Project description:A comparative study to determine the pepper leaf curl virus resistance machanism between resistant and susceptible genotypes at three leaf stage. To study the molecular mechanism of pepper leaf curl virus (PepLCV) resistance, pepper plants were exposed to PepLCV through artificial inoculation and hybridization on Agilent tomato microarrays. The expression analysis of PepLCV resistant and susceptible genotypes after artificial inoculation at three leaf stage showed that the resistance against PepLCV is due to sum of expression of hundreds of genes at a particular stage. Tomato microarrays consisting of 43,803 probes were used for whole genome expression analysis of chilli peppers for resistance against PepLCV. Transcripts from the leaves of resistant (BS-35) and susceptible plants (IVPBC-535) were compared in response to PepLCV inoculation at three leaf stage.
Project description:We used a high-throughput proteomics method called label-free to compare protein abundance across a pepper CMS line and its isogenic maintainer line.This study explained the mechanisms of cytoplasmic male sterility and contribute to the improvement of pepper hybrid breeding.
Project description:In this study, we used the illumina high throughput sequencing approach (Sequencing-By-Synthesis, or SBS) to develop the sequence resource of black pepper. To identify micro RNAs functioning in stress response of the black pepper plant, small RNA libraries were prepared from the leaf and root of Phytophthora capsici infected plants, leaves from drought stressed and control plants. Overall design: Stress responsive small RNAome profiling from black pepper
Project description:In this study, we have evaluated the proteomic changes that occur in Piper nigrum L.(black pepper) after infection by the pathogen Phytophthora capsici. We report novel leaf proteins from black pepper identified by an integrated transcriptome-assisted label-free quantitative proteomics pipeline. Several previously described methods were used to create this data set. Detached leaves were inoculated with either mock treatment, or the oomycete pathogen and small tissue samples only around the site of inoculation were collected for protein sample preparations. In order to quantify protein abundance in the samples being compared, we used a label free method of spiking samples with a known ratio of pre-digested peptide samples to normalize endogenous protein abundance in the MS detection. Our study attempts to explain the basal immune components of black pepper when challenged with P. capsici.
Project description:To facilitate the functional annotation of the pepper genome, analysis of miRNAs was performed for the sequenced data from five small RNA libraries described above, representing five different tissues. Starting with a set of 5,436 plant mature miRNA sequences available in miRBase, we annotated with high confidence 176 pepper miRNAs from 64 families, of which 30 families are computationally predicted to target TFs, suggesting important roles of these miRNA families in post-transcriptional gene regulation and transcription networks consistent with previous findings. To identify genomic regions generating small RNAs, we applied previously described analytical strategies to five small RNA libraries from different tissues. Developing roots, stems and mature leaves were collected from plants grown in soil in a green house at 22 °C with a 16 hr light cycle and harvested from plants at full-bloom stage. Mature plants were harvested for fully open flowers. Additional flowers were allowed to self-pollinate and fruit was harvested in the breaker stage (thirty days after pollination when the fruit was turning red). Total RNA for different tissues was isolated from the frozen root samples by using the Trizol Reagent (Invitrogen) according to manufacturer’s instructions, and libraries were constructed using the Small RNA Sample Prep Kit (Illumina, San Diego, CA) as previously described, then sequenced on an Illumina HiSeq2000 system.
Project description:Background The set of all mRNA molecules present in a cell constitute the transcriptome. The transcriptome varies depending on cell type as well as in response to internal and external stimuli during development. Chili pepper is an economically and culturally important horticultural crop as well as a good model for the study of secondary metabolism during fruit development. Here we present a study of the changes that occur in the transcriptome of chili pepper fruit during development and ripening. Results RNA-Seq was used to obtain transcriptomes of whole Serrano-type chili pepper fruits (Capsicum annuum L.; 'Tampiqueno 74') collected at 10, 20, 40 and 60 days after anthesis (DAA). 15,550,468 Illumina MiSeq reads were assembled de novo into 34,066 chili genes. We classified the expression patterns of individual genes as well as genes grouped into Biological Process ontologies and Metabolic Pathway categories using statistical criteria. For the analyses of gene groups we added the weighted expression of individual genes. This method was effective in interpreting general patterns of expression changes and increased the statistical power of the analyses. Subsets of genes were expressed only at a single time point sampled (1,278, 1,596, 1,519 and 1,583 genes at 10, 20, 40 and 60 DAA, respectively). We also estimated the variation in diversity and specialization of the transcriptome during chili pepper development. Approximately 17% of genes exhibited a significant change of expression in at least one of the intervals sampled. In contrast, significant differences in approximately 63% of the Biological Processes and 80% of the Metabolic Pathways studied were detected in at least one interval. Confirming previous reports, genes related to capsaicinoid and ascorbic acid biosynthesis were significantly upregulated at 20 DAA while those related to carotenoid biosynthesis were highly expressed in the last period of fruit maturation (40-60 DAA). Our RNA-Seq data was validated by examining the expression of nine genes involved in carotenoid biosynthesis by qRT-PCR. Conclusions In general, more profound changes in the chili fruit transcriptome were observed in the intervals between 10 to 20 and 40 to 60 DAA. The last interval, between 40 to 60 DAA, included 49% of all significant changes detected, and was characterized predominantly by a global decrease in gene expression. This period signals the end of maturation and the beginning of senescence of chili pepper fruit. The transcriptome at 60 DAA was the most specialized and least diverse of the four states sampled. Overall design: RNA-seq libraries of whole chili pepper (Capsicum annuum Serrano 'Tampiqueno 74' landrace) were prepared from fruits at 10, 20, 40 and 60 days after anthesis (DAA). Two biological replicates of each fruit state were prepared (8 libraries in total). Libraries were sequenced in the Illumina MiSeq platform. The title of the libraries are: <DAA>repbio<#> where <DAA> are the days after anthesis (10, 20, 40 or 60) and <#> is the number of biological replicate, 1 or 2. Details follow. Biological material and RNA extraction Capsicum annuum Serrano 'Tampiqueno 74' seeds were germinated and the seedlings were cultivated until maturity under greenhouse conditions in a completely randomized experimental design at Cinvestav-Unidad Irapuato (Guanajuato, Mexico). The plants were grown during the spring and summer, and individual flowers were tagged at anthesis. Chili pepper fruits were randomly collected from different plants at 10, 20, 40 and 60 DAA. After sampling, the fruits were cleaned with ethanol immediately frozen in liquid nitrogen and stored at -80C until further use. For total RNA extractions, 10 fruits at the 10 DAA developmental stage and 5 fruits from each of the 20, 40 and 60 DAA stages were randomly selected from the pool of all harvested fruits. Whole fruits (pericarp, placenta and seeds) were ground in liquid nitrogen with a mortar and pestle to form a fine uniform powder. Samples were mixed vigorously and 100 mg aliquots were measured for each RNA extraction. The process was repeated with different sets of fruits in order to obtain two independent biological replicates at each developmental stage. A NucleoSpin RNA Plant kit (Macherey-Nagel) was used for total RNA extraction and contaminating genomic DNA was removed by DNase I (Macherey-Nagel) treatment following the manufacturers' protocols. Total RNA concentration was quantified using a NanoDrop ND-1000 spectrophotometer (Nano-Drop, Wilmington, DE, USA) and RNA quality was evaluated by gel electrophoresis on 1.0% denaturing agarose gels. In addition, aliquots of RNA were run on an Agilent 2100 Bioanalyzer using RNA 6000 chips (Agilent, Santa Clara, CA, USA) to test the RNA integrity number (RIN). All eight samples had RIN values higher than 8.7. Thirty μg of total RNA from each of the eight samples (two biological replicates of four fruit developmental stages) was used for cDNA library preparation. Library construction and sequencing The eight total RNA samples (two biological replicates from chili pepper fruits at 10, 20, 40 and 60 DAA) were prepared for RNA-Seq using the Illumina TruSeq RNA Sample Preparation v2 Guide following the manufacturer's instructions. Briefly, mRNA was purified from 20μg of total RNA using poly-T oligo- attached magnetic beads using two rounds of purification. During the second elution of the poly-A RNA, mRNA was fragmented using divalent cations under elevated temperature and primed for cDNA synthesis. The cleaved RNA fragments were primed with random hexamers and reverse transcribed into single-stranded cDNA using reverse transcriptase. In the next step, the RNA template was removed and the complementary cDNA strand was synthesized using RNAse H and DNA polymerase I, respectively. The overhangs that resulted from fragmentation were polished into blunt ends using an End Repair Mix (consisting of T4 DNA polymerase, Klenow fragment and T4 polynucleotide kinase). A single T nucleotide was added on the 3' end of the adapter for ligating the adapter to the cDNA fragments. Indexing adapters were ligated to the ends of the cDNAs using T4 DNA ligase, preparing them for hybridization onto a flow cell. Finally, the DNA fragments with adapter molecules at both ends were amplified by PCR to enrich the amount of DNA in the library. PCR was performed with a PCR primer cocktail that anneals to the ends of the adapters. Quantity and quality of the DNA libraries was assessed using Agilent DNA-1000 chips on an Agilent 2100 Bioanalyzer. The 8 cDNA libraries were pooled and simultaneously sequenced from both 5’ and 3’ ends using the Illumina MiSeq System platform according to the manufacturer's instructions. We performed three sequencing runs (technical replicates) with the aim of increase the sequencing depth. 150 bp paired-end reads were obtained in each sequencing run. Fluorescent image processing, base-calling and quality value calculations for each of the three runs were performed using Illumina MiSeq Control Software. Data were deposited at the NCBI (GEO database under series record GSE54123).