In every ecosystem there is a transfer of energy between individuals belonging to different trophic levels, that is, to the different levels related to nutrition. The first trophic level is that of the autotrophs, that is the producer organisms (such as plants) capable of generating the organic substance necessary for their nutritional needs, starting from inorganic molecules and an energy source. From the second trophic level there are consumers, who need organic matter to feed themselves. Consumers of different levels belong to the class of insects: phytophages (primary consumers), which feed on plant substances, and entomophages (secondary consumers) which feed on other insects. The latter can be classified into predators, which feed on the prey after killing it, and parasitoids, which colonize the host insect causing its death at the end of its development cycle. The female of the parasitoid lays her egg inside or on the host’s body and at the same time injects substances, including a poison consisting of a complex mixture of proteins, capable of regulating the physiology of the host, making it a suitable environment for the development of one’s offspring.
In the last decade, “omics” approaches, such as those of genomics or proteomics, have made it possible to identify and characterize the poison proteins of various parasitoids at a functional level. Our research, through an integrated omic method, has identified the components of the venom of Torymus sinensis, parasitoid of Dryocosmus kuriphilus, itself a parasite of the chestnut tree. The combination of the data obtained from the different approaches (the computer analysis of the transcriptome, i.e. the expression of the genes, of the RNA messengers of the gland responsible for the production of the venom combined with the proteomic analysis, by means of mass spectrometry on the venom of Torymus sinensis) allowed to identify 143 proteins, among which the most abundant fall into the macro-category of hydrolases, similarly to what is found in the poisons of other parasitoids. All proteins are involved in the complex parasite syndrome, with negative effects on the immune system, metabolism, physiological and developmental processes of the host.
Although further studies are needed, the information obtained is an excellent starting point to understand, at the molecular and functional level, the role of venom in the interactions between host and parasitoid and also to identify genes and molecules useful for the development of new control strategies. in integrated biological pest management and applications in the biomedical or industrial fields. The approach used is highly innovative because it allows the identification of proteins of organisms not present in the databases. This is especially true for insects, which with over a million species are the organisms with the highest level of biodiversity and as such are an extraordinary and almost inexhaustible source of molecules useful for humans and the environment.
P. Falabella et al., An integrated transcriptomic and proteomic approach to identify the main Torymus sinensis venom components, Scientific reports (2021)