ABSTRACT: Global Analysis of the Transcriptional Response of Whitefly to Entomopathogenic Fungi Beauveria bassiana Reveals New Insights on Host-Pathogen Interactions
Project description:We investigated the transcriptional response of invasive Mediterranean (MED) species of the whitefly B. tabaci complex (commonly referred to as Q biotype) to entomopathogenic fungi Beauveria bassiana using Illumina sequencing technology.
Project description:We investigated the transcriptional response of invasive Mediterranean (MED) species of the whitefly B. tabaci complex (commonly referred to as Q biotype) to entomopathogenic fungi Beauveria bassiana using Illumina sequencing technology. Nearly 1,000 of control whiteflies, 48h fungal-induced whiteflies and 72h fungal-induced whiteflies were collected, respectively.
Project description:The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and the viruses it transmits, are a major constraint to vegetable crops, worldwide. Although the whitefly is usually controlled using chemical pesticides, biological control agents constitute an important component in integrated pest management programs. One of these agents is the wasp Eretmocerus mundus (Mercet) (Hymenoptera: Aphelinidae). E. mundus lays its egg on the leaf underneath the pupa of B. tabaci. First instars of the wasp hatch and penetrate the whitefly larvae. Initiation of parasitization induces the host to form a cellular capsule around the parasitoid. Around this capsule, epidermal cells multiply and thick layers of cuticle are deposited. The physiological and molecular processes underlying B. tabaci-E. mundus interactions have not been investigated so far. We have used a cDNA microarray containing 6,000 expressed sequence tags (ESTs) from the whitefly genome to study the parasitoid-whitefly interaction. We compared RNA samples collected across two time points of the parasitization process: when the parasitoid first instar started the penetration process and once it had fully penetrated the host. The results clearly indicated that genes known to be part of the defense pathways described in other insects are also involved in the response of B. tabaci to parasitization by E. mundus. Some of the responses observed included the repression of a serine protease inhibitor (serpin) and the induction of a melanization cascade. A second set of genes that strongly responded to parasitization included bacterial genes encoded by whitefly symbionts. Quantitative real-time PCR and FISH analyses showed that proliferation of Rickettsia, a facultative secondary symbiont, was strongly induced following the initiation of the parasitization process, a result that supported previous reports suggesting that endosymbionts may be involved in the insect host resistance to various environmental stresses. This is the first study examining the transcriptional response of a hemipteran insect to the attack of a biological control agent (Hymenopterous parasitoid), using a new genomic approach developed for this insect pest. The defense response in B. tabaci seems to resemble that of model organisms such as Drosophila melanogaster. Moreover, endosymbionts of B. tabaci seem to play a role in the response to parasitization, and this is supported by previously published results from aphids. Keywords: time course
Project description:The ascomycete fungus Beauveria bassiana is a pathogen of hundreds of insect species and is commercially produced as an environmentally friendly mycoinsecticide. Genome-wide insight into the infection of the fungi is critical for genetic improvement of fungal insecticides but has been poorly explored. We constructed three transcriptomes of Beauveria bassiana at 24, 48 and 72 hours post treatment of infection (BbI) and of control (Bbc).
Project description:Tomato leafminer (Tuta absoluta) is a major pest of solanaceous plant species and causes heavy economic losses to the tomato crop. T. absoluta have been developed resistance to many chemical insecticides and have serious impacts on human health as well as environment. To overcome the ill effects of insecticides, ecofriendly approachis needed and among various biological microbes, entomopathogenic fungi is reliable and cost effective. The entomopathogenic fungi, like Beauveria bassiana and Purpureocillium lilacinum have ability to control pest population. The present study was conducted to study the interaction of B. bassiana and P. lilacinum at proteomic level to understand post infection effects. The analysis showed that in fourth instar larvae of T. absoluta, and the 442 and 423 proteins were significantly dysregulated upon infection with P. lilacinum and B. bassiana respectively. The present study concluded entomopathogenic fungal infection decline the immune system of T. absoluta larvae and can be adopted in for control of T. absoluta insect pest.
Project description:The whitefly Bemisia tabaci is a notorious pest of worldwide agriculture. It is believed to secrete saliva to counter plant defenses, but the underlying mechanism remains to be elucidated. Here, we characterize the gene/protein repertoires of B. tabaci salivary glands and secreted saliva by transcriptomic and LC–MS/MS analysis. A total of 698 salivary gland-higher expressed unigenes, as well as 172 saliva proteins are identified. Comparative analysis of the saliva composition in different arthropod species illustrates that proteins associated with binding, hydrolysis and oxidation-reduction are widely distributed in herbivorous saliva. There are 74 saliva proteins exclusively identified in B. tabaci, with 34 of them being B. tabaci-specific. In addition, eleven B. tabaci-specific saliva proteins plastically regulated in response to different diets, which might be associated with wide host range of this pest. Our results gain insight into whitefly–plant interactions, and provide a good resource for functional characterization of effectors
Project description:The whitefly, Bemisia tabaci, a notorious agricultural pest, has complex relationships with diverse microbes. It recognizes and degrades pathogens, as other insects do, and also relies on endosymbionts for its survival. Both types of interaction have received great attention, because of their potential importance in developing novel whitefly control technologies. The recent developments in RNA-seq technology allows us to perform a comprehensive investigation of a whitefly’s defense responses after it has ingested the pathogen, Pseudomonas aeruginosa. Compared to uninfected whiteflies, 6 and 24 hour post-infected (hpi) whiteflies showed 1,348 and 1,888 differentially expressed genes, respectively. Functional analysis highlighted the involvement of mitogen associated protein kinase (MAPK) pathway in host-defense regulation. Three knottin-like antimicrobial peptide genes and several components of the humoral and cellular immune response were also activated, indicating that key immune elements recognized in other insect species are also important for the host response of B. tabaci. Our data also suggest that intestinal stem cell mediated epithelium renewal might be an important component of the whitefly’s defense against oral bacterial infection. In addition, we also show stress responses to be an essential component of the defense system. We identify for the first time the key immune-response elements utilized by B. tabaci against bacterial infection. This provides a framework for future research into the complex interactions between whiteflies and microbes.