Project description:The complete mitochondrial genome of the strawberry aphid Chaetosiphon fragaefolii Cockerell, 1901 (Hemiptera: Aphididae) from California, USA
Project description:Myzus persicae (green peach aphid) feeding on Arabidopsis thaliana induces a defense response, quantified as reduced aphid progeny production, in infested leaves but not in other parts of the plant. Similarly, infiltration of aphid saliva into Arabidopsis leaves causes only a local increase in aphid resistance. Further characterization of the defense-eliciting salivary components indicates that Arabidopsis recognizes a proteinaceous elicitor with a size between 3 to 10 kD. Genetic analysis using well-characterized Arabidopsis mutant shows that saliva-induced resistance against M. persicae is independent of the known defense signaling pathways involving salicylic acid, jasmonate, and ethylene. Among 78 Arabidopsis genes that were induced by aphid saliva infiltration, 52 had been identified previously as aphid-induced, but few are responsive to the well-known plant defense signaling molecules salicylic acid and jasmonate. Quantitative PCR analysis confirms expression of saliva-induced genes. In particular, expression of a set of O-methyltransferases, which may be involved in the synthesis of aphid-repellent glucosinolates, was significantly up-regulated by both M. persicae feeding and treatment with aphid saliva. However, this did not correlate with increased production of 4-methoxyindol-3-ylmethylglucosinolate, suggesting that aphid salivary components trigger an Arabidopsis defense response that is independent of this aphid-deterrent glucosinolate.
Project description:Bioinformatic prediction, deep sequencing of microRNA and expression analysis during phenotypic plasticity in the pea aphid acyrthosiphon pisum We developed high throughput Solexa sequencing and bioinformatic analyses of the genome of the pea aphid Acyrthosiphon pisum in order to identify the first miRNAs from a hemipteran insect. By combining these methods we identified 155 miRNAs including 56 conserved and 99 new miRNAs. Moreover, we investigated the regulation of these miRNAs in different alternative morphs of the pea aphid by analysing the expression of miRNAs across the switch of reproduction mode.
Project description:In plants, microRNAs (miRNAs) play a critical role in post-transcriptional gene regulation and have been shown to control many genes involved in various biological and metabolic processes. Deep sequencing technologies have facilitated identification of species-specific or lowly expressed as well as conserved or highly expressed miRNAs in plants. Strawberry is one of the most economically important fruit throughout the world.Although miRNAs have been extensively studied in the past five years, limited systematic study of miRNAs has been performed on the Fragaria genus. These results show that regulatory miRNAs exist in agronomically important strawberry and may play an important role in strawberry growth, development, and response to disease.
Project description:Soybean aphid is one of the major limiting factors for soybean production. However, the mechanism for aphid resistance in soybean is remain enigmatic, very little information is available about the different mechanisms between antibiosis and antixenosis genotypes. Here we dissected aphid infestation into three stages and used genome-wide gene expression profiling to investigate the underlying aphid-plant interaction mechanisms. Approximately 990 million raw reads in total were obtained, the high expression correlation in each genotype between infestation and non-infestation indicated that the response to aphid was controlled by a small subset of important genes. Moreover, plant response to aphid infestation was more rapid in resistant genotypes. Among the differentially expressed genes (DEGs), a total of 901 transcription factor (TF) genes categorized to 40 families were identified with distinct expression patterns, of which AP2/ERF, MYB and WRKY families were proposed to playing dominated roles. Gene expression profiling demonstrated that these genes had either similar or distinct expression patterns in genotypes. Besides, JA-responsive pathway was domination in aphid-soybean interaction compared to SA pathway, which was not involved plant response to aphid in susceptible and antixenotic genotypes but played an important role in antibiosis one. Throughout, callose were deposited in all genotypes but it was more rapidly and efficiently in antibiotic one. However, reactive oxygen species were not involved in response to aphid attack in resistant genotypes during aphid infestation. Our study helps uncover important genes associated with aphid-attack response in antibiosis and antixenotic genotypes of soybean.
Project description:Breeding day-neutral strawberry (Fragaria x ananassa Duchesne) is pivotal to extend fruit-bearing season and increase the efficiency of production. However, genetic improvement of day-neutrality by the means of molecular marker technologies remains slow due to genome complexity of octoploid strawberry. This study employs an innovative approach by integrating the Subtracted Diversity Array (SDA) technology and Bulked Segregant Analysis (BSA) to facilitate the identification of molecular markers associated with day-neutrality in octoploid strawberry. A Fragaria Discovery Panel (FDP) containing 287 features specific to strawberry genome was constructed as a platform for rapid screening of DNA polymorphism between one short day (SD) strawberry DNA bulk and three day-neutral (DN) bulks varrying in flowering strength. Differential array hybridisation patterns between the DN and SD bulks revealed a novel molecular marker, FaP2E11, closely linked to CYTOKININ OXIDASE 1 (CKX1) gene possibly involved in promoting flowering under non-inductive condition. Interestingly, a 12 bp deletion was observed within the FaP2E11 sequence cloned from SD genotypes but not DN genotypes. As cytokinin is required to induce flowering, this result indicates that full sequence of FaP2E11 and the sequence with deletion are allelic variants linked to the low enzyme activity CKX1 and the wild type alleles, respectively.