8 %) as two minor QTLs, but could not detect dm5.1 and dm6.1. A new QTL on chromosome 2, dm2.1 (R 2 = 28.2 %) was detected by the conventional QTL method using an F3 population. This study demonstrated the effectiveness of NGS-assisted BSA for mapping QTLs conferring DM resistance in cucumber and revealed the unique genetic inheritance of DM resistance in this population through two distinct major QTLs on chromosome 2 that mainly harbor DM resistance.

Flowering time in members of the Solanaceae plant family, such as pepper (Capsicum spp.) and tomato (Solanum lycopersicum), is an important agronomic trait for controlling shoot architecture and improving yield. To investigate the feasibility of flowering time regulation in tomato, an RNA-binding protein (RBP) encoding gene homologous to human Nucleolar protein interacting with the forkhead-associated (FHA) domain of pKI-67 (NIFK), CaRBP, was isolated from hot pepper. The function of CaRBP was determined in transgenic tomato. The deduced amino acid sequence includes an RNA recognition motif (RRM) and showed most similarity to the RRM present in a putative RBP encoded by human NIFK. CaRBP was highly expressed in the vegetative and reproductive tissues, such as leaves and fruits, respectively. Subcellular localization analysis indicated that CaRBP is a nucleolar protein. Heterologous expression of CaRBP under 35S promoter in tomato plants induced severe alteration of flowering with additional defects of vegetative organs. This floral retardation was associated with the alteration of SFT/SP3D and SlSOC1s as floral integrators. Furthermore, CaRBP reduces the expression levels of SlCOLs/TCOLs via changes in the expression of SlCDF3, SlFBHs, and SlFKF1s. This indicates a repressive effect of CaRBP on the regulation of flowering time in tomato. Overall, these results suggest that alteration in CaRBP expression levels may provide an effective means of controlling flowering time in day-neutral Solanaceae.

The relationships of sterase- and lipase-like proteins with three signaling molecules (salicylic acid, jasmonic acid, and ethylene) expressed during plant–pathogen interactions were studied. We isolated two carboxylesterase (AtCXE) genes, AtCXE8 and AtCXE9, from Arabidopsis thaliana. The AtCXE8 and AtCXE9 proteins possess carboxylesterase motifs (-GXSXG-) and catalytic triads (Ser, Asp, and His). We demonstrated that recombinant AtCXE8 and AtCXE9 proteins have both enzymatic activity and specific activity for p-nitrophenyl butyrate (C4) in vitro. Moreover, the enzymatic activity of recombinant AtCXE8 was twofold higher than that of AtCXE9. To gain a better understanding of the endogenous role of the AtCXE8 gene in Arabidopsis, we identified an enhancer trap T-DNA mutant (AtCXE8_KO) and used it to show that the AtCXE8 gene was induced in response to fungal infection. AtCXE8_KO plants were also more susceptible to infections than wild-type Col-0 plants. Moreover, overexpression of the AtCXE8 gene in transgenic Arabidopsis plants led to enhanced disease resistance against B. cinerea. Taken together, our data indicate that AtCXE8 plays a role in promoting resistance to fungal invasion.

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.

In this study, we searched for anther-specific genes involved in male gametophyte development in apple (Malus x domestica Borkh. cv. Fuji) by differential display-PCR. Three full-length cDNAs were isolated, and the corresponding genomic sequences were determined by genome walking. The identified genes showed intronless 228- to 264-bp open reading frames and shared 82-90% nucleotide sequence. Sequence analysis identified that they encoded a putative arabinogalactan protein (AGP) and were designated MdAGP1, MdAGP2, and MdAGP3, respectively. RT (reverse transcriptase)-PCR revealed that the MdAGP genes were selectively expressed in the stamen. Promoter analysis confirmed that the MdAGP3 promoter was capable of directing anther- or pollen-specific expression of the GUS reporter in tobacco and apple. Furthermore, expression of ribosome-inactivating protein under the control of the MdAGP3 promoter induced complete sporophytic male sterility as we had expected.

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.

The effect of BaCeO 3 addition (0-45 wt%) on the microstructure and critical current density ot melt-processed, Y 2 BaCuO 5 (Y211) excessive Y 1.5 Ba 2 Cu 3 O x (Y1.5) superconductors was investigated. The BaCeO 3 powder was synthesized by the conventional powder calcination method involving powder weighing, mixing and repeated firing process. The prepared BaCeO 3 powders with various compositions were mixed with Y 1.5 Ba 2 Cu 3 O x powder, made compacts and finally melt-processed with top seeding. It was found that the size of Y211 particles inside YBa 2 Cu 3 O 7-y (Y123) was linearly reduced as the amount of BaCeO 3 increased. In addition, fine BaCeO 3 particles are distributed with Y211 particles in Y123 matrix, but were agglomerated at much BaCeO 3 addition of 45 wt%. The current density (J c ) increased as a weight fraction of BaCeO 3 increased and it reached to maximum at 35 wt% BaCeO 3 . The J c variation by BaCeO 3 addition was explained in terms of the BaCeO 3 and Y211 distribution in a Y123 matrix.

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.

Unique developmental aspects, divergent phenotypes and habitats of Solanaceae make the family an ideal model to investigate the basis of diversification and adaptation. In view of this uniqueness, a global tomato genome sequencing project designated "International Solanaceae Genome Project (SOL): Systems Approach to Diversity and Adaptation" has been launched. The goal of this initiative is to sequence the 220 Mb euchromatin that is expected to contain the majority of coding sequences, rather than 950 Mb full-length tomato genome. Given the high degree of similarity of tomato and pepper genomes, it will be particularly interesting to apply tomato genome information to pepper using a comparative genomics approach. In this review, we discuss the current progress in sequencing of tomato in Korea, genomics resources of pepper and beneficiary of the tomato sequence.

Cucumber is a typical monoecious having separate male and female flowers on the same plant, and sex expression in cucumber is mainly determined by three major genes: F/f, M/m and A/a. Gynoecy plays an important role in cucumber hybrid breeding, and the use of gynoecious lines as maternal parents ensures high productivity. This study aimed to identify a co-dominant marker linked to Female (F) locus to distinguish homozygous and heterozygous gynoecious lines for efficient selection of gynoecy in cucumber breeding. Firstly, we analyzed a 50-kb genomic sequence of five gynoecious and five monoecious inbred lines to detect the polymorphism linked to F locus. A pair of specific primers, Cs-BCAT-F/Cs-BCAT-R, based on an In/Del polymorphism at 3′-UTR of branched-chain amino acid transaminase (BCAT) gene was designed to examine the polymorphism in gynoecious and monoecious parents, their F 1 hybrids and two F 2 segregating populations. The PCR fragments amplified with Cs-BCAT-F/Cs-BCAT-R co-segregated with sexual phenotypes in the F 2 populations, behaving as a co-dominant marker with two alleles: F (gynoecious) and f (monoecious). When we further verified the consistency of the co-dominant marker using additional 55 diverse inbred lines, it can explain ~90 % of accessions. Linkage analysis also showed that the gene which enhances the number of female flowers co-segregated with the co-dominant marker on the long arm of chromosome 6. This is the first report for the development of F locus-specific co-dominant marker which can distinguish perfectly homozygous and heterozygous gynoecious, and it could be used in marker-assisted selection in cucumber breeding.

The human genome project, which ended in 2003, provided a human genome map with 99.99 % accuracy. This project stimulated association studies between traits and genes and allowed the discovery of new genes. In 2006, an innovational method known as genome-wide association study (GWAS) was developed. GWAS is different from the traditional method of studying associations between a few candidate genes and traits in that GWAS can handle about one million single-nucleotide polymorphisms (SNPs) simultaneously.

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.

Two linkage maps of pepper were constructed and used to identify quantitative trait loci (QTLs) conferring resistance to Phytophthora capsici. Inoculations were done with 7 isolates: 3 from Taiwan, 3 from California, and 1 from New Mexico. The first map was constructed from a set of recombinant inbred lines (RILs) of the PSP-11 (susceptible) × PI201234 (resistant) cross; and the second map was from a set of F2lines of the Joe E. Parker' (susceptible) × 'Criollo de Morelos 334' (resistant) cross. The RIL map covered 1466.1 cM of the pepper genome, and it consisted of 144 markers - 91 amplified fragment length polymorphisms (AFLPs), 34 random amplified polymorphic DNA (RAPDs), 15 simple sequence repeats (SSRs), 1 sequence characterized amplified region (SCAR), and 3 morphological markers - distributed over 17 linkage groups. The morphological markers mapped on this population were erect fruit habit (up), elongated fruit shape (fse), and fasciculate fruit clusters (fa). The F2map consisted of 113 markers (51 AFLPs, 45 RAPDs, 14 SSRs, and 3 SCARs) distributed in 16 linkage groups, covering a total of 1089.2 cM of the pepper genome. Resistance to both root rot and foliar blight were evaluated in the RIL population using the 3 Taiwan isolates; the remaining isolates were used for the root-rot test only. Sixteen chromosomal regions of the RIL map contained single QTLs or clusters of resistance QTLs that had an effect on root rot and (or) foliar blight, revealing a complex set of genetics involved in resistance to P. capsici. Five QTLs were detected in the F2map that had an effect on resistance to root rot.Key words: Phytophthora capsici, QTLs, fasciculate, resistance, isolates, pepper, fruit shape.

An ERF/AP2-type transcription factor (CaPF1) was isolated by differential-display reverse transcription-PCR, following inoculation of the soybean pustule pathogen Xanthomonas axonopodis pv glycines 8ra, which induces hypersensitive response in pepper (Capsicum annuum) leaves. CaPF1 mRNA was induced under conditions of biotic and abiotic stress. Higher levels of CaPF1 transcripts were observed in disease-resistant tissue compared with susceptible tissue. CaPF1 expression was additionally induced using various treatment regimes, including ethephon, methyl jasmonate, and cold stress. To determine the role of CaPF1 in plants, transgenic Arabidopsis and tobacco (Nicotiana tabacum) plants expressing higher levels of CaPF1 were generated. Gene expression analyses of transgenic Arabidopsis and tobacco revealed that the CaPF1 level in transgenic plants affects expression of genes that contain either a GCC or a CRT/DRE box in their promoter regions. Furthermore, transgenic Arabidopsis plants expressing CaPF1 displayed tolerance against freezing temperatures and enhanced resistance to Pseudomonas syringae pv tomato DC3000. Disease tolerance was additionally observed in CaPF1 transgenic tobacco plants. The results collectively indicate that CaPF1 is an ERF/AP2 transcription factor in hot pepper plants that may play dual roles in response to biotic and abiotic stress in plants.

From a pathogen-inoculated hot pepper (Capsicum annuum L. cv. Pukang) leaf EST, we identified a cDNA clone, pCaERFLP1, encoding a putative transcription factor that contains a single ERF/AP2 DNA binding domain. CaERFLP1 was most closely related to tomato LeERF2 (73%), both of which belong to the novel ERF class IV typified by the N-terminal MCGGAIL signature sequence, while it had a limited sequence identity (25-30%) with Arabidopsis AtERFs and tobacco NtERFs. Quantitative gel retardation assays revealed that bacterially expressed full-length CaERFLP1 was able to form a specific complex with both the GCC box and DRE/CRT motif, with its binding affinity for GCC being stronger than for DRE/CRT. When fused to the GAL4 DNA binding domain, the N-terminal CaERFLP1(1-37) and C-terminal CaERFLP1(198-264) mutant polypeptides could function individually as transactivators in yeast. This suggests that two separate domains of CaERFLP1 may play distinct roles in transcription activation. In particle co-bombardment experiments, CaERFLP1 activated the transcription of reporter genes containing the 4X[GCC] element in tobacco cells. In hot pepper plants, the steady-state level of CaERFLP1 mRNA was markedly induced by multiple environmental factors, such as pathogen infection, ethylene, mechanical wounding and high salinity. Furthermore, ectopic expression of CaERFLP1 in transgenic tobacco plants resulted in partially improved tolerance against the bacterial pathogen Pseudomonas syringae and salt stress (100 mM NaCl). Consistently, various defense-related genes, including GCC box-containing PR genes and the DRE/CRT-containing LTI45 (ERD10) gene, were constitutively expressed in 35S::CaERFLP1 tobacco plants. Thus, it appears that CaERFLP1 is functional in tobacco cells, where it induces the transactivation of some GCC- and DRE/CRT-genes to trigger a subset of stress response. Here, the possible biological role(s) of CaERFLP1 is discussed, especially with regard to the possibility that CaERFLP1 has multiple functions in the regulation of GCC- and DRE/CRT-mediated gene expression in hot pepper plants.

Host resistance is usually parasite-specific and is restricted to a particular pathogen races, and commonly is expressed against specific pathogen genotypes. In contrast, resistance shown by an entire plant species to a species of pathogen is known as non-host resistance. Therefore, non-host resistance is the more common and broad form of disease resistance exhibited by plants. As a first step to understand the mechanism of non-host plant defense, expressed sequence tags (EST) were generated from a hot pepper leaf cDNA library constructed from combined leaves collected at different time points after inoculation with non-host soybean pustule pathogen (Xanthomonas axonopodis pv. Glycines; Xag). To increase gene diversity, ESTs were also generated from cDNA libraries constructed from anthers and flower buds. Among a total of 10,061 ESTs, 8,525 were of sufficient quality to analyze further. Clustering analysis revealed that 55 ％ of all ESTs (4685) occurred only once. BLASTX analysis revealed that 74％ of the ESTs had significant sequence similarity to known proteins present in the NCBI nr database. In addition, 1,265 ESTs were tentatively identified as being full-length cDNAs. Functional classification of the ESTs derived from pathogen-infected pepper leaves revealed that about 25％ were disease- or defense-related genes. Furthermore, 323 (7％) ESTs were tentatively identified as being unique to hot pepper. This study represents the first analysis of sequence data from the hot pepper plant species. Although we focused on genes related to the plant defense response, our data will be useful for future comparative studies.