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The complex microbial community living in the hindgut of lower termites includes prokaryotes, flagellates, yeasts, and filamentous fungi. Many microorganisms are found in the termite gut, but only a few are thought to be involved in symbiotic association to participate in cellulose digestion. Proteomics provides analyses from both taxonomical and functional perspectives. We aimed to identify symbiont diversity in the gut of Reticulitermes santonensis (Feytaud), via complementary electrospray ionization associated to ion trap tandem mass spectrometry (LC-MS/MS) and two-dimensional gel electrophoresis associated to matrix-assisted laser desorption-ionization-time-of-flight mass spectrometry analysis. One specific challenge to the study of lower termites is the relatively few data available on abundant symbiotic flagellates. Analysis based on LC-MS/MS revealed few protein families showing assignments to eukaryotes and the taxonomic origin of highly represented actins could not be established. Tubulins proved to be the most suitable protein family with which to identify flagellate populations from hindgut samples using LC-MS/MS, compared with other protein families, although this method targeted few prokaryotes in our assay. Similarly, two-dimensional gel electrophoresis associated to matrix-assisted laser desorption-ionization-time-of-flight mass spectrometry did not succeed in identifying flagellate populations, but did permit the identification of most of the prokaryotic components of the symbiotic system. Finally, fungi and yeasts were identified by both methods. Owing to the lack of sequenced genes in flagellates, targeting tubulins for LC-MS/MS could allow fingerprints of flagellate populations to be established. Experimental and technical improvements might increase the efficiency of identification of prokaryotic populations in the near future, based on metaproteomic development. [ABSTRACT FROM AUTHOR]

Secondary plant substances, also called allelochemicals, play a major role in pest infestations. Glucosinolates (GLS) and their degradation products are powerful phagostimulants for herbivores feeding on Brassicaceae and deter the noncrucifer feeders but are tolerated by some generalist phytophagous insects such as the peach-potato aphid, Myzus persicae Sultzer. Do the allelochemical substances only effect the herbivores or do they also influence the predators of the pest? Broad bean, Vicia faba L. (GLS free), oilseed rape, Brassica napus L. (low GLS level), and white mustard, Sinapis alba L. (high GLS level), were used in this work as host plant for the prey. Although the two latter Brassicaceae species had positive effects on aphid reproductive rates, host plants displayed mixed influences on the performance of the predaceous twospotted lady beetle, Adalia bipunctata L. Both rape and mustard shortened development duration and increased adult weight of the twospotted lady beetle. No significant difference of lady beetle mortality was observed, depending on the prey host plant. Whereas, rape-fed M. persicae enhanced larger egg production and larvae emergence, mustard-fed M. persicae induced lower fecundity and egg viability of the beetles. Fitness of M. persicae on high GLS plant-fed A. bipunctata was lower than the other plants. Biological parameters of aphid predators are closely linked to chemical composition of Brassicaceae species. This work on allelochemical impact gave opportunities to better understand interactions of the plant-aphid-lady beetle tritrophic model and demonstrated that successful biological control of pests must integrate the environmental aspects of each trophic level. [ABSTRACT FROM AUTHOR]