The Cost of Self-Defense: Browsing Effects in the Rare Plant Species .

Coevolution between plants and their animal predators has led to diverse defensive adaptations. Multiple theories of defense propose that there are resource allocation costs associated with producing chemical defenses. One leading hypothesis, optimal defense theory (ODT), suggests that natural selection will result in the allocation of resources to defenses that optimize the cost-to-benefit ratio between defense and other functional processes.

Chemical Composition of Essential Oils from Natural Populations of Collected at Different Altitudes: Antibacterial, Mosquito Repellent, and Larvicidal Effects.

The current study aimed to evaluate the presence of chemical variations in essential oils (EOs) extracted from growing at different altitudes and to reveal their antibacterial, mosquito larvicidal, and repellent activity. The gas chromatographic-mass spectrometric analysis of EOs revealed that the major compounds were capillene (9.6-31.

Agrobacterium-Mediated Genetic Transformation of (Dunal) with A Genes and Its Antioxidant Potential.

In ancient times, Dunal was used as a therapeutic plant for the treatment of several diseases. This report aims to examine the effect of -mediated transformation of with the gene to enhance secondary metabolite production, antioxidant activity, and anticancer activity of transformed tissues. Before transgenic plant production, the authors designed an efficient methodology for transformation.

Phylogenomics reveals patterns of ancient hybridization and differential diversification that contribute to phylogenetic conflict in willows, poplars, and close relatives.

Despite the economic, ecological, and scientific importance of the genera Salix L. (willows) and Populus L. (poplars, cottonwoods, and aspens) Salicaceae, we know little about the sources of differences in species diversity between the genera and of the phylogenetic conflict that often confounds estimating phylogenetic trees.

The chemical biogeography of a widespread aromatic plant species shows both spatial and temporal variation.

Plants produce a wide variety of secondary metabolites, but intraspecific variation in space and time can alter the ecological interactions these compounds mediate. The aim of this work was to document the spatial and temporal chemical biogeography of . I collected leaves from 1587 individuals from 86 populations from Colorado to Manitoba, extracted and analyzed their terpenes with gas chromatography, mapped monoterpene chemotypes, and analyzed chemical variation with principal component analysis.

Repeated turnovers keep sex chromosomes young in willows.

Background: Salicaceae species have diverse sex determination systems and frequent sex chromosome turnovers. However, compared with poplars, the diversity of sex determination in willows is poorly understood, and little is known about the evolutionary forces driving their turnover. Here, we characterized the sex determination in two Salix species, S.

Genetic mapping of sexually dimorphic volatile and non-volatile floral secondary chemistry of a dioecious willow.

Secondary chemistry often differs between sexes in dioecious plant species, a pattern attributed to its possible role in the evolution and/or maintenance of dioecy. We used GC-MS to measure floral volatiles emitted from, and LC-MS to quantitate non-volatile secondary compounds contained in, female and male Salix purpurea willow catkins from an F2 family. Using the abundance of these chemicals, we then performed quantitative trait locus (QTL) mapping to locate them on the genome, identified biosynthetic candidate genes in the QTL intervals, and examined expression patterns of candidate genes using RNA-seq.

Population-specific responses of floral volatiles to abiotic factors in changing environments.

Premise: Shifts in abiotic factors can affect many plant traits, including floral volatiles. This study examined the response of floral volatiles to water availability and whether phenotypic plasticity to water availability differs among populations. It also investigated genetic differentiation in floral volatiles, determined the effect of temperature on phenotypic plasticity to water availability, and assessed temporal variation in floral scent emission between day and evening, since pollinator visitation differs at those times.

Combined drought and bark beetle attacks deplete non-structural carbohydrates and promote death of mature pine trees.

How carbohydrate reserves in conifers respond to drought and bark beetle attacks are poorly understood. We investigated changes in carbohydrate reserves and carbon-dependent diterpene defences in ponderosa pine trees that were experimentally subjected to two levels of drought stress (via root trenching) and two types of biotic challenge treatments (pheromone-induced bark beetle attacks or inoculations with crushed beetles that include beetle-associated fungi) for two consecutive years. Our results showed that trenching did not influence carbohydrates, whereas both biotic challenges reduced amounts of starch and sugars of trees.

Growth-defense trade-offs shape population genetic composition in an iconic forest tree species.

All organisms experience fundamental conflicts between divergent metabolic processes. In plants, a pivotal conflict occurs between allocation to growth, which accelerates resource acquisition, and to defense, which protects existing tissue against herbivory. Trade-offs between growth and defense traits are not universally observed, and a central prediction of plant evolutionary ecology is that context-dependence of these trade-offs contributes to the maintenance of intraspecific variation in defense [Züst and Agrawal, , 68, 513-534 (2017)].

Characterization of floral insect community and activity of three native bees.

(black willow) is a widespread tree that hosts many species of polylectic hymenopterans and oligolectic bees of the genus . The early flowering of makes it an important nutritive resource for arthropods emerging from hibernation. However, since is dioecious, not all insect visits will lead to successful pollination.

Sex determination through X-Y heterogamety in Salix nigra.

The development of non-recombining sex chromosomes has radical effects on the evolution of discrete sexes and sexual dimorphism. Although dioecy is rare in plants, sex chromosomes have evolved repeatedly throughout the diversification of angiosperms, and many of these sex chromosomes are relatively young compared to those found in vertebrates. In this study, we designed and used a sequence capture array to identify a novel sex-linked region (SLR) in Salix nigra, a basal species in the willow clade, and demonstrated that this species has XY heterogamety.

Evolutionary history and ecology shape the diversity and abundance of phytochemical arsenals across monkeyflowers.

We examine the extent to which phylogenetic effects and ecology are associated with macroevolutionary patterns of phytochemical defence production across the Mimulus phylogeny. We grew plants from 21 species representing the five major sections of the Mimulus phylogeny in a common garden to assess how the arsenals (NMDS groupings) and abundances (concentrations) of a phytochemical defence, phenylpropanoid glycosides (PPGs), vary across the phylogeny. Very few PPGs are widespread across the genus, but many are common to multiple sections of the genus.

Trait plasticity and trade-offs shape intra-specific variation in competitive response in a foundation tree species.

The ability to tolerate neighboring plants (i.e. degree of competitive response) is a key determinant of plant success in high-competition environments.

Metagenomics Reveals Diet-Specific Specialization of Bacterial Communities in Fungus Gardens of Grass- and Dicot-Cutter Ants.

Leaf-cutter ants in the genus are dominant herbivores in the Neotropics. While most species of cut dicots to incorporate into their fungus gardens, some species specialize on grasses. Here we examine the bacterial community associated with the fungus gardens of grass- and dicot-cutter ants to examine how changes in substrate input affect the bacterial community.

A General Model to Explain Repeated Turnovers of Sex Determination in the Salicaceae.

Dioecy, the presence of separate sexes on distinct individuals, has evolved repeatedly in multiple plant lineages. However, the specific mechanisms by which sex systems evolve and their commonalities among plant species remain poorly understood. With both XY and ZW sex systems, the family Salicaceae provides a system to uncover the evolutionary forces driving sex chromosome turnovers.

Bacteria Contribute to Plant Secondary Compound Degradation in a Generalist Herbivore System.

Herbivores must overcome a variety of plant defenses, including coping with plant secondary compounds (PSCs). To help detoxify these defensive chemicals, several insect herbivores are known to harbor gut microbiota with the metabolic capacity to degrade PSCs. Leaf-cutter ants are generalist herbivores, obtaining sustenance from specialized fungus gardens that act as external digestive systems and which degrade the diverse collection of plants foraged by the ants.

Host plant genetic control of associated fungal and insect species in a hybrid cross.

Plants employ a diverse set of defense mechanisms to mediate interactions with insects and fungi. These relationships can leave lasting impacts on host plant genome structure such as rapid expansion of gene families through tandem duplication. These genomic signatures provide important clues about the complexities of plant/biotic stress interactions and evolution.

Pathways to sex determination in plants: how many roads lead to Rome?

The presence of thousands of independent origins of dioecy in angiosperms provides a unique opportunity to address the parallel evolution of the molecular pathways underlying unisexual flowers. Recent progress towards identifying sex determination genes has identified hormone response pathways, mainly associated with cytokinin and ethylene response pathways, as having been recruited multiple times independently to control unisexuality. Moreover, transcriptomics has begun to identify commonalities among intermediate sections of signal transduction pathways.

Sexual and genotypic variation in terpene quantitative and qualitative profiles in the dioecious shrub Baccharis salicifolia.

Terpenoids are secondary metabolites produced in most plant tissues and are often considered toxic or repellent to plant enemies. Previous work has typically reported on intra-specific variation in terpene profiles, but the effects of plant sex, an important axis of genetic variation, have been less studied for chemical defences in general, and terpenes in particular. In a prior study, we found strong genetic variation (but not sexual dimorphism) in terpene amounts in leaves of the dioecious shrub Baccharis salicifolia.

Phylogenomics of the genus Populus reveals extensive interspecific gene flow and balancing selection.

Phylogenetic analysis is complicated by interspecific gene flow and the presence of shared ancestral polymorphisms, particularly those maintained by balancing selection. In this study, we aimed to examine the prevalence of these factors during the diversification of Populus, a model tree genus in the Northern Hemisphere. We constructed phylogenetic trees of 29 Populus taxa using 80 individuals based on re-sequenced genomes.

Drought-Mediated Changes in Tree Physiological Processes Weaken Tree Defenses to Bark Beetle Attack.

Interactions between water stress and induced defenses and their role in tree mortality due to bark beetles are poorly understood. We performed a factorial experiment on 48 mature ponderosa pines (Pinus ponderosa) in northern Arizona over three years that manipulated a) tree water stress by cutting roots and removing snow; b) bark beetle attacks by using pheromone lures; and c) phloem exposure to biota vectored by bark beetles by inoculating with dead beetles. Tree responses included resin flow from stem wounds, phloem composition of mono- and sesqui-terpenes, xylem water potential, leaf gas exchange, and survival.

Author Correction: Drier Climatic Conditions Increase Withanolide Content of Withania coagulans Enhancing its Inhibitory Potential against Human Prostate Cancer Cells.

The original version of this article unfortunately contained a mistake in the image of Figure 1 and in Table 4. The corrected version of the figure and table is shown here.