Increased baculovirus susceptibility of armyworm larvae feeding on transgenic rice plants expressing an entomopoxvirus gene

Hukuhara, Takehiko; Hayakawa, Tetsuo; Wijonarko, Arman

doi:10.1038/15110

Cited by 25 publications

(7 citation statements)

References 24 publications

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“…A CBM33 single domain protein is strongly up-regulated as part of the stress response of Enterococcus faecalis [69]. There is also convincing evidence showing CBM33s to be essential for the infectivity of insect-larvae targeting viruses [70,71], which could be a consequence of CBM33 effects on insect chitin. It is conceivable that in some cases the CBM33s have a mere binding function.…”

Section: Enzymatic Degradation Of Cellulosementioning

confidence: 99%

Novel enzymes for the degradation of cellulose

Horn

Vaaje‐Kolstad

Westereng

et al. 2012

Biotechnol Biofuels

904

682

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The bulk terrestrial biomass resource in a future bio-economy will be lignocellulosic biomass, which is recalcitrant and challenging to process. Enzymatic conversion of polysaccharides in the lignocellulosic biomass will be a key technology in future biorefineries and this technology is currently the subject of intensive research. We describe recent developments in enzyme technology for conversion of cellulose, the most abundant, homogeneous and recalcitrant polysaccharide in lignocellulosic biomass. In particular, we focus on a recently discovered new type of enzymes currently classified as CBM33 and GH61 that catalyze oxidative cleavage of polysaccharides. These enzymes promote the efficiency of classical hydrolytic enzymes (cellulases) by acting on the surfaces of the insoluble substrate, where they introduce chain breaks in the polysaccharide chains, without the need of first “extracting” these chains from their crystalline matrix.

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Section: Enzymatic Degradation Of Cellulosementioning

confidence: 99%

Novel enzymes for the degradation of cellulose

Horn

Vaaje‐Kolstad

Westereng

et al. 2012

Biotechnol Biofuels

904

682

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“…Remarkably, in larval cofeeding experiments, spindles also enhance the insecticidal activity of unrelated oral pathogens such as baculovirus (8) and the Bacillus thuringiensis (Bt) toxin (9) by up to three orders of magnitude. This effect on virulence prompted their use as synergistic additives to common bioinsecticides, for instance by transgenic expression of spindles in plants to improve the effectiveness of baculovirus insecticides (10).…”

mentioning

confidence: 99%

Structural basis for the enhancement of virulence by viral spindles and their in vivo crystallization

Chiu

Hijnen

Bunker

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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The great benefits that chemical pesticides have brought to agriculture are partly offset by widespread environmental damage to nontarget species and threats to human health. Microbial bioinsecticides are considered safe and highly specific alternatives but generally lack potency. Spindles produced by insect poxviruses are crystals of the fusolin protein that considerably boost not only the virulence of these viruses but also, in cofeeding experiments, the insecticidal activity of unrelated pathogens. However, the mechanisms by which spindles assemble into ultra-stable crystals and enhance virulence are unknown. Here we describe the structure of viral spindles determined by X-ray microcrystallography from in vivo crystals purified from infected insects. We found that a C-terminal molecular arm of fusolin mediates the assembly of a globular domain, which has the hallmarks of lytic polysaccharide monooxygenases of chitinovorous bacteria. Explaining their unique stability, a 3D network of disulfide bonds between fusolin dimers covalently crosslinks the entire crystalline matrix of spindles. However, upon ingestion by a new host, removal of the molecular arm abolishes this stabilizing network leading to the dissolution of spindles. The released monooxygenase domain is then free to disrupt the chitinrich peritrophic matrix that protects insects against oral infections. The mode of action revealed here may guide the design of potent spindles as synergetic additives to bioinsecticides.ost entomopoxviruses (EV) produce two types of intracellular crystals. Virus-containing spheroids are the main infectious form of EV (1) and are functionally analogous to polyhedra of cypovirus (2) and baculovirus (3, 4). In contrast, the function of the second type of crystals is less clear. These crystals of the viral fusolin protein, called "spindles" because of their characteristic shape, assemble in the endoplasmic reticulum of infected cells and for some species also occur embedded within the crystalline lattice of spheroids (5). Purified spindles are not infectious but strongly enhance the infectivity of EV by a mechanism that involves disruption of the peritrophic matrix, a physical barrier that protects the midgut epithelium of insects against oral pathogens (6, 7). Remarkably, in larval cofeeding experiments, spindles also enhance the insecticidal activity of unrelated oral pathogens such as baculovirus (8) and the Bacillus thuringiensis (Bt) toxin (9) by up to three orders of magnitude. This effect on virulence prompted their use as synergistic additives to common bioinsecticides, for instance by transgenic expression of spindles in plants to improve the effectiveness of baculovirus insecticides (10).Fusolin proteins have a signal sequence that targets them to the endoplasmic reticulum, and the mature protein has a mass of 36-44 kDa. Some fusolins are glycosylated, and the glycosylation site of the fusolin produced by Anomala cuprea EV (ACEV) is required for full virulence (11). Sequence analysis shows that the N-terminal regio...

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“…In microbial control of insect pests, the combination of two viruses that interact by synergism may purposely be used to enhance the effect of a viral insecticide formulation. Hukuhara et al (1999) have suggested the use of a virus enhancing factor from PSEV as an additive of NPV insecticides. For the opposite purpose, that is to say, to protect useful insects from viral infections, the knowledge of multiple virus interactions should also be useful.…”

Section: Resultsmentioning

confidence: 99%

Enhanced infection of an entomopoxvirus in larvae of the armyworm, Pseudaletia separata (Lepidoptera: Noctuidae), by a granulovirus

Hukuhara

Wijonarko

Hosokawa

et al. 2003

Appl. Entomol. Zool.

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To determine the interaction of Pseudaletia unipuncta granulovirus and Pseudaletia separata entomopoxvirus, larvae of the armyworm, P. separata, were perorally administered graded doses of entomopoxvirus occlusion bodies, spheroids, in the presence or absence of granulovirus occlusion bodies, capsules. The presence of capsules in the inocula enhanced entomopoxvirus infection. In doubly infected larvae, the inclusion bodies and virions of the two viruses coexisted in the same fatbody but never occurred in the same cells. The granulovirus appeared to facilitate entomopoxvirus infection at the organismal level, although the two viruses interfered with each other at the cellular level.

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Increased baculovirus susceptibility of armyworm larvae feeding on transgenic rice plants expressing an entomopoxvirus gene

Cited by 25 publications

References 24 publications

Novel enzymes for the degradation of cellulose

Novel enzymes for the degradation of cellulose

Structural basis for the enhancement of virulence by viral spindles and their in vivo crystallization

Enhanced infection of an entomopoxvirus in larvae of the armyworm, Pseudaletia separata (Lepidoptera: Noctuidae), by a granulovirus

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