• Current Research on Agriculture and Life Sciences
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• 제30권2호
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• pp.124-130
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• 2012

Sweetpotato whitefly, Bemisia tabaci, is a vector of more than 100 plant-diseased viruses, as well as a serious pest of various horticultural plants. This species harbors a primary endosymbiont Portiera along with several secondary endosymbionts such as Cardinium and Hamiltonella. We investigated whether or not TYLCV acquisition alters the densities of endosymbionts in the body of B. tabaci using quantitative real-time PCR. Our results showed that the densities of both Cardinium and Hamiltonella, but not Portiera, increased upon acquisition of TYLCV. In addition, expression of GroEL, a molecular chaperone produced by Hamiltonella, was significantly upregulated in TYLCV-infected whiteflies. Our results suggest that endosymbionts may play an important role in TYLCV transmission mechanism within the body of B. tabaci.

• 한국미생물·생명공학회지
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• 제48권3호
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• pp.373-382
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• 2020

Candidatus Carsonella ruddii is an endosymbiont that resides in specialized cells within the body cavity of plant sap-feeding insects called psyllids. The establishment of symbiotic associations is considered one of the key factors for the evolutionary success of psyllids, as it may have helped them adapt to imbalanced food resources like plant sap. Although C. ruddii is defined as a psyllid primary symbiont, the genes for some essential amino acid pathways are absent. Complete genome sequences of several C. ruddii strains have been published. However, in-depth intra-species comparison of C. ruddii strains has not yet been done. This study therefore aimed to perform a comparative genome analysis of six C. ruddii strains, allowing the interrogation of phylogenetic group, functional category of genes, and biosynthetic pathway analysis. Accordingly, overall genome size, number of genes, and GC content of C. ruddii strains were reduced. Phylogenetic analysis based on the whole genome proteomes of 30 related bacterial strains revealed that the six C. ruddii strains form a cluster in same clade. Biosynthetic pathway analysis showed that complete sets of genes for biosynthesis of essential amino acids, except tryptophan, are absent in six C. ruddii strains. All genes for tryptophan biosynthesis are present in three C. ruddii strains (BC, BT, and YCCR). It is likely that the host may depend on a secondary symbiont to complement its deficient diet. Overall, it is therefore possible that C. ruddii is being driven to extinction and replacement by new symbionts.

• Current Research on Agriculture and Life Sciences
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• 제30권2호
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• pp.115-123
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• 2012

Whiteflies harbor several secondary endosymbionts, which are maternally inherited from mother to offspring, that have major effects on host preferences, biology, and evolution. Here, we identified Wolbachia bacteria in sweetpotato whitefly (Bemisia tabaci) as well as whitefly popluations from other countries by comparison of 16S rDNA sequences. Wolbachia were detected in all tested indigenous B. tabaci populations (Bangladesh, Myanmar, Nepal, and the Philippines) as well as Q1 biotype of Korea, whereas they were absent from B biotype of Korea and Q biotype of China. Wolbachia were also detected in all five tested Aleurodicus dispersus populations as well as Tetraleurodes acaciae, whereas they were not detected in all seven Trialeurodes vaporariorum populatuions. In addiiton, Wolbachia were detected in parasitic wasp (Encarsia formosa) of B. tabaci as well as honeybee (Apis mellifera). Among the 19 whitefly populations from different countries, our analysis identified four phylogenetic groups of Wolbachia, thereby demonstrating the high diversity of this genus. Wolbachia phylogeny suggests a correlation of geographical range with ecological variation at the species level.