Stomatal regulation, leaf water relations, and leaf phenology are coordinated in tree species from the Sonoran Desert.

To cope with heat and water stress, evergreen and deciduous species from hot and arid deserts should adjust their stomatal conductance ( ) and leaf water potential (Ψ) regulation in response to changes in soil water availability, high temperatures, and vapour pressure deficits (VPDs). To test whether phenology induces changes in -Ψ coordination, we tested for associations between 14 leaf traits involved in leaf economics, hydraulics, and stomatal regulation, including minimum seasonal water potential (Ψ) and maximum ( ), turgor loss point (Ψ), osmotic potential (Ψ), leaf area (LA), and specific leaf area (SLA), across 12 tree species from the Sonoran Desert with contrasting phenology. We found that foliar phenology, leaf hydraulics, and leaf economic traits are coordinated across species and organized along the axis of physiological efficiency and safety in response to temperature and VPD.

Structural considerations and differences between leaf canals and secretory cavities in Asteraceae.

Secretory canals are distributed among seed plants, and their diversity is concentrated in many families of angiosperms, while other internal secretory structures such as secretory cavities have been identified only in Rutaceae, Myrtaceae, and Asteraceae. Identifying and recognizing these two types of secretory structures has been complicated, mainly due to their structural similarities. In this study, the ontogeny of canals and secretory cavities in two species of Asteraceae are described and compared, to understand the structural differences between them and allow the establishment of more appropriate homology hypotheses.

Protocol to analyse the structural composition by fluorescence microscopy and different conventional and fluorescence staining methods.

The protocol shows the effectiveness of using safranin-fast green stain for fluorescence microscopy. This staining technique has been used in conventional microscopy to perform anatomical characterizations of plants. However, this protocol describes the procedure for using samples stained with safranin-fast green in conjunction with fluorescence microscopy.

Ecological implications of stomatal density and stomatal index in the adult stage of Mimosa L. (Leguminosae, Caesalpinioideae).

Differences in stomatal density (SD) and stomatal index (SI) are associated with the conditions of the environment in which they are distributed. Mimosa species are important elements in different plant communities, yet knowledge of the ecological implications of its stomatal characteristics is scarce. For this reason, SD and SI were determined in seven Mimosa species from different environments in this study.

Tree species differ in plant economic spectrum traits in the tropical dry forest of Mexico.

In tropical dry forests, studies on wood anatomical traits have concentrated mainly on variations in vessel diameter and frequency. Recent research suggests that parenchyma and fibers also play an important role in water conduction and in xylem hydraulic safety. However, these relationships are not fully understood, and wood trait variation among different functional profiles as well as their variation under different water availability scenarios have been little studied.

Lignin Analysis by HPLC and FTIR: Spectra Deconvolution and S/G Ratio Determination.

Fourier transform infrared spectroscopy (FTIR) is a simple nondestructive technique that allows the user to obtain quick and accurate information about the structure of the constituents of wood. Spectra deconvolution is a computational technique, complementary to FTIR analysis, which improves the resolution of overlapped or unobserved bands in the raw spectra. High performance liquid chromatography (HPLC) is an analytical technique useful to determine the ratio of the lignin monomers obtained by the alkaline nitrobenzene oxidation method.

Combining exposed tree roots and UAV imagery to quantify land denudation in central Mexico.

Approximately 42 % of Mexico is affected by soil denudation resulting from moderate to severe sheet erosion and gullying processes. At Huasca de Ocampo (central Mexico), soil degradation has been linked to intense land use dating back to pre-Hispanic times as well as to unfavorable geological, geomorphic, and climatic conditions. Here, we quantify erosion rates with high precision at annual to multi-decadal timescales by combining, for the first time, dendrogeomorphic reconstructions and UAV-based remote sensing.

Cellulose in Secondary Xylem of Cactaceae: Crystalline Composition and Anatomical Distribution.

Cellulose is the main polymer that gives strength to the cell wall and is located in the primary and secondary cell walls of plants. In Cactaceae, there are no studies on the composition of cellulose. The objective of this work was to analyze the crystallinity composition and anatomical distribution of cellulose in Cactaceae vascular tissue.

Fluorescence Microscopy Methods for the Analysis and Characterization of Lignin.

Lignin is one of the most studied and analyzed materials due to its importance in cell structure and in lignocellulosic biomass. Because lignin exhibits autofluorescence, methods have been developed that allow it to be analyzed and characterized directly in plant tissue and in samples of lignocellulose fibers. Compared to destructive and costly analytical techniques, fluorescence microscopy presents suitable alternatives for the analysis of lignin autofluorescence.

The role of wood anatomical traits in the coexistence of oak species along an environmental gradient.

Oaks () are a dominant woody plant genus in the northern hemisphere, which occupy a wide range of habitats and are ecologically diverse. We analysed the wood anatomical traits, the variables derived and the relative hydraulic conductivity of 21 oak species to identify their performance according to abiotic factors, leaf phenological patterns and phylogenetic restrictions by analysing the interspecific variation along an environmental gradient. First, we determine the causes of anatomical trait variation in the oaks, analysing the functional trade-offs related to distribution along the environmental gradient.

Distribution and Chemical Composition of Lignin in Secondary Xylem of Cactaceae.

Cactaceae family has heterogeneity in the accumulation of lignocellulose due to the diversity of shapes and anatomy of the wood. Most studies focus on fibrous and dimorphic species; but the non-fibrous species are poorly studied. The aims of this work were to analyze the syringyl/guaiacyl ratio of lignin and its distribution in secondary xylem, especially in non-fibrous species.

Leaf water relations reflect canopy phenology rather than leaf life span in Sonoran Desert trees.

Plants from arid environments display covarying traits to survive or resist drought. Plant drought resistance and ability to survive long periods of low soil water availability should involve leaf phenology coordination with leaf and stem functional traits related to water status. This study tested correlations between phenology and functional traits involved in plant water status regulation in 10 Sonoran Desert tree species with contrasting phenology.

Functional anatomy and xylem cavitation resistance of three species of monocotyledons grown on flooded substrates.

There are few investigations that analyze the xylem functional anatomy of monocotyledons, as the methods have been developed for woody plants. This study describes the root, rhizome and aerial stem xylem anatomy and functional anatomy of Canna indica, Cyperus papyrus and Phragmites communis grown on flooded substrates; and it aims to evaluate the relationship between the xylem anatomy and its cavitation resistance. To calculate the indexes of vulnerability, mesomorphy, collapse and relative hydraulic conductivity in the three organs mentioned, the diameter, number of vessels per mm , thickness of the walls and the length of the tracheal elements were recorded.

(Asparagaceae, Brodiaeoideae), a new genus segregated from the paraphyletic .

A new genus, , for the Brodiaeoideae, Asparagaceae family is here proposed. A taxonomic analysis based on morphology highlights its synapomorphies. The characters that distinguish are the absence of a pith in the gynophore and the presence of an entire stigma.

Active pollination drives selection for reduced pollen-ovule ratios.

Premise: Variation in pollen-ovule ratios is thought to reflect the degree of pollen transfer efficiency-the more efficient the process, the fewer pollen grains needed. Few studies have directly examined the relationship between pollen-ovule ratio and pollen transfer efficiency. For active pollination in the pollination brood mutualisms of yuccas and yucca moths, figs and fig wasps, senita and senita moths, and leafflowers and leafflower moths, pollinators purposefully collect pollen and place it directly on the stigmatic surface of conspecific flowers.

Differences in the Structural Chemical Composition of the Primary Xylem of Cactaceae: A Topochemical Perspective.

The xylem of Cactaceae is a complex system with different types of cells whose main function is to conduct and store water, mostly during the development of primary xylem, which has vessel elements and wide-band tracheids. The anatomy of primary xylem of Cactaceae has been widely studied, but little is known about its chemical composition. The aim of this study was to determine the structural chemical composition of the primary xylem of Cactaceae and to compare it with the anatomy in the group.

Variability and composition of calcium oxalate crystals in embryos-seedlings-adult plants of the globose cacti Mammillaria uncinata.

The morphology and elemental composition of crystals in embryos, seedlings and adult plants of the globose cacti Mammillaria uncinata were studied. Samples of mature fruits and adult plants were collected. To obtain embryos and seedlings, seeds from mature fruits were germinated under laboratory conditions.

Structural Characterization of Lignin in Four Cacti Wood: Implications of Lignification in the Growth Form and Succulence.

Wood lignin composition strongly depends on anatomical features and it has been used as a marker for characterizing major plant groups. Wood heterogeneity in Cactaceae is involved in evolutionary and adaptive processes within this group; moreover, it is highly correlated to the species growth form. Here we studied the lignin structure from different types of woods in four Cactaceae species with different stem morphologies (, tree/fibrous wood; and , tree/succulent fibrous wood; , cylindrical stem/dimorphic wood) in order to determine their relationship with the wood anatomy in an evolutionary-adaptive context.

Incorporating fossils into the Pinaceae tree of life.

Premise Of The Study: Pinaceae have a rich but enigmatic early fossil record, much of which is represented by permineralized seed cones. Our incomplete knowledge of morphology and anatomy in living and extinct species poses an important barrier to understanding their phylogenetic relationships and timing of diversification.

Methods: We expanded a morphology matrix to 46 fossil and 31 extant Pinaceae species, mainly adding characters from stem and leaf anatomy and seed cones.

Chemical Composition of Cacti Wood and Comparison with the Wood of Other Taxonomic Groups.

The aims of this study were to determine the wood chemical composition of 25 species of Cactaceae and to relate the composition to their anatomical diversity. The hypothesis was that wood chemical components differ in relationship to their wood features. The results showed significant differences in wood chemical compounds across species and genera (P < 0.

Species delimitation in the Stenocereus griseus (Cactaceae) species complex reveals a new species, S. huastecorum.

The Stenocereus griseus species complex (SGSC) has long been considered taxonomically challenging because the number of taxa belonging to the complex and their geographical boundaries remain poorly understood. Bayesian clustering and genetic distance-based methods were used based on nine microsatellite loci in 377 individuals of three main putative species of the complex. The resulting genetic clusters were assessed for ecological niche divergence and areolar morphology, particularly spination patterns.