Tribolium castaneum is a member of the most species-rich eukaryotic order, a powerful model organism for the study of generalized insect development, and an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved the ability to interact with a diverse chemical environment, as shown by large expansions in odorant and gustatory receptors, as well as P450 and other detoxification enzymes. Development in Tribolium is more representative of other insects than is Drosophila, a fact reflected in gene content and function. For example, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, some being expressed in the growth zone crucial for axial elongation in short-germ development. Systemic RNA interference in T. castaneum functions differently from that in Caenorhabditis elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.

https://serval.unil.ch/resource/serval:BIB_A924C01B36F7.P001/REF.pdf

The genome of the model beetle and pest Tribolium castaneum.

Tribolium castaneum is a member of the most species-rich eukaryotic order, a powerful model organism for the study of generalized insect development, and an important pest of stored agricultural products We describe its genome sequence here This omnivorous beetle has evolved the ability to interact with a diverse chemical environment, as shown by large expansions in odorant and gustatory receptors, as well as P450 and other detoxification enzymes Development in Tribolium is more representative of other insects than is Drosophila, a fact reflected in gene content and function For example, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, some being expressed in the growth zone crucial for axial elongation in short-germ development Systemic RNA interference in T castaneum functions differently from that in Caenorhabditis elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control

The genome of the model beetle and pest Tribolium castaneum

Preservative agents in foods. Mode of action and microbial resistance mechanisms.

Colletotrichum species are fungal pathogens that devastate crop plants worldwide. Host infection involves the differentiation of specialized cell types that are associated with penetration, growth inside living host cells (biotrophy) and tissue destruction (necrotrophy). We report here genome and transcriptome analyses of Colletotrichum higginsianum infecting Arabidopsis thaliana and Colletotrichum graminicola infecting maize. Comparative genomics showed that both fungi have large sets of pathogenicity-related genes, but families of genes encoding secreted effectors, pectin-degrading enzymes, secondary metabolism enzymes, transporters and peptidases are expanded in C. higginsianum. Genome-wide expression profiling revealed that these genes are transcribed in successive waves that are linked to pathogenic transitions: effectors and secondary metabolism enzymes are induced before penetration and during biotrophy, whereas most hydrolases and transporters are upregulated later, at the switch to necrotrophy. Our findings show that preinvasion perception of plant-derived signals substantially reprograms fungal gene expression and indicate previously unknown functions for particular fungal cell types.

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Lifestyle transitions in plant pathogenic Colletotrichum fungi deciphered by genome and transcriptome analyses

Most plant seeds are dispersed in a dry, mature state. If these seeds are non-dormant and the environmental conditions are favourable, they will pass through the complex process of germination. In this review, recent progress made with state-of-the-art techniques including genome-wide gene expression analyses that provided deeper insight into the early phase of seed germination, which includes imbibition and the subsequent plateau phase of water uptake in which metabolism is reactivated, is summarized. The physiological state of a seed is determined, at least in part, by the stored mRNAs that are translated upon imbibition. Very early upon imbibition massive transcriptome changes occur, which are regulated by ambient temperature, light conditions, and plant hormones. The hormones abscisic acid and gibberellins play a major role in regulating early seed germination. The early germination phase of Arabidopsis thaliana culminates in testa rupture, which is followed by the late germination phase and endosperm rupture. An integrated view on the early phase of seed germination is provided and it is shown that it is characterized by dynamic biomechanical changes together with very early alterations in transcript, protein, and hormone levels that set the stage for the later events. Early seed germination thereby contributes to seed and seedling performance important for plant establishment in the natural and agricultural ecosystem.

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First off the mark: early seed germination

It was established that total proteolytic activity in etiolated wheat seedlings changes in ontogenesis in cycles: peaks of proteolytic activity correspond to the 3rd, 5th, and 8th days of seedling growth, respectively. The maximum of proteolytic activity preceded the maximum of nuclease activity, which may be due to activation of nucleases by proteolytic enzymes. According to inhibitory analysis the cysteine and serine proteases play the main role in apoptosis in wheat coleoptiles. Growing of seedlings in the presence of ethrel stimulated apoptosis in the coleoptile, and it increased (almost 6-fold) the proteolytic activity in its cells. On the other hand, the antioxidant ionol (BHT) suppressed the induction of proteases, particularly at the second stage of coleoptile development, and it slowed down the increase in the nuclease activity after 6th day of the seedling life. It is suggested that phytohormones and antioxidants participate in regulation of apoptosis in the ageing coleoptile, directly or indirectly effecting the proteolytic apparatus in the coleoptile cells.

Effect of ethylene producer ethrel and antioxidant ionol (BHT) on the proteolytic apparatus in coleoptiles of wheat seedlings during apoptosis.

The paper revises data on the identification of peptidases groups involved in the growth of fungi and inhibitors of these peptidases. The available data on the diversity, significance, representation, and characteristics of proteolytic enzymes in representatives of the Aspergillus, Penicillium, Trichoderma, and Alternaria genera are considered. It was concluded that serine, metal, and glutamine peptidases are necessary for the growth of fungi. Therefore, these enzymes are considered as promising targets for peptidase inhibitors, which can serve as a rationale for the search for such inhibitors and the development of new biocidal agents on their basis for protecting art objects from biodestructors.

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Fungal Proteolytic Enzymes and Their Inhibitors as Perspective Biocides with Antifungal Action

awarding the Nobel Prize in Chemistry for 2004 attracted much attention of journalists. Headlines “kiss of death”, “the black label”, and “death label” clearly and literally underline the scientific problem that has been recognized by this award. As indicated in a press release of the Swedish Royal Academy of Sciences, the winners of the 2004 prize have provided scientific background for under standing the molecular basis of the mechanism of selec tive degradation of proteins. Two Israeli scientists Aaron Ciechanover and Avram Hershko from Technion Institute of Technology (Haifa) and American scientist Irvin Rose from University of California (Irvine, CA) discovered one of the most important processes occurring in eukaryotic cells, ATP dependent ubiquitin mediated protein cleav age [1 10]. This process consists of two steps. The first step includes elucidation and labeling of proteins, which should be degraded. The second step represents degrada tion of the targeted proteins catalyzed by a large cytosolic protein complex named the proteasome by Goldberg (another distinguished expert in this field) and his col leagues [11]. The ubiquitin–proteasome system provides “coexistence” between intracellular proteins and a non lysosomal proteolytic system, which can potentially degrade any protein in the cell. At the current stage of our knowledge, there is the following outline of the process of ubiquitin mediated proteolysis. Nature developed a highly specialized ubiqui tin conjugating system for identification and labeling of proteins that should be degraded by cells. Special degra dation signals recognized by this system may include pri mary structure motifs (N terminal amino acid residues), secondary post translational protein modifications (e.g., phosphorylation), and association with some additional proteins such as viral oncoproteins and molecular chap erones. The protein conjugating system is functionally and spatially proteasome independent. Proteins identi fied by the cell as the targets for proteolysis are labeled by covalent attachment of ubiquitin, a small and highly sta ble protein that consists of 76 amino acid residues. Biochemistry (Moscow), Vol. 70, No. 3, 2005, pp. 377 378. Translated from Biokhimiya, Vol. 70, No. 3, 2005, pp. 459 460. Original Russian Text Copyright © 2005 by Dunaevsky, Belozersky.

Nobel Prize in Chemistry 2004. The mechanism of ATP-dependent degradation of proteins involving ubiquitin

The activities of secreted and mycelial inhibitors of proteolytic enzymes from fungi of the order Hypocreales have been investigated. Inhibitors of bromelain, papain, and trypsin of low molecular mass (about 1 kDa) and a subtilisin proteinaceous inhibitor with molecular mass of 45 kDa were revealed in the culture liquid of the fungus Tolypocladium cylindrosporum. The subtilisin inhibitor from T. cylindrosporum has antibiotic properties, significantly decreased the activity of purified bacterial enzymes, and prevented the growth of the bacterium Pseudomonas sp. Data suggesting the existence in fungi of the Hypocreales order of two pools of peptidase inhibitors have been obtained.

Some properties and possible biological role of peptidase inhibitors from the entomopathogenic fungus Tolypocladium cylindrosporum

A detailed analysis of the complexes of proline-specific peptidases (PSPs) in the midgut transcriptomes of the larvae of agricultural pests Tenebrio molitor and Tribolium castaneum and in the genome of T. castaneum is presented. Analysis of the T. castaneum genome revealed 13 PSP sequences from the clans of serine and metal-dependent peptidases, of which 11 sequences were also found in the gut transcriptomes of both tenebrionid species’ larvae. Studies of the localization of PSPs, evaluation of the expression level of their genes in gut transcriptomes, and prediction of the presence of signal peptides determining secretory pathways made it possible to propose a set of peptidases that can directly participate in the hydrolysis of food proteins in the larvae guts. The discovered digestive PSPs of tenebrionids in combination with the post-glutamine cleaving cysteine cathepsins of these insects effectively hydrolyzed gliadins, which are the natural food substrates of the studied pests. Based on the data obtained, a hypothetical scheme for the complete hydrolysis of immunogenic gliadin peptides by T. molitor and T. castaneum digestive peptidases was proposed. These results show promise regarding the development of a drug based on tenebrionid digestive enzymes for the enzymatic therapy of celiac disease and gluten intolerance.

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Mikhail A. Belozersky

Papers

Effect of ethylene producer ethrel and antioxidant ionol (BHT) on the proteolytic apparatus in coleoptiles of wheat seedlings during apoptosis.

Fungal Proteolytic Enzymes and Their Inhibitors as Perspective Biocides with Antifungal Action

Nobel Prize in Chemistry 2004. The mechanism of ATP-dependent degradation of proteins involving ubiquitin

Some properties and possible biological role of peptidase inhibitors from the entomopathogenic fungus Tolypocladium cylindrosporum

Complex of Proline-Specific Peptidases in the Genome and Gut Transcriptomes of Tenebrionidae Insects and Their Role in Gliadin Hydrolysis