Project description:The saliva from Bemisia tabaci (MED biotype) adults was collected using an artificial feeding system and analyzed using an LC-MS/MS proteomics analysis.
Project description:The whitefly Bemisia tabaci (Gennadius) causes tremendous losses to agriculture by direct feeding on plants and by vectoring several families of plant viruses. The B. tabaci species complex comprises over 10 genetic groups (biotypes) that are well defined by DNA markers and biological characteristics. B and Q are amongst the most dominant and damaging biotypes, differing considerably in fecundity, host range, insecticide resistance, virus vectoriality, and the symbiotic bacteria they harbor. We used a spotted B. tabaci cDNA microarray to compare the expression patterns of 6,000 ESTs of B and Q biotypes under standard 25°C regime and heat stress at 40°C. Overall, the number of genes affected by increasing temperature in the two biotypes was similar. Gene expression under 25ºC normal rearing temperature showed clear differences between the two biotypes: B exhibited higher expression of mitochondrial genes, and lower cytoskeleton, heat-shock and stress-related genes, compared to Q. Exposing B-biotype whiteflies to heat stress was accompanied by rapid alteration of gene expression. For the first time, the results here present differences in gene expression between very closely related and sympatric B. tabaci biotypes, and suggest that these clear-cut differences are due to better adaptation of one biotype over another and might eventually lead to changes in the local and global distribution of both biotypes. 3 replicates comparing Q biotype under 40 degrees celsius (C) with three replicates under 25 C. The same number of replicates comparing B biotype under 40 C and 25 C, and three replicates comparing B and Q biotypes under 25 C.
Project description:The whitefly Bemisia tabaci (Gennadius) causes tremendous losses to agriculture by direct feeding on plants and by vectoring several families of plant viruses. The B. tabaci species complex comprises over 10 genetic groups (biotypes) that are well defined by DNA markers and biological characteristics. B and Q are amongst the most dominant and damaging biotypes, differing considerably in fecundity, host range, insecticide resistance, virus vectoriality, and the symbiotic bacteria they harbor. We used a spotted B. tabaci cDNA microarray to compare the expression patterns of 6,000 ESTs of B and Q biotypes under standard 25°C regime and heat stress at 40°C. Overall, the number of genes affected by increasing temperature in the two biotypes was similar. Gene expression under 25ºC normal rearing temperature showed clear differences between the two biotypes: B exhibited higher expression of mitochondrial genes, and lower cytoskeleton, heat-shock and stress-related genes, compared to Q. Exposing B-biotype whiteflies to heat stress was accompanied by rapid alteration of gene expression. For the first time, the results here present differences in gene expression between very closely related and sympatric B. tabaci biotypes, and suggest that these clear-cut differences are due to better adaptation of one biotype over another and might eventually lead to changes in the local and global distribution of both biotypes.
Project description:To investigated the stage-specific gene expression response to thiamethoxam in the Bemisia tabaci, we have designed the Agilent eArray platform to identify stage-regulated gene expression towards thiamethoxam exposure. All the B biotype Bemisia tabaci were maintained on cabbage. Thiamethoxam susceptible (TH-S) was cultured without exposure to any chemical insecticides, Thiamethoxam resistance (TH-R) strain exhibited >70-fold resistance to thiamethoxam in comparision to the TH-S strain. Eggs were incubated in 24hours collected as one sample. The fourth nymphs were collected as another sample. The one-day-old unmated adult females were collected as the third samples. Both of the samples were collected from the TH-R, TH-S strains, respectively
Project description:We investigated the transcriptional response to thiamethoxam in the Bemisia tabaci using Illumina sequencing technology. A total of 1,338 genes were differently expressed in the thiamethoxam-resistant whiteflies. All the B biotype whiteflies were maintained on cabbage. The susceptible strain (TH-S) was cultured without exposure to any chemical insecticides. Before the sample collected, almost 10,000 thiamethoxam-resistant adult whiteflies were treated with 2,000 mg/L thiamethoxam (~LC80) to eliminate the heterozygous individuals. Then the survivors were collected after 48 hours and designated as the TH-2000 sample. Then approximately 1,500 adult TH-S and TH-2000 were collected, respectively, The RNA was extracted and sequenced using Illumina HiSeq 2000.