Project description:Identification of candidate regulators of powdery mildew resistance in cucumber using comparative RNA-sequencing based transcriptome analysis
Project description:Genotyping arrays are tools for high throughput genotyping, which is required in genome-wide association studies (GWAS). Since the first cucumber genome draft was reported, genetic maps were constructed mainly based on simple-sequence repeats (SSRs) or on combinations of SSRs and other sequence-related amplified polymorphism (SRAP). In this study we developed the first cucumber genotyping array which consisted of 32,864 single nucleotide polymorphisms (SNPs). These markers cover the cucumber genome every 2.1Kb and have parents/F1 hybridizations as a training set. The training set was validated with Fludigm technology and had 98% concordance. The application of the genotyping array was illustrated by constructed a genetic map of 600 cM in length based on recombinant inbred lines (RIL) population of a 9930XGy14 cross of which compromise of 11564 SNPs. The markers collinearity between the genetic map and genome references of the two parents estimated as R2=0.97. Moreover, this comparison supports a translocation in the beginning of chromosome 5 that occurred in the lineage of 9930 and Gy14 as well as local variation in the recombination rate. We also used the array to investigate the local allele frequencies along the cucumber genome and found specific region with segregation distortions. We believe that the genotyping array together with the training set would be a powerful tool in applications such as quantitative-trait loci (QTL) analysis and GWAS.
Project description:The plant vascular system is essential for the enlarged plant stature and successful colonizzation the land by delivering resources throughout the plants and providing mechanical support. Despite several regulators of vascular patterning have been reported, how vascular system mediates stress resistance remain largely unknown. Here we identified a CsIND transcription factor that is specifically expressed in the xylem and phloem tissues in cucumber. Knock down of CsIND by RNAi lead to dwarf plants with enlarged or disorganized vascular systems in all aerial organs. The content of both auxin and jasmonic acid were increased in the CsIND-RNAi lines. Transcriptome profiling by RNA-Seq hints CsIND-regulated gene networks for defense response and vascular development. Biochemical analyses verified that CsIND directly binds to well-known vascular regulators including CsCCR1, CsMYB116, CsYAB5, CsBP and CsAUX, and physically interacts with dorsiventral patterning genes CsKAN2 and CsYAB5. Further, CsIND-RNAi plants displayed significantly enhanced tolerance to nitrogen dificency and resistance to cucumber downy mildew. Therefore, CsIND regulates vascular formation and resistance to biotic and abiotic stresses in cucumber, through the combinarory interactions with well-known vascular regulaors and hormone metabolism and signaling pathways.
Project description:Transcriptomic analysis of LaeA-deletion and overexpression LaeB in LaeA deletion strains in fungus Beauveria bassiana Examination of differential gene expressions by Beauveria bassiana wild type, LaeA-deletion and overexpression LaeB in LaeA deletion strains in fungus Beauveria bassiana
Project description:BbTdp1 is a novel protein with the function of regulating conidium and blastospore yields, fungal morphological changes and pathogenicity in Beauveria bassiana.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of gene expression profiles of cucumber under short-term chilling stress. The goals of this study are to transcriptome analysis of cucumber leaves under chilling stress. Methods: mRNA profiles of seedlings exposed to an air temperature of 6°C in the absence of light at 0, 2, 6, and 12 h were generated by deep sequencing, in triplicate, using Illumina Hiseq platform. The reference genome and gene model annotation files were downloaded from the genome website (http://cucurbitgenomics.org/). An index of the reference genome was built using Bowtie v.2.2.3 and paired-end clean reads were aligned to the reference genome using TopHat v.2.0.12. qRT–PCR validation was performed using SYBR Green assays. Results: A total of 55.7 million clean reads was generated. Based on the threshold values of absolute value of log2 ratio ≥ 1 and FDR ≤ 0.05, a total of 2113 DEGs was identified at three time points (2, 6, and 12 h). A total of 30 genes was detected at all time points. The number of DEGs increased with time. In total, 100 TFs from 22 families in three subsets were detected. And 19 kinase families were identified in three subsets. The DEGs identified by RNA sequencing were confirmed by qRT-PCR analysis, indicating that the data were reliable. These findings provide information that can be useful for investigating the molecular mechanisms underlying the response to chilling stress in cucumber and other plants. Conclusions: The results presented here reveal changes in the transcriptome profile of cucumber in response to chilling stress. Exposure to a low temperature induced genes involved in hormone regulation, lipid metabolism, and photosynthesis, including NAC, WRKY, AP2/ERF, ERD, MYB as well as zinc finger TFs and protein kinases such as receptor-like protein kinase, MAPK, and CDK. Most TFs were upregulated whereas CDKs were downregulated. These findings provide information that can be useful for investigating the molecular mechanisms underlying the response to chilling stress in cucumber and other plants.
Project description:Cucumber (Cucumis sativus L.) is an economically important vegetable crop distributed in over 80 countries. Downy mildew (DM) caused by the obligate oomycete Pseudoperonospora cubensis is especially destructive in cucumber production. So far, few studies on the changes in proteomes during the P. cubensis infection have been performed. Using a newly developed TMT-LC-MS/MS analysis, the proteomes of DM-resistant variety ‘ZJ’ and DM-susceptible variety ‘SDG’ under the P. cubensis infection were investigated. In total, 6400 proteins were identified, 5629 of which were quantified. The differential accumulated proteins (DAPs) exhibited various biological functions and diverse subcellular localizations. KEGG enrichment analysis showed that various metabolic pathways were significantly altered under the P. cubensis infection, such as terpenoid backbone biosynthesis, and selenocompound metabolism in ZJ, and starch and sucrose metabolism in SDG. Most of the enzymes associated with terpenoid backbone synthesis were significantly accumulated in ZJ rather than in SDG, suggesting that pathogen-induced terpenoids accumulation might play an important role in the resistance against P. cubensis infection. Furthermore, a number of pathogenesis-related proteins and heat shock proteins were identified as DAPs, suggesting that DM resistance was controlled by a complex network. Our data allowed us to identify and screen more potential proteins related to the DM resistance.