NMR Fingerprints of Formyl Phloroglucinol Meroterpenoids and Their Application to the Investigation of subsp. .

NMR fingerprints provide powerful tools to identify natural products in complex mixtures. Principal component analysis and machine learning using H and C NMR data, alongside structural information from 180 published formyl phloroglucinols, have generated diagnostic NMR fingerprints to categorize subclasses within this group. This resulted in the reassignment of 167 NMR chemical shifts ascribed to 44 compounds.

New approaches to tannin analysis of leaves can be used to explain in vitro biological activities associated with herbivore defence.

Although tannins have been an important focus of studies of plant-animal interactions, traditional tannin analyses cannot differentiate between the diversity of structures present in plants. This has limited our understanding of how different mixtures of these widespread secondary metabolites contribute to variation in biological activity. We used UPLC-MS/MS to determine the concentration and broad composition of tannins and polyphenols in 628 eucalypt (Eucalyptus, Corymbia and Angophora) samples, and related these to three in vitro functional measures believed to influence herbivore defence: protein precipitation capacity, oxidative activity at high pH and capacity to reduce in vitro nitrogen (N) digestibility.

Differential metabolic specialization of foliar oil glands in Eucalyptus brevistylis Brooker (Myrtaceae).

Trees and shrubs from the genus Eucalyptus are characterized by the presence of numerous foliar oil glands that generally house mono- and sesquiterpenes. In some species, glands are also known to house substantial quantities of unrelated secondary metabolites such as volatile, aromatic β-triketones. It is not known if these compounds are co-housed with terpenes or if they are produced in distinct, metabolically specialized glands.

Genus-wide variation in foliar polyphenolics in eucalypts.

Many studies quantify total phenolics or total tannins, but understanding the ecological role of polyphenolic secondary metabolites requires at least an understanding of the diversity of phenolic groups present. We used UPLC-MS/MS to measure concentrations of different polyphenol groups - including the four most common tannin groups, the three most common flavonoid groups, and quinic acid derivatives - in foliage from 628 eucalypts from the genera Eucalyptus, Angophora and Corymbia. We also tested for phylogenetic signal in each of the phenolic groups.

Apparent Overinvestment in Leaf Venation Relaxes Leaf Morphological Constraints on Photosynthesis in Arid Habitats.

Leaf veins supply the mesophyll with water that evaporates when stomata are open to allow CO uptake for photosynthesis. Theoretical analyses suggest that water is optimally distributed in the mesophyll when the lateral distance between veins (d) is equal to the distance from these veins to the epidermis (d), expressed as d:d ≈ 1. Although this theory is supported by observations of many derived angiosperms, we hypothesize that plants in arid environments may reduce d:d below unity owing to climate-specific functional adaptations of increased leaf thickness and increased vein density.

High density, genome-wide markers and intra-specific replication yield an unprecedented phylogenetic reconstruction of a globally significant, speciose lineage of Eucalyptus.

We used genome-wide markers and an unprecedented scale of sampling to construct a phylogeny for a globally significant Eucalyptus lineage that has been impacted by hybridisation, recent radiation and morphological convergence. Our approach, using 3109 DArT markers distributed throughout the genome and 540 samples covering 185 terminal taxa in sections Maidenaria, Exsertaria, Latoangulatae and related smaller sections, with multiple geographically widespread samples per terminal taxon, produced a phylogeny that largely matched the morphological treatment of sections, though sections Exsertaria and Latoangulatae were polyphyletic. At lower levels there were numerous inconsistencies between the morphological treatment and the molecular phylogeny, and taxa within the three main sections were generally not monophyletic at the series (at least 62% polyphyly) or species (at least 52% polyphyly) level.

Correction: Foliar Essential Oil Glands of Eucalyptus Subgenus Eucalyptus (Myrtaceae) Are a Rich Source of Flavonoids and Related Non-Volatile Constituents.

[This corrects the article DOI: 10.1371/journal.pone.

Foliar Essential Oil Glands of Eucalyptus Subgenus Eucalyptus (Myrtaceae) Are a Rich Source of Flavonoids and Related Non-Volatile Constituents.

The sub-dermal secretory cavities (glands) embedded within the leaves of Eucalyptus (Myrtaceae) were once thought to be the exclusive repositories of monoterpene and sesquiterpene oils. Recent research has debunked this theory and shown that abundant non-volatile compounds also occur within foliar glands. In particular, glands of four species in subgenus Eucalyptus contain the biologically active flavanone pinocembrin.

Patterns of Reproductive Isolation in Eucalyptus-A Phylogenetic Perspective.

We assess phylogenetic patterns of hybridization in the speciose, ecologically and economically important genus Eucalyptus, in order to better understand the evolution of reproductive isolation. Eucalyptus globulus pollen was applied to 99 eucalypt species, mainly from the large commercially important subgenus, Symphyomyrtus. In the 64 species that produce seeds, hybrid compatibility was assessed at two stages, hybrid-production (at approximately 1 month) and hybrid-survival (at 9 months), and compared with phylogenies based on 8,350 genome-wide DArT (diversity arrays technology) markers.

Novel distances for dollo data.

We investigate distances on binary (presence/absence) data in the context of a Dollo process, where a trait can only arise once on a phylogenetic tree but may be lost many times. We introduce a novel distance, the Additive Dollo Distance (ADD), that applies to data generated under a Dollo model and show that it has some useful theoretical properties including an intriguing link to the LogDet/paralinear distance. Simulations of Dollo data are used to compare a number of binary distances including ADD, LogDet, a restriction-site-based distance, and some simple, but to our knowledge previously unstudied, variations on common binary distances.

Population genetic analysis and phylogeny reconstruction in Eucalyptus (Myrtaceae) using high-throughput, genome-wide genotyping.

A set of over 8000 Diversity Arrays Technology (DArT) markers was tested for its utility in high-resolution population and phylogenetic studies across a range of Eucalyptus taxa. Small-scale population studies of Eucalyptus camaldulensis, Eucalyptus cladocalyx, Eucalyptus globulus, Eucalyptus grandis, Eucalyptus nitens, Eucalyptus pilularis and Eucalyptus urophylla demonstrated the potential of genome-wide genotyping with DArT markers to differentiate species, to identify interspecific hybrids and to resolve biogeographic disjunctions within species. The population genetic studies resolved geographically partitioned clusters in E.

A metabolomic approach to identifying chemical mediators of mammal-plant interactions.

Different folivorous marsupials select their food from different subgenera of Eucalyptus, but the choices cannot be explained by known antifeedants, such as formylated phloroglucinol compounds or tannins, or by nutritional quality. Eucalypts contain a wide variety of plant secondary metabolites so it is difficult to use traditional methods to identify the chemicals that determine food selection. Therefore, we used a metabolomic approach in which we employed (1)H nuclear magnetic resonance spectroscopy to compare chemical structures of representatives from the two subgenera and to identify chemicals that consistently differ between them.

Growth in two common gardens reveals species by environment interaction in carbon isotope discrimination of Eucalyptus.

One-year-old sun leaves of 60 species of Eucalyptus were collected in August 2005 at an arboretum in South Australia with a mean annual rainfall of 427 mm, and 14 of the same species were sampled at an arboretum in Western Australia with a mean annual rainfall of 216 mm. We determined the genetic and phenotypic variation in carbon isotope composition (delta13C), specific leaf area (SLA) and nitrogen content per unit area of the species at each site. There were very significant (P < 0.

Annual rainfall does not directly determine the carbon isotope ratio of leaves of Eucalyptus species.

Leaf carbon isotope discrimination (delta13C) was widely considered to directly reflect the rainfall environment in which the leaf developed, but recent observations have queried this. The relationship between delta13C and rainfall was explored in Eucalyptus species growing along a rainfall gradient in Australia. The leaves of 43 species of Eucalyptus and the closely related Corymbia species produced in 2003 were sampled in September 2004 at 50 sites and grouped into 15 locations along a rainfall gradient in southwest Western Australia.

Leaf and wood carbon isotope ratios, specific leaf areas and wood growth of Eucalyptus species across a rainfall gradient in Australia.

Leaves and samples of recent wood of Eucalyptus species were collected along a rainfall gradient parallel to the coast of Western Australia between Perth in the north and Walpole in the south and along a southwest to northeast transect from Walpole in southwestern Australia, to near Mount Olga in central Australia. The collection included 65 species of Eucalyptus sampled at 73 sites and many of the species were collected at several sites along the rainfall gradient. Specific leaf area (SLA) and isotopic ratio of 13C to 12C (delta 13C) of leaves that grew in 2002, and tree ring growth and delta 13C of individual cell layers of the wood were measured.