Rickettsia influences thermotolerance in the whitefly Bemisia tabaci B biotype
Rickettsia influences thermotolerance in the whitefly Bemisia tabaci B biotype
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DOI：
10.1111/j.1744-7917.2010.01396.x
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发表时间：
2011-02-01
期刊：
影响因子：
4
通讯作者：
Ghanim, Murad
中科院分区：
文献类型：
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作者：
Brumin, Marina;Kontsedalov, Svetlana;Ghanim, Murad
烟粉虱携带专性共生细菌粉虱，以及几种次级共生体，包括立克次体、汉米尔顿氏体、沃尔巴克氏体、砷菌、Cardinium和Fritschea，其功能尚不清楚。在以色列，在B的B和Q中均发现了立克次体。虽然所有其他次级共生体都位于细菌组中，但立克次体可以占据昆虫的大部分体腔。我们测试了立克次体是否影响B的生物学。研究人员发现，与不含立克次体的种群相比，将含立克次体的种群暴露在不断升高的温度下，显著提高了其对达到40摄氏度的热休克的耐受性。热休克耐受性的增加与热休克蛋白基因表达的特异性诱导无关;然而，通过定量实时聚合酶链反应和荧光原位杂交分析评估，它与立克次体数量的减少有关。为了评估立克次体减少时耐热性的原因，我们测试了其存在是否与耐热性所需基因的诱导有关。我们发现，在正常25摄氏度的饲养温度下，含立克次体的群体中与应激反应相关的基因（例如细胞骨架基因）被诱导。因此，在B.在正常条件下，烟粉虱诱导耐热性所需基因的表达，而在高温下则间接导致这种耐受性。
The whitefly Bemisia tabaci harbors Portiera aleyrodidarum, an obligatory symbiotic bacterium, as well as several secondary symbionts, including Rickettsia, Hamiltonella, Wolbachia, Arsenophonus, Cardinium and Fritschea, the function of which is unknown. In Israel, Rickettsia is found in both the B and Q of B. tabaci biotypes, and while all other secondary symbionts are located in the bacteriomes, Rickettsia can occupy most of the body cavity of the insect. We tested whether Rickettsia influences the biology of B. tabaci and found that exposing a Rickettsia-containing population to increasing temperatures significantly increases its tolerance to heat shock that reached 40 degrees C, compared to a Rickettsia-free population. This increase in tolerance to heat shock was not associated with specific induction of heat-shock protein gene expression; however, it was associated with reduction in Rickettsia numbers as was assessed by quantitative real-time polymerase chain reaction and fluorescence in situ hybridization analyses. To assess the causes for thermotolerance when Rickettsia is reduced, we tested whether its presence is associated with the induction of genes required for thermotolerance. We found that under normal 25 degrees C rearing temperature, genes associated with response to stress such as cytoskeleton genes are induced in the Rickettsia-containing population. Thus, the presence of Rickettsia in B. tabaci under normal conditions induces the expression of genes required for thermotolerance that under high temperatures indirectly lead to this tolerance.