Selection pressure by specialist and generalist insect herbivores leads to optimal constitutive plant defense. A mathematical model.

Brassicaceae plants have the glucosinolate-myrosinase defense system, jointly active against herbivory. However, constitutive glucosinolate (GLS) defense is observed to occur at levels that do not deter all insects from feeding. That prompts the question of why Brassicaceae plants have not evolved a higher constitutive defense.

Ontogeny of color development in two green-brown polymorphic grasshopper species.

Many insects, including several orthopterans, undergo dramatic changes in body coloration during ontogeny. This variation is particularly intriguing in gomphocerine grasshoppers, where the green and brown morphs appear to be genetically determined (Schielzeth & Dieker, 2020, , 20, 63; Winter et al., 2021, , 127, 66).

Transcriptome-based identification and functional characterization of iridoid synthase involved in monotropein biosynthesis in blueberry.

Blueberries ( spp.) are well known for their nutritional quality, and recent work has shown that spp. also produce iridoids, which are specialized metabolites with potent health-promoting benefits.

Antioxidant availability trades off with warning signals and toxin sequestration in the large milkweed bug ().

In some aposematic species the conspicuousness of an individual's warning signal and the concentration of its chemical defense are positively correlated. Several mechanisms have been proposed to explain this phenomenon, including resource allocation trade-offs where the same limiting resource is needed to produce both the warning signal and chemical defense. Here, the large milkweed bug (: Heteroptera, Lygaeinae) was used to test whether allocation of antioxidants, that can impart color, trade against their availability to prevent self-damage caused by toxin sequestration.

Towards evolutionary predictions: Current promises and challenges.

Evolution has traditionally been a historical and descriptive science, and predicting future evolutionary processes has long been considered impossible. However, evolutionary predictions are increasingly being developed and used in medicine, agriculture, biotechnology and conservation biology. Evolutionary predictions may be used for different purposes, such as to prepare for the future, to try and change the course of evolution or to determine how well we understand evolutionary processes.

Carnivorous Nepenthes x ventrata plants use a naphthoquinone as phytoanticipin against herbivory.

Carnivorous plants feed on animal prey, mainly insects, to get additional nutrients. This carnivorous syndrome is widely investigated and reported. In contrast, reports on herbivores feeding on carnivorous plants and related defenses of the plants under attack are rare.

microRNA390 modulates 's tolerance response to herbivory.

miR390 is a highly conserved miRNA in plant lineages known to function in growth and development processes, such as lateral root development, and in responses to salt and metal stress. In the ecological model species, , miR390's biological function remains unknown, which we explore here with a gain-of-function analysis with plants over-expressing (OE-) miR390 (Na-miR390) in glasshouse and natural environments. OEmiR390 plants showed normal developmental processes, including lateral root formation or reproductive output, in plants grown under standard conditions in the glasshouse.

Invasive earthworms reduce chemical defense and increase herbivory and pathogen infection in native trees.

Recent research shows that earthworms can alter defense traits of plants against herbivores and pathogens by affecting soil biochemistry. Yet, the effects of invasive earthworms on defense traits of native plants from previously earthworm-free ecosystems as well as the consequences for multitrophic interactions are virtually unknown.Here we use a combination of an observational study and a complementary experimental study to investigate the effects of invasive earthworms on leaf defense traits, herbivore damage and pathogen infection in two poplar tree species ( and ) native to North American boreal forests.

Two lathyrane diterpenoid stereoisomers containing an unusual -dimethylcyclopropane from the seeds of .

Two novel lathyrane-type diterpenoids, the factors L (1) and L (2), and their stereoisomer factor L (3) were obtained from seeds of . Both factors L and L possess an unprecedented -dimethylcyclopropane as structural feature. Also, the factor L is the first example of a lathyrane diterpenoid with an endocyclic 12()-double bond.

Context-dependent venom deployment and protein composition in two assassin bugs.

The Heteroptera are a diverse suborder of phytophagous, hematophagous, and zoophagous insects. The shift to zoophagy can be traced back to the transformation of salivary glands into venom glands, but the venom is used not only to kill and digest invertebrate prey but also as a defense strategy, mainly against vertebrates. In this study, we used an integrated transcriptomics and proteomics approach to compare the composition of venoms from the anterior main gland (AMG) and posterior main gland (PMG) of the reduviid bugs L.

Plants use identical inhibitors to protect their cell wall pectin against microbes and insects.

As fundamentally different as phytopathogenic microbes and herbivorous insects are, they enjoy plant-based diets. Hence, they encounter similar challenges to acquire nutrients. Both microbes and beetles possess polygalacturonases (PGs) that hydrolyze the plant cell wall polysaccharide pectin.

Trait-mediated indirect interactions: Moose browsing increases sawfly fecundity through plant-induced responses.

Induced responses in plants, initiated by herbivory, create potential for trait-mediated indirect interactions among herbivores. Responses to an initial herbivore may change a number of plant traits that subsequently alter ecological processes with additional herbivores. Although common, indirect interactions between taxonomically distant herbivores, such as mammals and insects, are less studied than between taxonomically related species (i.

The Bellerophon pipeline, improving de novo transcriptomes and removing chimeras.

Transcriptome quality control is an important step in RNA-Seq experiments. However, the quality of de novo assembled transcriptomes is difficult to assess, due to the lack of reference genome to compare the assembly to. We developed a method to assess and improve the quality of de novo assembled transcriptomes by focusing on the removal of chimeric sequences.

Adaptation of flea beetles to Brassicaceae: host plant associations and geographic distribution of Latreille and Chevrolat (Coleoptera, Chrysomelidae).

The cosmopolitan flea beetle genera and (Galerucinae, Alticini) are mainly associated with host plants in the family Brassicaceae and include economically important pests of crucifer crops. In this review, the host plant associations and geographical distributions of known species in these genera are summarised from the literature, and their proposed phylogenetic relationships to other Alticini analysed from published molecular phylogenetic studies of Galerucinae. Almost all species are specialised on Brassicaceae and related plant families in the order Brassicales, whereas species are associated with host plants in approximately 24 different plant families, and 50% are specialised to feed on Brassicaceae.

Symbiont-mediated chemical defense in the invasive ladybird .

The volatile alkylpyrazines methyl- and methoxypyrazines (MPs) present in the reflex bleeds of coccinellid beetles such as the harlequin ladybird beetle are important semiochemicals that function in antipredatory defense behavior. Pyrazines have also been coadapted from a primarily defensive role into pheromones that function in intraspecific communication, attraction, and aggregation behavior. However, the biosynthesis of MPs in ladybird beetles is poorly understood.

A subset of chemosensory genes differs between two populations of a specialized leaf beetle after host plant shift.

Due to its fundamental role in shaping host selection behavior, we have analyzed the chemosensory repertoire of . This specialized leaf beetle evolved distinct populations which shifted from the ancestral host plant, willow ( sp., Salicaceae), to birch (, Betulaceae).

Immunological larval polyphenism in the map butterfly reveals the photoperiodic modulation of immunity.

The bivoltine European map butterfly () displays seasonal polyphenism characterized by the formation of two remarkably distinct dorsal wing phenotypes: The spring generation () is predominantly orange with black spots and develops from diapause pupae, whereas the summer generation () has black, white, and orange bands and develops from subitaneous pupae. The choice between spring or summer imagoes is regulated by the photoperiod during larval and prepupal development, but polyphenism in the larvae has not been investigated before. Recently, it has been found that the prepupae of display differences in immunity-related gene expression, so we tested whether larvae destined to become spring (short-day) or summer (long-day) morphs also display differences in innate immunity.

Species-specific regulation of herbivory-induced defoliation tolerance is associated with jasmonate inducibility.

Induced changes in root carbohydrate pools are commonly assumed to determine plant defoliation tolerance to herbivores. However, the regulation and species specificity of these two traits are not well understood. We determined herbivory-induced changes in root carbohydrates and defoliation tolerance in seven different solanaceous plant species and correlated the induced changes in root carbohydrates and defoliation tolerance with jasmonate inducibility.

Evidence for GABA-Induced Systemic GABA Accumulation in upon Wounding.

The non-proteinogenic amino acid γ-aminobutyric acid (GABA) is present in all plant species analyzed so far. Its synthesis is stimulated by either acidic conditions occurring after tissue disruption or higher cytosolic calcium level. In mammals, GABA acts as inhibitory neurotransmitter but its function in plants is still not well understood.

Bacterial Community and PHB-Accumulating Bacteria Associated with the Wall and Specialized Niches of the Hindgut of the Forest Cockchafer ().

A characterization of the bacterial community of the hindgut wall of two larval and the adult stages of the forest cockchafer () was carried out using amplicon sequencing of the 16S rRNA gene fragment. We found that, in second-instar larvae, Caulobacteraceae and Pseudomonadaceae showed the highest relative abundances, while in third-instar larvae, the dominant families were Porphyromonadaceae and Bacteroidales-related. In adults, an increase of the relative abundance of Bacteroidetes, Proteobacteria (γ- and δ- classes) and the family Enterococcaceae (Firmicutes) was observed.

Corrigendum: Optimization of Agroinfiltration in Provides a New Tool for Studying the Salivary Protein Functions in the Pea Aphid Complex.

[This corrects the article on p. 1171 in vol. 7, PMID: 27555856.

Modulation of Legume Defense Signaling Pathways by Native and Non-native Pea Aphid Clones.

The pea aphid () is a complex of at least 15 genetically different host races that are native to specific legume plants, but can all develop on the universal host plant . Despite much research, it is still unclear why pea aphid host races (biotypes) are able to colonize their native hosts while other host races are not. All aphids penetrate the plant and salivate into plant cells when they test plant suitability.

Laser Microdissection and Spatiotemporal Pinoresinol-Lariciresinol Reductase Gene Expression Assign the Cell Layer-Specific Accumulation of Secoisolariciresinol Diglucoside in Flaxseed Coats.

The concentration of secoisolariciresinol diglucoside (SDG) found in flaxseed ( L.) is higher than that found in any other plant. It exists in flaxseed coats as an SDG-3-hydroxy-3-methylglutaric acid oligomer complex.