Publicação
The reciprocal interaction between Wolbachia and host-plant specialization in spider mites
| Resumo: | It is currently becoming increasingly clear that bacterial endosymbionts affect arthropod-plant interactions. For instance, they may act as nutritional mutualists, directly supplying their host with nutrients or enzymes insufficient in their plant diet or enabling them to manipulate plant physiology, such as anti-herbivore defenses, for their own benefit. Reciprocally, plants can influence the effects of symbionts on their hosts, specifically through the modification of their densities, a key factor for both symbiont maintenance and spread within natural populations. Here, we studied the tripartite interaction between the two-spotted spider mite Tetranychus urticae, a polyphagous agricultural pest, five of its natural host plants and its endosymbionts Wolbachia, Rickettsia and Cardinium, which can manipulate the reproduction of their hosts, and/or be mutualists. The prevalence of these endosymbionts is highly variable (ranging from 0 to 100%) in natural populations of T. urticae worldwide, although the factors affecting their distribution are still largely unknown. We first investigated whether Wolbachia affects the performance of T. urticae on different host plants. Wolbachia infection was found to be detrimental, beneficial, or neutral on eggs hatching rate depending on the host plant, and these results were unaffected by the mites’ rearing history (i.e. laboratory maintenance on different plants). All other life history traits were affected only by the plant species, or by Wolbachia infection. Subsequently, we evaluated the effect of the same plants on endosymbiont prevalence in natural populations of T. urticae in Portugal (5 replicates per host plant). The prevalence of Wolbachia and Rickettsia varied with the host plants, but not that of Cardinium. Interestingly, the plants leading to the lower prevalence of Wolbachia in natural populations of T. urticae are also those in which Wolbachia infection results in lower eggs hatchability. These results suggest that host plants may play an important role in endosymbionts spread in T. urticae populations. Conversely, T. urticae host-plant colonization may hinge on their cortege of endosymbionts. |
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| Autores principais: | Santos, Joaquim Luís Fernandes dos |
| Assunto: | Tetranychus urticae Wolbachia Planta-hospedeira Interação tripartida Endossimbionte Teses de mestrado - 2016 |
| Ano: | 2016 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | It is currently becoming increasingly clear that bacterial endosymbionts affect arthropod-plant interactions. For instance, they may act as nutritional mutualists, directly supplying their host with nutrients or enzymes insufficient in their plant diet or enabling them to manipulate plant physiology, such as anti-herbivore defenses, for their own benefit. Reciprocally, plants can influence the effects of symbionts on their hosts, specifically through the modification of their densities, a key factor for both symbiont maintenance and spread within natural populations. Here, we studied the tripartite interaction between the two-spotted spider mite Tetranychus urticae, a polyphagous agricultural pest, five of its natural host plants and its endosymbionts Wolbachia, Rickettsia and Cardinium, which can manipulate the reproduction of their hosts, and/or be mutualists. The prevalence of these endosymbionts is highly variable (ranging from 0 to 100%) in natural populations of T. urticae worldwide, although the factors affecting their distribution are still largely unknown. We first investigated whether Wolbachia affects the performance of T. urticae on different host plants. Wolbachia infection was found to be detrimental, beneficial, or neutral on eggs hatching rate depending on the host plant, and these results were unaffected by the mites’ rearing history (i.e. laboratory maintenance on different plants). All other life history traits were affected only by the plant species, or by Wolbachia infection. Subsequently, we evaluated the effect of the same plants on endosymbiont prevalence in natural populations of T. urticae in Portugal (5 replicates per host plant). The prevalence of Wolbachia and Rickettsia varied with the host plants, but not that of Cardinium. Interestingly, the plants leading to the lower prevalence of Wolbachia in natural populations of T. urticae are also those in which Wolbachia infection results in lower eggs hatchability. These results suggest that host plants may play an important role in endosymbionts spread in T. urticae populations. Conversely, T. urticae host-plant colonization may hinge on their cortege of endosymbionts. |
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