Mahadav Assaf, Kontsedalov Svetlana, Czosnek Henryk, Ghanim Murad
The Hebrew University of Jerusalem, The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Plant Sciences and Genetics in Agriculture and the Minerva Otto Warburg Center for Agricultural Biotechnology, Rehovot, Israel.
Insect Biochem Mol Biol. 2009 Oct;39(10):668-76. doi: 10.1016/j.ibmb.2009.08.002. Epub 2009 Aug 14.
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 6000 ESTs of B and Q biotypes under standard 25 degrees C regime and heat stress at 40 degrees C. Overall, the number of genes affected by increasing temperature in the two biotypes was similar. Gene expression under 25 degrees C 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.
烟粉虱Bemisia tabaci（Gennadius）通过直接取食植物以及传播多种植物病毒科，给农业造成了巨大损失。烟粉虱物种复合体包含10多个遗传组（生物型），这些遗传组通过DNA标记和生物学特征得到了很好的界定。B型和Q型是最具优势且危害最大的生物型，在繁殖力、寄主范围、抗药性、病毒传播能力以及所携带的共生细菌等方面存在很大差异。我们使用斑点烟粉虱cDNA微阵列，比较了B型和Q型生物型在25摄氏度标准条件和40摄氏度热胁迫下6000个ESTs的表达模式。总体而言，两种生物型中受温度升高影响的基因数量相似。在25摄氏度正常饲养温度下，两种生物型的基因表达存在明显差异：与Q型相比，B型线粒体基因表达较高，但细胞骨架、热休克和胁迫相关基因表达较低。将B型生物型烟粉虱暴露于热胁迫下会伴随着基因表达的快速改变。本文的结果首次揭示了亲缘关系极近且同域分布的烟粉虱生物型之间的基因表达差异，并表明这些明显差异是由于一种生物型比另一种生物型具有更好的适应性，最终可能导致两种生物型在局部和全球分布上的变化。
