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Pherosphaera fitzgeraldii , the Dwarf Mountain Pine, is a critically endangered conifer restricted to cliff ledges within waterfall spray zones in the Greater Blue Mountains Area of New South Wales, Australia. This species is under threat from pollution, invasive weeds, and limited recruitment, which are contributing to its declining population. Using a comprehensive conservation genomic approach, we assessed the population health of P. fitzgeraldii and developed strategic recommendations for its management. Genomic analysis of P. fitzgeraldii revealed the presence of two distinct genetic groups despite the limited distribution of the species. This genetic structure aligns with prevailing wind currents, indicating potential restrictions to pollen or seed exchange between subpopulations. Furthermore, limited gene flow was observed even among nearby subpopulations, emphasizing the risk of increased genetic differentiation due to ongoing isolation. Clonality is widespread in some subpopulations, and all subpopulations displayed signs of inbreeding and genetic depletion despite subdioecy, indicative of historical constraints on gene flow and small population sizes. We offer genomic-based recommendations for prioritizing conservation sites, enhancing genetic diversity in ex situ collections, and guiding future management. Further studies to uncover the sex determination mechanism of P. fitzgeraldii could help maintain balanced sex ratios in ex situ collections and support future genetic rescue efforts. This study underscores the value of genomics in informing protection and recovery of unique threatened species. [ABSTRACT FROM AUTHOR]

Chamaecyparis obtusa var. formosana is significant as a precious and endemic plant in Taiwan. The trunk, renowned for its excellent texture and color, is ideal for construction materials and furniture. Moreover, the entire plant is rich in aroma, which can be made into essential oils, fragrances, and a series of related products. Volatile terpenoids are the major compounds in the composition of essential oils, many of which can only be found in C. obtusa var. formosana. In this study, we successfully identified 12 volatile terpene synthases from C. obtusa var. formosan a. Most of the selected TPSs displayed the ability to catalyze precursors into cyclic terpenoids, except for CovfTPS8, which also exhibited the capability to react with FPP and GPP. CovfTPS10 is particularly noteworthy for its multi-product characteristics and the ability to synthesize acoradiene. Moreover, it produces a novel compound, cis-isoduacene. Through the investigation of these volatile-terpenoid synthases, we can gain a better understanding of the cyclization process for terpenoids. • Sesquiterpene synthases for 1,6 cyclization, 1,10 cyclization, and 1,11 cyclization sesquiterpene were found in C. obtusa var. formosan a. [ABSTRACT FROM AUTHOR]

A total of 518 endophytic fungal taxa (excluding 105 taxa identified beyond the level of genus and Mycelia sterilia) from 370 genera belonging to 188 families (including forty six isolates of uncertain taxonomic positions), were isolated from seventeen different Cycads. The results revealed that, although members of Ascomycota were dominant, the presence of Basidiomycota, Mucoromycota, Chytridiomycota, Olpidiomycota and Zoopagomycota couldn't be ruled out. The endophytic fungi associated with Cycadales have been reported to exist in different primary lifestyles viz. plant_pathogens (86 genera), wood_saprotroph (78 genera), litter_saprotroph (44 genera), soil_saprotroph (41 genera), animal_parasite (24 genera), unspecified_saprotroph (20 genera), mycoparasite (13 genera), nectar/tap_saprotroph (11 genera), na and lichenized (08 genera each), ectomycorrhizal (07 genera), dung_saprotroph (06 genera), foliar_endophyte and arbuscular_mycorrhizal (05 genera each), epiphyte (04 genera), algal_parasite (03 genera), pollen_saprotroph and root_endophyte (02 genera each), lichen_parasite, unspecified_pathotroph, sooty_mold (01 genera each) (excluding 105 taxa which were identified either up to class, order and family level or are treated as incertae sedis, and Mycelia sterilia) and possibly produce several toxic compounds. In a nut shell, the presence of fungal endophytes of different life histories, in a Cycad's endobiome, their long evolutionary history of association with the leaf, and capability of producing several mycotoxins could possibly mediate herbivory, and these specific fungal endophytes could be identified as candidates for future functional study. • Endophytic fungi in Cycads show diverse lifestyles, viz. pathogens, saprotrophs, parasites, mycorrhizal, and lichenized forms. • Endophytic fungi, leaf traits, and secondary metabolites may contribute to the anti-herbivory effect of Cycads. • They have a long evolutionary history with Cycads and may produce mycotoxins, potentially influencing herbivory. • Certain fungal endophytes from Cycads could be key candidates for future functional studies in mediating herbivory. • Cycads can be used as avenue and fencing plants. [ABSTRACT FROM AUTHOR]

• The stem CH 4 emissions in wetlands are significantly higher than in uplands. • The stem CH 4 emissions of angiosperm are higher than gymnosperm trees. • The stem CH 4 emissions in coastal wetlands are less than in inland wetlands. • The source of stem CH 4 emissions in wetlands is from the soil. Growing evidence suggests that methane (CH 4) emissions from tree stems are a potentially significant atmospheric source. However, a comprehensive global assessment of the general pattern and the controlling factors of stem CH 4 emissions is still unavailable. Here, we present a global data-synthesis of 1081 observations from 62 studies to explore the patterns of stem CH 4 emission rate in upland and wetland ecosystems and their controlling factors. The global average stem CH 4 emission rate in uplands was 2.04 ± 0.61 nmol m −2 s −1, which was significantly lower than in wetlands (87.08 ± 19.49 nmol m −2 s −1). Angiosperm stem CH 4 emission rates were significantly higher than gymnosperm in both upland and wetland ecosystems. Meanwhile, stem CH 4 emission rate in inland wetlands (101.78 ± 27.44 nmol m −2 s −1) was significantly higher than in coastal wetlands (56.21 ± 19.23 nmol m −2 s −1). In both wetland and upland ecosystems, stem CH 4 emission rate decreased with increasing sampling height, but increased as soil CH 4 emission rate increased. However, the relationship between stem CH 4 emissions and soil CH 4 fluxes was much weaker for uplands, but very strong for wetlands. In wetlands, stem CH 4 emission rate was also regulated by plant properties, as it was negatively correlated with wood specific density, but positively correlated with stem lenticel density. In uplands, tree diameter negatively affected stem CH 4 emission rate. Overall, our results shed light on the magnitude and controlling factors of stem CH 4 emissions in upland and wetland ecosystems and could facilitate their upscaling to ecosystems and identify the role of stem CH 4 emissions in global CH 4 budgets. [Display omitted] [ABSTRACT FROM AUTHOR]

Cycads, which primarily consist of the families Cycadaceae and Zamiaceae, possess intrinsic therapeutic attributes that are prominently expressed across their morphological spectrum, including roots, leaves, flowers, and seeds. In Chinese traditional medicine, the leaves of cycads are particularly revered for their profound healing capabilities. This meticulous review engages with existing literature on cycads and presents insightful avenues for future research. Over 210 phytoconstituents have been isolated and identified from various cycad tissues, including flavonoids, azoxy metabolites, sterols, lignans, non-proteogenic amino acids, terpenoids, and other organic constituents. The contemporary pharmacological discourse highlights the antineoplastic, antimicrobial, and antidiabetic activities inherent in these ancient plants, which are of particular importance to the field of oncology. Despite the prevalent focus on crude extracts and total flavonoid content, our understanding of the nuanced pharmacodynamics of cycads lags considerably behind. The notoriety of cycads derived toxicity, notably within the context of Guam's neurological disease cluster, has precipitated an established emphasis on toxicological research within this field. As such, this critical review emphasizes nascent domains deserving of academic and clinical pursuit, whilst nested within the broader matrix of current scientific understanding. The systematic taxonomy, traditional applications, phytochemical composition, therapeutic potential, and safety profile of cycads are holistically interrogated, assimilating an indispensable repository for future scholarly inquiries. In conclusion, cycads stand as a veritable treasure trove of pharmacological virtue, displaying remarkable therapeutic prowess and holding vast promise for ongoing scientific discovery and clinical utilization. Cycads represent a rich, therapeutic resource, exhibiting exceptional medicinal efficacy and enormous potential for continued exploration and application. [Display omitted] • Up to now, more than 210 phytochemicals have been identified from cycads. • Cycads is a double-edged sword, and its toxicity should not be overlooked. • Cycads has great medical development and application value. [ABSTRACT FROM AUTHOR]

A silicified gymnospermous wood, Protophyllocladoxylon zhaobishanensis sp. nov., is described from the Induan (Lower Triassic) Jiucaiyuan Formation in Zhaobishan section, Shanshan County, southern Bogda Mountains, Xinjiang Uygur Autonomous Region, northwestern China. The pycnoxylic wood contains thick-walled tracheids and parenchymatous ray cells. It is characterized by uni- to triseriate araucarian radial tracheidal pitting, uniseriate rays, one to two large, simple pits in each cross-field, and uni- to biseriate tangential tracheidal pits. The presence of distinct and extensive growth rings in all fossil woods from the Induan of the research area were probably caused by the seasonal climate with great precipitation variability during the earliest Triassic in the Turpan–Hami Basin. This is also supported by the occurrence of Calcisols, vertic Calcisols, and calcic Argillisols from coeval deposits nearby. The occurrence of fossil wood with anatomical structures from the Induan confirms that woody gymnosperms, probably conifers, were crucial elements on the Early Triassic landscape in northeastern Pangaea. It appears that some gymnosperms had survived the end-Permian biotic crisis based on the continuous records of Protophyllocladoxylon -type woods from the Wuchiapingian (upper Permian) to Norian (Upper Triassic) in Bogda Mountains. • A new species of Protophyllocladoxylon wood has been described. • Gymnosperms were crucial elements on the Early Triassic landscape in northeastern Pangaea. • Growth rings on fossil woods and paleosols indicate seasonal environmental stresses. [ABSTRACT FROM AUTHOR]

The Miocene Lake deposit in Clarkia, Idaho is composed of highly fossiliferous silty clays. These rocks were formed in an anoxic and likely toxic deep lacustrine environment which facilitated the fossilization of plant material with a high amount of morphological detail. Many of the plant compression fossils exhibit exceptional preservation, including the preservation of original biomolecules. Pyritized plant specimens are much less common and the details of plant pyritization at this site are not yet fully understood. Pyritized male pollen cones from Taxodium dubium provide an opportunity to explore the processes of pyrite preservation in the Clarkia deposit. One specimen was examined using scanning electron microscopy (SEM) and energy-dispersive x-ray analysis (EDS). The only pyrite textures observed on this specimen were framboids and framboidal microcrystals. Pyrite was found in abundance on the surface of the pollen cones and to a much lesser extent on the surface of the stem. Underneath the pyrite coating, both the cones and stem were carbon-rich, indicating organic preservation. Some pyrite crystals were found in the interior of the stem, but likely originated from the exterior and developed through cracks or tears in the fossil. Pyrite crystals did not form inside the cell walls of the stem. The decaying specimen likely provided a scaffold that could facilitate the formation of pyrite upon the specimen surface. Gypsum crystals found in close association with pyrite likely formed as a product of oxidation after the specimens were taken from the rock. • Two plant fossils preserved with pyrite were found in Clarkia, Idaho. • Pyrite crystals formed either as spherical framboids or associated microcrystals. • Pyrite found only on the exterior of the plant or infilling cracks or tears. • The decaying plant matter formed a scaffold for pyrite formation. • Gypsum found in association with pyrite likely formed after excavation. [ABSTRACT FROM AUTHOR]

Species of Gnetum L. are used for a number of purposes, the most important of which is to make a soup or stew, which is called ‘eru’ in Cameroon. Material is heavily harvested for use in Cameroon, export to Nigeria and to Europe and America. Gnetum has been extirpated in some areas and is becoming rare in others because levels of harvesting are unsustainable. Programmes have been initiated to cultivate and domesticate Gnetum . Two additional African species of Gnetum were recently described — one, G. latispicum E.H.Biye, is traded along with G. africanum Welw. and G. buchholzianum Engl., whereas G. interruptum E.H.Biye was not found in the markets. It had been noted that some strains of Gnetum were not harvested because they tasted bitter. It is thus desirable to select good tasting strains of Gnetum for cultivation and domestication. Twenty tasters, who could taste bitterness, scored meals made from different species of Gnetum , from Gnetum that had been bought in geographically separate markets and Gnetum leaves of different ages on a Likert-type scale. When meals are prepared from freshly harvested leaves, there is preference for fresh G. buchholzianum over the other species. Material from some localities was preferred over others and this does not seem to have a geographical pattern, nor correlate to vegetation type or soil type and it is thus concluded that pleasant taste is genetically determined. There is also a preference for young leaves. These preferences contrast with the preferences recorded in Nigeria, because the factors that give fresh material the best taste, give material a shorter shelf life. It is recommend that in cultivation and domestication programmes, taxonomy should be resolved before selecting material and that it should be borne in mind that different factors may have to be prioritized depending on the purpose for which the product will be used. [ABSTRACT FROM AUTHOR]

Taxus spp. are ancient gymnosperms that produce a unique secondary metabolite, namely, taxol, an anticancer drug. JAZ proteins are key regulators of the JA signaling pathway, which control taxol biosynthesis. However, the JAZ proteins of Taxus spp. are poorly studied. In this work, nine JAZ genes from Taxus chinensis were identified using our previous transcriptome data and named as TcJAZ1–TcJAZ9 . Of these nine TcJAZ proteins, eight contain Jas and TIFY domains, and the Jas domain of TcJAZ6 is incomplete. Most TcJAZs and PsJAZs are not related to AtJAZs and OsJAZs. Phylogenetic analysis divided all JAZ proteins from Arabidopsis thaliana , Oryza sativa , Picea sitchensis , and T. chinensis into eight subgroups; gymnosperms JAZs were classified into subgroups V–VIII, and angiosperm JAZs were categorized into subgroups I–V. Three motifs of subgroups VI–VIII were identified in gymnosperm JAZs, indicating that gymnosperm JAZ proteins exhibit a different evolutionary process from those of angiosperms. The expression patterns of nine TcJAZs showed that TcJAZ2/3/8 was a key regulator, indicating their important roles in T. chinensis . Results revealed that gymnosperm JAZs differ from angiosperm JAZs in terms of molecular structure. Three novel conserved motifs were found in TcJAZs and PsJAZs. This study provides a basis for research on JA regulatory system in Taxus spp. and for elucidating the significance of JA signaling pathway to land plants. [ABSTRACT FROM AUTHOR]

We investigated molecular distributions and stable carbon isotopic compositions (δ 13 C) of sedimentary n -alkanes (C 15 C 35 ) in the riverbank and marine surface sediments to trace natural and anthropogenic organic carbon (OC) sources in the eastern Yellow Sea which is a river dominated marginal sea. Molecular distributions of n -alkanes are overall dominated by odd-carbon-numbered high molecular weight n -C 27 , n -C 29 , and n -C 31 . The δ 13 C signatures of n -C 27 , n -C 29 , and n -C 31 indicate a large contribution of C 3 gymnosperms as the main source of n -alkanes, with the values of −29.5 ± 1.3‰, −30.3 ± 2.0‰, and −30.0 ± 1.7‰, respectively. However, the contribution of thermally matured petroleum-derived OC to the sedimentary OC pool is also evident, especially in the southern part of the study area as shown by the low carbon preference index (CPI 25-33 , <1) and natural n -alkanes ratio (NAR, <−0.6) values. Notably, the even-carbon-numbered long-chain n -C 28 and n -C 30 in this area have higher δ 13 C values (−26.2 ± 1.5‰ and −26.5 ± 1.9‰, respectively) than the odd-carbon-numbered long-chain n -C 29 and n -C 31 (−28.4 ± 2.7‰ and −28.4 ± 2.4‰, respectively), confirming two different sources of long-chain n -alkanes. Hence, our results highlight a possible influence of petroleum-induced OC on benthic food webs in this ecosystem. However, the relative proportions of the natural and petroleum-derived OC sources are not calculated due to the lack of biogeochemical end-member data in the study area. Hence, more works are needed to constrain the end-member values of the organic material supplied from the rivers to the eastern Yellow Sea and thus to better understand the source and depositional process of sedimentary OC in the eastern Yellow Sea. [ABSTRACT FROM AUTHOR]

De novo mutation frequency in two Japanese tree species as a function of ambient radiation dose rate. [Display omitted] • Trees in contaminated areas following a nuclear accident were surveyed genetically. • De novo mutations (DNMs) were detected via RADseq, comparing parents and offspring. • Low-dose-rate radiation (up to 6.86 μGy h−1) did not affect the occurrence of DNMs. • Unknown factors other than low-dose-rate radiation had stronger effects on DNMs. • Haploid or phased reference genomes were effective for detecting DNMs. The impact of low-dose-rate radiation on genetics is largely unknown, particularly in natural environments. The Fukushima Dai-ich Nuclear Power Plant disaster resulted in the creation of contaminated natural lands. In this study, de novo mutations (DNMs) in germ line cells were surveyed from double-digest RADseq fragments in Japanese cedar and flowering cherry trees exposed to ambient dose rates ranging from 0.08 to 6.86 μGy h−1. These two species are among the most widely cultivated Japanese gymnosperm and angiosperm trees for forestry and horticultural purpose, respectively. For Japanese flowering cherry, open crossings were performed to produce seedlings, and only two candidate DNMs were detected from uncontaminated area. For Japanese cedar, the haploid megagametophytes were used as next generation samples. The use of megagametophytes from open crossing for next generation mutation screening had many advantages such as reducing exposure to radiation in contaminated areas because artificial crossings are not needed and the ease of data analysis owing to the haploid nature of megagametophytes. A direct comparison of the nucleotide sequences of parents and megagametophytes revealed an average of 1.4 candidate DNMs per megagametophyte sample (range: 0–40) after filtering procedures were optimized based on the validation of DNMs via Sanger sequencing. There was no relationship between the observed mutations and the ambient dose rate in the growing area or the concentration of 137Cs in cedar branches. The present results also suggest that mutation rates differ among lineages and that the growing environment has a relatively large influence on these mutation rates. These results suggested there was no significant increase in the mutation rate of the germplasm of Japanese cedar and flowering cherry trees growing in the contaminated areas. [ABSTRACT FROM AUTHOR]

The emergence of resistant pathogenic bacterial strains has threatened the human beings and already developed remedial measures. Based on the traditional herbal therapeutic history, present study is aimed to assess in vitro and in silico inhibition potential of leaves extracts of Pinus roxburghii and Cedrus deodara against human pathogenic bacteria Staphylococcus aureus, Salmonella typhi and Pseudomonas aeruginosa. Hexane, methanol and acetone extracts of both plants were evaluated against above mentioned bacterial strains employing agar well diffusion technique. While docking analyses were performed to analyze the interaction of vital bioactive compounds and bacterial virulence proteins to get an idea about potential candidates for drug discovery. Both plant extracts exhibited greater antibacterial activities against S. aureus as compared to S. typhi and P. aeruginosa. The activity of different extracts also portrayed the role of polarity of solvent and compound to be extracted in each solvent i.e., activity of hexane extract > methanol > acetone with some variations. MIC (minimum inhibitory concentration) values of P. roxburghii extracts were less than that of C. deodara against tested strains, while variation was observed in MBCs (minimum bactericidal concentrations). Furthermore, molecular docking of studied plants bioactive compounds and bacterial proteins showed strong interactions (binding affinity) i.e., taxifolin > nortrachelogenin > bisabolene > valencene > caryophyllene. Antibacterial efficiencies of P. roxburghii and C. deodara suggested their application as effective therapeutic agents against diseases caused by mentioned bacterial strains. In silico analysis suggests the isolation and usage of bioactive components as potential antibacterial agents/drugs after further experimentations on animals. [ABSTRACT FROM AUTHOR]

The enigmatic fossil Bernettia inopinata from Lower Jurassic strata of Upper Franconia, Germany, has been described as a leaf-like structure a leaf-like structure bearing a proximal cluster of densely spaced, pillow-like objects believed to represent ovules or ovule-containing units. The systematic affinities of B. inopinata have remained unresolved. This paper describes five strobili from Pechgraben near Bayreuth that show fertile units composed of B. inopinata and the delicate leaf-like structure Chlamydolepis lautneri in helical arrangement along a central axis. These fossils provide the first insights into the organization of the B. inopinata reproductive structure and demonstrate that B. inopinata and C. lautneri were produced by the same plant. Moreover, Desmiophyllum gothanii leaves closely associated with the strobili, together with specimens showing C. lautneri and the enigmatic microsporophyll Piroconites kuespertii in organic connection, support the hypothesis that these four taxa represent parts of the same plant. The genus Piroconites with its type-species P. kuespertii is validated. Although certain structural details of the B. inopinata plant are reminiscent of features seen in other gymnosperms, including Bennettitales (i.e. ovule structure, megasporophyll organization, microsporophyll organization), Gnetales (i.e. three-locular synangia, pollen, leaves), Glossopteridales (megasporophylls), and conifers (microsporophyll organization and arrangement), it does not fit well into any of the known groups of gymnosperms. [ABSTRACT FROM AUTHOR]

Three classes of integral proteins termed oleosin, caleosin and steroleosin have been identified in seed oil bodies of diverse angiosperm species. Recently, two oleosin isoforms and one caleosin were identified in megagametophyte oil bodies of pine ( Pinus massoniana ), a representative gymnosperm species. In this study, a putative steroleosin of approximately 41 kDa was observed in isolated oil bodies of pine megagametophytes, and its corresponding cDNA fragment was obtained by PCR cloning and further confirmed by mass spectrometric analysis. Phylogenetic tree analysis showed that pine steroleosin was evolutionarily more closely-related to steroleosin-B than steroleosin-A found in angiosperm seed oil bodies. As expected, artificial oil bodies constituted with recombinant steroleosin over-expressed in Escherichia coli were less stable and larger than native pine oil bodies. Filipin staining of artificial oil bodies sheltered by recombinant steroleosin with or without its sterol binding domain showed that the sterol binding domain was responsible for the sterol binding capability of steroleosin. Sterol-coupling dehydrogenase activity was demonstrated in artificial oil bodies constituted with recombinant steroleosin as well as in purified pine oil bodies. [ABSTRACT FROM AUTHOR]

Permineralized fossil woods were discovered in a Miocene sedimentary lake sequence in Panotla, Tlaxcala. The objective of this work is to present the description and identification of permineralized woods found in Miocene strata of Tlaxcala and discuss their biogeographical importance. The fossils were prepared using the thin section technique and identified using wood anatomy. The woods were identified as belonging to the genus Podocarpus, with a new species, Podocarpus mexicanoxylon sp. nov Castañeda-Posadas. This record is of great importance because: a) Its presence demonstrates the presence of the ecotone of the tropical montane cloud forest and b) This report supports the presence of this genus at low latitudes in North America (Mexico), where it was unknown until now. • Podocarpus is a predominant genus of the humid forests of Mexico. • In Mexico, the fossil record based on macrofossils of Podocarpus is scarce. • Tlaxcala is one of the few fossiliferous localities of the Miocene of Mexico. [ABSTRACT FROM AUTHOR]

Charcoal, a common product of wildfire, is abundant in many sedimentary rocks deposited in a wide range of environments, from terrestrial to marine. The analysis of paleofloras and the related paleoecological conditions is of great importance for the understanding of past environmental and paleoclimatic events. Woody charcoal is identified from the early Paleogene sediments of the Gurha lignite mine (Palana Formation), Bikaner, Rajasthan. This evidence is in the form of fragments of tracheids and vessels that show homogenized cell walls and well-preserved anatomical details, like pitting on cell walls, characteristic features of charcoal. These charcoal remains, most of which belong to angiosperms, represent the first verified occurrence of paleo-wildfires in this region during the early Paleogene. Moreover, a gymnospermous taxonomic affinity can be established for some of the charred woods and a relationship with conifers is likely, thus providing additional evidence for the taxonomic composition of early Paleogene floras in this region. Consecutively, the presence of diterpenoid compounds together with the occurrence of (mega-)sporinite in the lignite samples also shows the presence of gymnosperm vegetation (conifers). Furthermore, the petrographic composition reveals that the lignite samples are dominated and sub-dominated by the huminite (av. 43.2 vol%) and inertinite (av. 39 vol%) groups, respectively, followed by liptinite (av. 13.9 vol%) group of macerals. Fusinite, semifusinite (and inertodetrinite) macerals are commonly considered as fossil charcoal. The relatively higher content of these macerals in the studied lignite indicates the regular events of palaeofire during the deposition. Subsequently, the presence of unsubstituted polycyclic aromatic hydrocarbon (PAH) compounds identified in samples further suggests the occurrence of fire. Additionally, the inertinite (fusinite) reflectance indicates that the charcoal/inertinite was formed at a temperature above 300 °C, while the highest reflectance value suggests a burning temperature of ∼800 °C. [ABSTRACT FROM AUTHOR]

Simple sequence repeats (SSRs) from a public database were surveyed to identify potential EST-SSR markers for Taxus cuspidata . A total of 5.4 gigabase pairs of RNA-sequencing data were downloaded and assembled into 179,687 contigs, 7404 (4.1%) of which contained SSR sequences. One hundred and fifty PCR primer pairs were designed for SSRs with repeat numbers ≥9 and screened for variation in 18 T. cuspidata trees. Eighty markers showed length variation, with numbers of alleles and expected heterozygosity ranging from 2 to 11 and 0.056 to 0.907, respectively. These EST-SSR markers are expected to be useful for studying the genetic diversity and conservation of Taxus genetic resources. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA), a widespread pollutant, is reportedly harmful to humans, animals and plants. However, the effect of BPA on plant pollen tube growth, as well as the mechanism involved, remains unclear. Here, we report that BPA significantly inhibited Picea meyeri pollen germination and tube elongation in a dose-dependent manner. Transmission electron microscopy showed that BPA was detrimental to organelles such as mitochondria and Golgi apparatus. Non-invasive detection revealed that BPA inhibited extracellular Ca 2+ influx and promoted intracellular Ca 2+ efflux at the pollen tube tip, thereby inducing a dissipated Ca 2+ gradient. Fluorescence labeling showed that BPA disorganized actin filaments (AFs), which subsequently led to abnormal vesicle trafficking. Furthermore, BPA reduced the activity of acid phosphatase, a typical exocytosis enzyme. Moreover, Fourier transform infrared (FTIR) analysis and subsequent fluorescence labeling revealed that BPA induced an abnormal deposition of cell wall components, including pectins and callose. Taken together, our results indicate that BPA, a ubiquitous environmental pollutant, disturbs Ca 2+ flux in P. meyeri pollen tubes, thus disrupting AF organization, resulting in abnormal actin-dependent vesicle trafficking and further affecting the deposition of cell wall components. These findings provide new insight into the mechanism of BPA toxicity in pollen tube tip growth. [ABSTRACT FROM AUTHOR]

A virus from a symptomatic plant of the gymnosperm Welwitschia mirabilis Hook. growing as an ornamental plant in a domestic garden in Western Australia was inoculated to a plant of Nicotiana benthamiana where it established a systemic infection. The complete genome sequence of 9636 nucleotides was determined using high-throughput and Sanger sequencing technologies. The genome sequence shared greatest identity (83% nucleotides and 91% amino acids) with available partial sequences of catharanthus mosaic virus, indicating that the new isolate belonged to that taxon. Analysis of the phylogeny of the complete virus sequence placed it in a monotypic group in the genus Potyvirus . This is the first record of a virus from W. mirabilis , the first complete genome sequence of catharanthus mosaic virus determined, and the first record from Australia. This finding illustrates the risk to natural and managed systems posed by the international trade in live plants and propagules, which enables viruses to establish in new regions and infect new hosts. [ABSTRACT FROM AUTHOR]

Terpene synthase (TPS) analysis may contribute to a better understanding of terpenoids biosynthesis and the evolution of phylogenetic taxonomy. Chamaecyparis formosensis Matsumura is an endemic and valuable conifer of Taiwan. Its excellent wood quality, fragrance, and durability make it become the five precious conifers in Taiwan. In this study, three sesquiterpene synthase genes that belong to the TPS-d2 clade were isolated and characterized through in vitro reaction of recombinant protein and in vivo reaction of Escherichia coli heterologous expression system. The main product of Cf-GerA was germacrene A using GC/MS analysis, while the product of Cf-Aco and Cf-Gor were identified as acora-4(14),8-diene and (5 R ,6 R ,10 S)-α-gorgonene by using NMR analysis. These are the first reported enzymes that biosynthesize acora-4(14),8-diene and (5 R ,6 R ,10 S)-α-gorgonene. Both sesquiterpene synthases may isomerize the farnesyl pyrophosphate substrate to nerolidyl pyrophosphate for further cyclization. Cf-Aco may catalyze 1,6-cyclization of nerolidyl cation while Cf-Gor may catalyze through an uncharged intermediate, isogermacrene A. [Display omitted] • Three sesquiterpene synthases were characterized from Chamaecyparis formosensis. • Two of acora-4(14),8-diene and (5 R ,6 R ,10 S)-α-gorgonene synthase genes, Cf-Aco and Cf-Gor, have firstly found activities. • Though Cf-Aco and Cf-Gor share high identities, they may have unlike reaction mechanisms. [ABSTRACT FROM AUTHOR]

Aromatic hydrocarbons in 36 shales from the late Miocene-early Pliocene strata of the Yinggehai Basin in the South China Sea were investigated. Various higher plant-derived aromatic hydrocarbons were identified, including cadalene, retene, 1,2,7-trimethylnaphthalene, 1-methylphenanthrene (MP), 1,7-dimethylphenanthrene (DMP), 6-isopropyl-1-isohexyl-2-methylnaphthalene, and other polycyclic aromatic hydrocarbons (PAHs). Higher plant parameters suggest that the relative abundance of terrigenous organic matter in the early Pliocene was lower than in the angiosperm-dominated late Miocene Huangliu Formation. Various plant parameters including retene/(retene + cadalene), 1-MP/9-MP, 1,7-DMP/(1,3- + 3,9- + 2,10 + 3,10-DMP), and the higher plant index, indicate that gymnosperms made a larger contribution to the organic matter when the lower Yinggehai Formation was deposited during the early Pliocene. Combustion-derived PAHs, including fluoranthene, benzo[ a ]anthracene, benzofluoranthenes and coronene, predominate over petrogenic PAHs in the lower Yinggehai Formation and the upper Meishan Formation, indicating that there were more wildfires during deposition of these units compared to the Huangliu Formation. In contrast, there is a mixed input of combustion-derived and petrogenic PAHs in the Huangliu Formation. As also supported by higher abundances of Pinus in palynological records, the combustion-derived PAHs and the gymnosperm/angiosperm parameters provide unequivocal evidence for a cooling climate from the late Miocene to the early Pliocene in the South China Sea. • Aromatic gymnosperm-derived hydrocarbons more abundant in the early Pliocene. • More combustion-derived PAHs than petrogenic PAHs in the early Pliocene. • Cooling and dryer climate occurred from the late Miocene to the early Pliocene. [ABSTRACT FROM AUTHOR]

Abstract: The Bletterbach flora is the most important late Permian (Lopingian) flora of the Southern Alps. The study of a new fossiliferous bed stratigraphically below the cephalopod bed yielded almost 500 plant fossils, 28 of which belong to rare Lopingian plant groups: horsetails, seed ferns and possible cycads. Forty-five other fossils from the collection of Utrecht University were examined. The study of these more than fossils reveals a higher diversity of seed ferns and putative cycadophytes in the Lopingian of Europe than previously documented. Horsetails are represented by dispersed sporophylls, stem fragments and leaf sheaths too badly preserved for attribution to a species. Seed ferns are represented by Sphenopteris and the new genus Germaropteris, which includes G. martinsii (Germar in Kurtze 1839) Kustatscher, Kerp et Van Konijnenburg-van Cittert comb. nov., a species from the German Zechstein formerly assigned to various genera (e.g., Callipteris, Lepidopteris, Peltaspermum). Two species of Sphenopteris (S. suessii, S. sp.) are recorded for the first time from Lopingian strata of the Southern Alps. Remarkable are pinnae with alethopteroid pinnules, because similar forms have not been described from Lopingian deposits of Europe. Putative cycadophytes are represented by two taeniopterid leaves (Taeniopteris sp. A and T. sp. B) and a fragment of a pinnate cycad-like leaf. The Bletterbach flora is one of the most diverse European Lopingian floras, at least with regard to the non-conifer taxa. The floras of the Germanic Zechstein Basin and of the Southern Alps are more similar than previously considered, notwithstanding the vicinity of the latter region to the northern margin of the Palaeotethys; there are no obvious similarities to the floras that occurred along the southern margin of the Palaeotethys. In Europe, plant fossils are generally very rare in Lopingian strata and the presence of plant fossils in the Zechstein Basin and the Southern Alps is apparently related to sea-level changes. They appear to be most common immediately before and after the maximum transgression or sea-level high-stand. [Copyright &y& Elsevier]

Abstract: Glutathione transferases (GSTs), which are ubiquitous in plants, play a major role in the detoxification of xenobiotics and oxidative stress metabolism. Due to their role in herbicide detoxification, previous studies of plant GSTs have mainly focused on agricultural plants. In contrast, functional information regarding gymnosperm GSTs is scarce. In this study, we cloned 27 full-length GST genes from the deciduous conifer Larix kaempferi, which is widely distributed across the cooler regions of the northern hemisphere. As with the angiosperm GST gene family, Larix GSTs are divided into eight classes, and tau class GSTs are the most numerous. Compared to the other seven classes of GSTs, Larix tau GST genes show substantially more variation in their expression patterns. The purified Larix GST proteins showed different substrate specificities, substrate activities, and kinetic characteristics. The pH and temperature profiles of purified Larix GST proteins showed broad optimum pH and temperature ranges for enzymatic activity, suggesting that Larix GSTs have evolutionary adaptations to various adverse environments. Taken together, this study provides comprehensive insight into the gymnosperm GST gene family. [Copyright &y& Elsevier]

Highlights: [•] Stephanospermum trunctatum from late Permian flora of South China reinvestigated. [•] New species of Stephanospermum documented from the Wangjiazhai Formation China. [•] Late Permian species of Stephanospermum represent Lazarus taxa. [•] Lower and middle Permian range hiatus termed the Stephanospermum gap. [•] Stephanospermum occupied unknown refugia during the Stephanospermum gap. [ABSTRACT FROM AUTHOR]

Abstract: The degree to which carbon concentration (CC) of woody detritus varies by tree taxa, stage of decay, tissue type (i.e., bark versus wood), and vertical orientation was examined in samples of 60 tree species from the Northern Hemisphere. The mean CC of 257 study samples was 49.3% with a range of 43.4–56.8%. Angiosperms had a significantly lower CC than gymnosperms, with means of 47.8% and 50.6%, respectively. For whole-stems (i.e., wood and bark), the CC of gymnosperms significantly increased from 49.3% to 53.5% with decomposition, while angiosperms had no significant change. The CC of bark was higher than wood across all stages of decay by an average of ∼1.0%. A similar magnitude of difference was found for standing versus downed dead wood in the later stages of decay, with the former having a higher CC than the latter. Differences between angiosperms and gymnosperms are hypothesized to be associated with initial lignin concentrations as well as subsequent decomposition by white- versus brown-rot fungal functional groups. The higher abundance of brown-rots in decomposing gymnosperms may lead to an increase in lignin concentrations, a compound that has higher CC than cellulose. As a result of these findings, uncertainties associated with forest carbon inventories may be reduced by using detrital CC specific to general taxa (angiosperms versus gymnosperms) and stage of decay rather than a single assumed value of 50% as commonly practiced. [Copyright &y& Elsevier]

Abstract: An exquisitely well-preserved woody stem from northern China provides additional evidence for the biodiversity of latest Permian of the Cathaysian flora. The specimen of Ningxiaites specialis gen. nov. et sp. nov. was collected from the Sunjiagou Formation in the Shitanjing coalfield, Ningxia Hui Autonomous Region. The permineralised plant is featured by a eustelic vascular system, thick pycnoxylic woody cylinder, and prominent helically arranged clusters of leaf traces. The circular parenchymatous pith is surrounded by more than 30 endarch primary xylem strands and numerous distinctive leaf traces. Leaf traces initiate from the pith margin singly, bifurcate immediately or remain as a single bundle when crossing the wood cylinder. The wood is especially characterised by the development of inflated cells and pitted tangential (terminal/end) wall of ray cells. The new plant is tentatively assigned to the conifers although it shows few similarities with ginkgophytes, which might indicate the early conifer and ginkgophyte woods could be very similar to each other. Spheroidal and oval coprolites preserved in its pith and adjacent xylem is interpreted as having an oribatid mite origin. [Copyright &y& Elsevier]

Abstract: Plant phi class glutathione transferases (GSTs) play important roles in stress tolerance and detoxification metabolism. This study reports the cloning, expression and biochemical characteristics of a phi GST gene (CaGSTF) from the endemic and endangered conifer Cathaya argyrophylla. The recombinant CaGSTF showed GSH-conjugating activity towards the substrate NBD-Cl and CDNB. Kinetic analysis revealed low catalytic efficiency with a k cat/K m GSH value of 9.82 mM−1S−1. The CaGSTF proved to be a thermolabile enzyme, at 40°C the enzyme’s activity was nearly abolished. Site-directed mutagenesis revealed that Ser12, Lys42, Ile55, Glu67 and Ser68 of CaGSTF are critical components of glutathione-binding sites that contribute to the enzyme’s catalytic activity. Compared to other plant phi GSTs and conifer tau GSTs, CaGSTF showed a narrow substrate spectrum, low catalytic efficiency and thermolability. These atypical properties suggest the enzyme may have a limited functional role in the organism’s adaptation to environmental stresses in the subtropical regions. [Copyright &y& Elsevier]

• Leaf unfolding of male and female ginkgo responses similarly to climate. • Long photoperiod significantly shortened the time to leaf unfolding. • Effects of temperature and photoperiod on leaf unfolding decreased along elevations. Climate change substantially affects plant phenology, resulting in earlier vegetation onset across temperate and boreal regions. Phenological shifts caused by warming may alter species interactions across trophic levels because of species-specific responses, and influence the reproductive success of dioecious species if the phenological sensitivity to warming (S T) differs between genders. We used twigs collected from male and female gingko trees at three elevations on Tianmu Mountain in eastern China. The twigs were cultivated in climate chambers to determine the effects of three temperatures (10, 15, and 20 °C) and two photoperiods (8 and 16 h). We observed slightly earlier leaf unfolding dates in male twigs (1 day), and a higher heat requirement (growing degree hours) for leaf unfolding in female (14,334 ± 588 °C) compared to male twigs (13,874 ± 551 °C). Similar responses to temperature (S T = 3.7 days °C−1), photoperiod and elevation were observed across genders. The long photoperiod treatment shortened the time to leaf unfolding by 9.1 days, but temperature and photoperiod effects on leaf unfolding differed significantly depending on the elevation of the donor trees. Specifically, S T was higher (4.17 days °C−1) and the photoperiod effect on S T was larger (decreased by 1.15 days °C−1) at the lowest elevation than at the higher elevations (S T = 3.26 days °C−1; decreased by 0.48 days °C−1). This may be related to environment-induced local adaptations and self-protection mechanisms of trees at high elevations to avoid frost damage. Our results indicate that the photoperiod and genetic adaptations to local environments influenced the warming-induced phenological responses in ginkgo, but these responses were generally similar between the genders. For a given species, individuals in different climates may exhibit different phenological responses to higher temperatures, with individuals in warmer regions likely becoming increasingly limited by the photoperiod as the climate warms further. [ABSTRACT FROM AUTHOR]

The sedimentary geochemical records of palaeovegetation and palaeoclimate variations in late Miocene-early Pliocene sediments in the Ying-Qiong Basin, South China Sea have been studied using higher plant-derived biomarkers, palynological records, trace elements, and macerals. Aliphatic biomarkers including oleanane, des -A-oleanane, bicadinanes, and C 19 tricyclic terpane, and the vitrinite content of the kerogen, show a remarkable decline in the input of the main angiosperms from about 8.2 to 2.7 Ma, corresponding to the deposition of the upper Huangliu Formation (late Miocene) to the lower Yinggehai Formation (early Pliocene). Aromatic parameters including retene/(retene + cadalene), 1,2,5-TMN/1,3,6-TMN, 1-MP/9-MP and 1,7-DMP/(1,3- + 3,9- + 2,10- + 3,10-DMP) suggest that the upper Huangliu Formation received a greater gymnosperm contribution than older Miocene formations. Trace element ratios (Rb/Sr and Zr/Rb) and the proportion of alginite-amorphous macerals in the shales indicate that a cooler, more arid climate with less seasonal precipitation occurred progressively from about 8.2–2.7 Ma, as also supported by higher abundances of Pinus and Alnus and decreasing proportions of ferns in the flora. Lesser input of terrigenous higher plants and the variation in vegetation types occurred during a cooling climate that was likely associated with a weaker East Asian summer monsoon and uplift of the northern Tibet-Plateau from about 8.5 Ma. • Palaeoclimate and palaeovegetation in Ying-Qiong Basin (S. China) reconstructed. • Higher gymnosperm/angiosperm and more Pinus in flora from 8.2–2.7 Ma. • From late Miocene to early Pliocene there was a cooling and drying climate. • Weakening East Asian summer monsoon occurred from 8.2–2.7 Ma. [ABSTRACT FROM AUTHOR]

Abstract: Mitochondria were isolated from embryogenic cell cultures of Araucaria angustifolia, an ancient gymnosperm. The mitochondria obtained oxidized NADH and succinate as respiratory substrates and were able to sustain a high transmembrane electrical potential. They were able to take up Ca2+ supported by substrate oxidation, sensitive to ruthenium red and dependent on membrane potential. The influx of the ion was Pi dependent and at least one efflux pathway was demonstrated by ruthenium red addition. The mitochondria also oxidized externally added NADH, and presented oxygen consumption insensitive to cyanide and sensitive to salicyl hydroxamic acid (SHAM) suggesting the presence of external NADH dehydrogenase and alternative oxidase (AOX), respectively. Besides, mitochondria were uncoupled, in the absence of BSA, by the addition of oleic acid suggesting the presence of the plant uncoupling mitochondrial protein. [Copyright &y& Elsevier]

Abstract: 1-Aminocyclopropane-1-carboxylate (ACC) synthase catalyzes what is typically the rate-limiting step in the biosynthesis of ethylene, a gaseous plant growth regulator that plays numerous roles in the growth and development of higher plants. Although ACC synthase genes have been characterized from a wide variety of angiosperm plant species, no ACC synthase genes have been described previously for gymnosperms. Evidence suggests that ethylene helps to regulate wood formation in trees, and may also signal for the metabolic shifts that lead to compression wood formation on the undersides of branches and leaning stems in gymnosperm trees. Since compression wood is an inferior feedstock for the manufacturing of most wood products, a better understanding of the factors influencing its formation could lead to substantial economic benefits. This study describes the isolation and characterization of a putative ACC synthase gene, PtaACS1, from loblolly pine (Pinus taeda L.), an important commercial forest tree species. Also described is an apparent splice variant of PtaACS1 (PtaACS1s) that is missing 138 bp from the 5′ end of the transcript, including bases that encode a conserved amino acid residue considered critical for ACC synthase activity. The two sequences share interesting homologies with a group of plant aminotransferases, in addition to ACC synthases, but structural models and the conservation of critical catalytic amino acid residues strongly support PtaACS1 as encoding an active ACC synthase. The two transcripts were differentially expressed in various tissues of loblolly pine, as well as in response to perturbations of pine seedling stems. Transcript levels of this ACC synthase gene increased rapidly in response to bending stress but returned to near starting levels within 30 min. It remains unclear to what extent bending-induced expression of this gene product plays a role in compression wood formation. [Copyright &y& Elsevier]

Abstract: Geranyl diphosphate (GPP), the universal precursor of monoterpenes, is formed from isopentenyl diphosphate and dimethylallyl diphosphate by the action of geranyl diphosphate synthase, one of the key branchpoint enzymes of terpene biosynthesis. Three types of GPP synthase can be distinguished in plants based on sequence similarity and subunit architecture, but until now individual species have been reported to contain only one of these types. Here we show that the conifer, Norway spruce (Picea abies), contains two different types of GPP synthase belonging to two separate groups of homodimeric proteins. One enzyme, designated PaIDS2 (P. abies isoprenyl diphosphate synthase 2), has high sequence similarity to other gymnosperm GPP synthases. It produces solely GPP in in vitro assays after expression in Escherichia coli and likely participates in monoterpene biosynthesis accompanying induced oleoresin formation, based on dramatic increases in transcript level after methyl jasmonate application. The other enzyme, designated PaIDS3, has highest similarity to the previously reported Arabidopsis thaliana GPP synthase and several other angiosperm sequences, and is not associated with induced oleoresin formation in Norway spruce. In vitro assay of this protein and one encoded by a similar gene sequence from Quercus robur gave substantial amounts of the larger prenyl diphosphates, FPP and GGPP, in addition to GPP. Hence these proteins may not be involved in monoterpene formation and could conceivably form products in addition to GPP in planta. [Copyright &y& Elsevier]

Abstract: The conifer Picea abies (Norway spruce) employs terpenoid-based oleoresins as part of its constitutive and induced defense responses to herbivores and pathogens. The isoprenyl diphosphate synthases are branch-point enzymes of terpenoid biosynthesis leading to the various terpene classes. We isolated three genes encoding isoprenyl diphosphate synthases from P. abies cDNA libraries prepared from the bark and wood of methyl jasmonate-treated saplings and screened via a homology-based PCR approach using degenerate primers. Enzyme assays of the purified recombinant proteins expressed in Escherichia coli demonstrated that one gene (PaIDS 4) encodes a farnesyl diphosphate synthase and the other two (PaIDS 5 and PaIDS 6) encode geranylgeranyl diphosphate synthases. The sequences have moderate similarity to those of farnesyl diphosphate and geranylgeranyl diphosphate synthases already known from plants, and the kinetic properties of the enzymes are not unlike those of other isoprenyl diphosphate synthases. Of the three genes, only PaIDS 5 displayed a significant increase in transcript level in response to methyl jasmonate spraying, suggesting its involvement in induced oleoresin biosynthesis. [Copyright &y& Elsevier]

Abstract: Two kinds of cupulate seed plants are described from the Upper Devonian aged Upper Old Red Sandstone at Taffs Well near Cardiff, South Wales. The first conforms to the characters of Xenotheca devonica (Arber and Goode) Hilton and Edwards previously recognised from the Upper Devonian of North Devon, to which it is assigned. The Taffs Well specimens provide additional information on intraspecific variation within this morphospecies that is now known to possess 4–8 preintegumentary lobes in the distal 50–66% of preovule length. This represents the first occurrence of this morphospecies outside the type locality and highlights the morphological similarities observed in the morphogenera Xenotheca and Moresnetia and the genus Elkinsia. Cupules of the second kind occur terminally on a cruciately dichotomous branching system and have distinctive long and thin cupule tips. Cupules bear at least one asymmetric preovule that comprises an entire integument in the proximal 90% of preovule length and distally possess ca. 4 short and wide preintegumentary lobes. Features of its cupule and integument are distinct from all other recognised early seed plants leading to the establishment of Glamorgania gayerii gen. et sp. nov. Glamorgania shows that by the onset of the Carboniferous some seed plants had attained an almost complete integumentary surround. These records add to the growing body of data on the earliest seed plants and their initial phase of phenotypic radiation in the Upper Devonian. This investigation also highlights the problems of accommodating preservational differences in schemes of palaeobotanical nomenclature, from which it is concluded that Glamorgania may correspond to the compression/impression equivalent of the anatomically preserved Mississippian morphogenus Eurystoma. [Copyright &y& Elsevier]

Abstract: Glutathione transferases (GSTs) play important roles in stress tolerance and detoxification metabolism in plants. To date, studies on GSTs in higher plants have focused largely on agricultural plants. In contrast, there is virtually no information on the molecular characteristics of GSTs in gymnosperms. The present study reports for the first time the cloning, expression and characteristics of a GST gene (PtGSTU1) from a pine, Pinus tabulaeformis, which is widely distributed from northern to central China covering cold temperate and drought regions. The PtGSTU1 gene encodes a protein of 228 amino acid residues with a calculated molecular mass of 26.37 kDa. Reverse transcription PCR revealed that PtGSTU1 was expressed in different tissues, both above and below ground, of P. tabulaeformis. The over-expressed recombinant PtGSTU1 showed high activity towards the substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl). Kinetic analysis with respect to CDNB as substrate revealed a Km of 0.47 mM and Vmax of 169.1 μmol/min per mg of protein. The recombinant PtGSTU1 retained more than 60% of its maximum enzymatic activity from 15°C to 45°C with a broad optimum Tm range of 25°C - 35°C. The enzyme had a maximum activity at approximately pH 8.5 - 9.0. Site-directed mutagenesis revealed that Ser13 in the N-terminal domain is a critical catalytic residue, responsible for stabilisation of the thiolate anion of enzyme-bound glutathione. Based on comparative analyses of its amino acid sequence, phylogeny and predicted three-dimensional structure, the PtGSTU1 should be classified as a tau class GST. [Copyright &y& Elsevier]

Hundreds of silicified standing stumps have been discovered within a lignitic horizon in the middle of the Tienen Formation near Hoegaarden in northeast Belgium. The anatomical features of the fossil stumps, as those of the numerous silicified secondary xylem remains collected since the last century from this area, demonstrate that they all belong to a single taxodiaceous taxon. The stumps bear characteristics shared by Taxodioxylon gypsaceum and Glyptostroboxylon tenerum, but affinities with the latter appear closer. They are attributed to Glyptostroboxylon sp. Calibration of the sedimentological, stratigraphical and organic carbon isotope data reveals that these taxodiaceous fossil trees developed in a swampy lowland environment most probably during the Initial Eocene Thermal Maximum at ca. 55 Ma. [Copyright &y& Elsevier]

Two new species of the gymnospermous leaf form-genus Rochipteris Herbst, Troncoso and Gnaedinger are described. Leaves belonging to this genus are apetiolate, flabellate, with an entire to variably dissected apex, a truncate to slightly flaring base, and sparsely anastomosing venation. Rochipteris etheridgei (Arber) comb. nov. is documented from Carnian sediments of the Leigh Creek Coal Measures, South Australia. Rochipteris ginkgoides sp. nov. is described from the Ipswich Coal Measures (Carnian) Queensland, Australia. A single additional incomplete leaf from the Triassic Springfield Basin, South Australia is assigned to Rochipteris sp. These fossil leaves have previously been assigned to a range of genera based on leaf shape and apparent dichotomous venation. Rochipteris species represented a sub-dominant component of the Dicroidium-rich lowland vegetation across Gondwana during the Late Triassic. [Copyright &y& Elsevier]

To better understand the molecular mechanisms controlling development of sexual characters in Cycas edentata, we attempted to clone genes expressed differentially in male or female reproductive organs. We report a novel gene, named Fortune-1 (Ft-1), with enhanced expression in male reproductive organs. The 593-base-pair Ft-1 cDNA is predicted to encode a 77-amino-acid protein, and exists as a single copy gene in the C. edentata genome. Ft-1 expression is enhanced in male cones, including the cone axis, microsporophylls and microsporangia, but is reduced in ovules and undetectable in megasporophylls. Ft-1 is also weakly detectable in leaves. In roots and stems of C. edentata, Ft-1 transcripts are undetectable. The secondary structure prediction and homology search of Ft-1 protein show that it has a helix–loop–helix motif, and is without any homologue in the database. [Copyright &y& Elsevier]

New material of the enigmatic plant Saportaea salisburioides Fontaine et White 1880 is described from three localities in the late Permian Umm Irna Formation from the Dead Sea region, Jordan. The preservation and the sedimentology indicate that remains from all three localities were transported over a very short distance. In one of the localities the rich leaf association exclusively comprises Saportaea remains, which show a remarkably large morphological variation. They occur together with a coaly axis with attached petioles and several isolated petioles. The specimens apparently belonged to a single monospecific stand, or maybe even a single plant. Another locality yielded a large leaf portion showing the leaf architecture. Our material leads to the conclusion that Saportaea grandifolia Fontaine et White 1880 and Baiera virginiana Fontaine et White 1880 are to be regarded as synonyms of S. salisburioides. In one locality Saportaea foliage was found in close association with Nystroemia sp., which might suggest that this fructification belongs to Saportaea. Saportaea is a long-ranging, geographically widely distributed but very rare genus that first appears in the Westphalian D (Moscovian, Pennsylvanian) and has its last occurrence in the Carnian (Late Triassic). • Enigmatic Paleozoic species emerges 50–60 Ma after only known occurrence. • Evidence for natural relationship. • New data on leaf morphology and growth habit. • Rare glimpse of a vegetation type that normally remains hidden. [ABSTRACT FROM AUTHOR]

• Plant waxes of the drought-tolerant conifer Juniperus monosperma were studied. • Temperature (T) and precipitation (P) were manipulated for mature trees. • Higher T resulted in greater n -alkane concentrations, but not for other waxes. • Decreased P did not affect plant wax concentrations. • Average chain length (ACL) was not affected by T or P. Plant waxes, including n -alkanes, are commonly used for a wide range of paleo-applications. Several common traits of n -alkanes that are used as paleo-proxies include chain length distribution and average chain length (ACL), as well as plant wax carbon and hydrogen isotopic compositions. The effect of climate on plant wax traits has been the subject of many studies, but a common challenge with modern calibrations is disentangling the effects of species (genetic), temperature, and precipitation from one another. Here, we explore the effect of temperature and drought, independently and combined, on plant wax composition of the species Juniper monosperma in a large ecosystem-scale field manipulation experiment. We find that n -alkane concentrations significantly increase with temperature, but other parameters (including ACL) are not affected. These results support physiological studies that identify n -alkanes as an important barrier to water loss within the plant cuticle. Combined with prior studies, it appears that changes in ACL within sediments are likely controlled by changes in species composition rather than directly by changes in climate. We find little variation in the carbon isotopic composition (δ13C) of n -alkanes across the treatments whereas bulk leaf δ13C values are higher in the heat and drought treatment. Because leaf δ13C values represent a weighted C assimilation signal, these values reflect differences in leaf gas exchange among treatments, whereas the n -alkanes are synthesized when water availability is higher and differences among treatments are not significant enough to influence their values. These results have important implications for using n -alkane traits, including ACL and δ13C values, for paleoenvironmental reconstructions. [ABSTRACT FROM AUTHOR]

The biomarker and aromatic compounds, including polycyclic aromatic hydrocarbons (PAHs), in three oil families composed of 29 crude oils from the Gippsland Basin, SE Australia were studied using gas chromatography-mass spectrometry. Environment-related parameters, such as the Pr/Ph ratio and the gammacerane index, indicate that all the oils originated from a lacustrine/fluvial-deltaic environment with fresh water. Thermal maturity-related parameters, including aliphatic and aromatic maturity indicators (e.g. C 29 sterane isomerisation parameters, alkylnaphthalene indices, and methylphenanthrene index), show that all the oils from the GA1 oil family have a similar thermal maturity in the peak-late oil window. However, oils from the GA2 and GB families vary in thermal maturity and are interpreted to be mixtures of less mature and more mature crude oils. Source-related biomarkers (e.g. isopimarane, labdane and phyllocladane) and PAHs (e.g. retene and oleanane-/ursane-/lupane-derived aromatic triterpenoids) suggest that the GA1 oils were mainly derived from source rocks rich in conifer-derived organic matter. The organic matter source of the GA2 and GB oil families included both angiosperms and gymnosperms, with a relatively stronger angiosperm contribution to the organic matter in the source rock(s) of the GB oils, based on the PAH analysis. Moreover, higher plant-derived triterpenoids can be effectively used to correlate oil families across the study area, supplementing the n- alkane carbon isotope and biomarker data of the three oil families reported previously. • Biomarkers and aromatic hydrocarbons in three Gippsland Basin oil groups compared. • Monoaromatic triterpenoids were detected. • Higher plant-derived aromatic triterpenoids are useful for oil-oil correlations. [ABSTRACT FROM AUTHOR]

• In Pinus massoniana sRNA libraries, 53 conserved MicroRNAs and 41 novel MicroRNAs were identified. • With 1966 transcripts, 2606 miRNA-target pairs were predicted. • MicroRNA regulatory network and key modules involved in strobilus development were identified. Pinus massoniana (P.massoniana) is a gymnosperm with important economic value. Strobilus is an important organ for the study of morphogenesis and pattern-building mechanisms at the reproductive stage of conifers. miRNA induced post-transcriptional regulation plays a key role in sex differentiation, strobilus development, fertilization and embryogenesis in gymnosperms. In this study, miRNA profiles of strobili (female and male) and vegetative tissues of P. massoniana were constructed and compared by sRNA-seq. By de novo prediction and manual revision, 53 conserved miRNAs and 41 novel miRNAs were identified, including 30 differentially expressed miRNAs. Comprehensive analysis with computational prediction and degradome data provided 349 genes targeted by 102 miRNAs. The target gene enrichment analysis indicated that signal transduction was significantly activated during strobilus (especially male strobilus) development. The miRNA-target network was constructed and its module miRNA (miR156, 529, 396 and Nov23)- SPLs (SQUAMOSA PROMOTER BINDING PROTEIN-LIKE) seemed to be a key regulator in the differentiation of male strobili from female strobili and vegetative tissues. In addition, the precursor and primary transcripts identified with miRNA quantification indicated that the regulatory mechanism of miRNA abundance is complex and needs to be studied further. This study provides important miRNA and target information for the strobilus of P. massoniana. The de novo prediction method was appropriate for miRNA identification in plants without a reference genome. The significantly activated pathways and miRNA-target networks identified here increase the understanding of the posttranscriptional regulatory mechanism of strobilus differentiation and development in the reproductive phase of conifers. [ABSTRACT FROM AUTHOR]

Height–diameter allometric (H-D) relationships play an important role in the light capture and stability of a tree, and it is poorly understood whether the relationships changes with growth stages or functional groups along a large scale environmental gradients. We present a comparative study of H-D relationships of 6810 seedlings and 19,707 trees from about 1000 species in 9 different sites across China. We showed that allometric exponents for seedlings and trees differ between different sites and do not represent a single, constant theoretical value (e.g. 2/3, 1/2 or 1). Seedlings had greater exponents than trees in most sites. The exponents varied between canopy and understory trees in 5 sites, while were indistinguishable from each other in the remaining 4 sites. Canopy-tree seedlings had smaller exponents than understory-tree seedlings in 3 sites but had indistinguishable exponents in the other 6 sites. Gymnosperm trees had exponents greater than or indistinguishable from angiosperm trees. Elevation alone, or together with mean temperature of the warmest month explained variation of tree allometries for canopy-tree and understory-tree seedlings. The exponents of canopy trees decreased with mean annual precipitation. Our results do not support the predictions from metabolic scaling theory or biomechanical models that height–diameter allometries are invariant. Our study provides insight into how ontogeny, adult stature, phyletic affiliations and environmental limitations affect height–diameter allometric relationships at biogeographical scales. • Height–diameter exponents for seedlings and trees do not represent a constant value. • Seedlings had greater height–diameter exponents than trees in most sites. • Adult stature (canopy and understory trees) affect height–diameter exponents. • Phyletic affiliations (gymnosperm and angiosperm) affect height–diameter exponents. • Elevation, summer temperature and precipitation affect height–diameter exponents. [ABSTRACT FROM AUTHOR]

Permian spore–pollen assemblages are dominated by striate bisaccate pollen grains. The botanical affinity of many of these is unknown, which limits their value in ecological reconstruction and biostratigraphy. Lueckisporites virkkiae Potonié et Klaus 1954 emend. Clarke 1965 is a bitaeniate bisaccate pollen grain of uncertain botanical affinity that dominates late Permian Euramerican assemblages, but also bridges phytogeographical provinces. It is classified into three "variants," which capture a spectrum of morphological variability, but further complicates matters by questioning whether it comprises a natural taxon. Here we report on a TEM analysis of the gross structure and wall ultrastructure of L. virkkiae variants from the upper Permian (Lopingian) of Kimberley, Nottinghamshire, UK. The variants have the same gross structure and wall ultrastructure. The exine consists of a three-layered ektexine composed of a thin tectum, an alveolate infratectum and a thin foot layer, subtended by a solid endexine. Alveolae are either small and rounded, columellate-like, or irregularly shaped, depending on whether the exine is viewed in transverse or longitudinal section. Sacci are protosaccate, with narrow and irregular, or large and voluminous, endoreticulations. Similarities in gross structure and wall ultrastructure suggest that the current taxonomic grouping is correct with the variants representing the range of variation within a single species. We suggest that the differences in morphology are subtle and attributable to harmomegarthy. Comparisons with fossil and modern conifer pollen grains suggest an affinity with conifers. Co-occurrence with the Zechstein conifer macrofossil Pseudovoltzia liebeana (Geinitz) Florin 1880 (Majonicaceae) indicates this as a possible source. • Lueckisporites virkkiae ultrastructure revealed as alveolar and protosaccate. • Lueckisporites virkkiae variants A–C exhibit homologous ultrastructure. • Subtle structural differences between variants due to ontogeny or harmomegarthy. • Distinctive four-layered wall and bisaccate condition point to conifer affinity. • Combined evidence suggests affinity to Pseudovoltzia liebeana (Majonicaceae). [ABSTRACT FROM AUTHOR]

The Chubut Group (Cretaceous) consists of continental volcaniclastic deposits widely distributed in the Golfo San Jorge and Cañadón Asfalto basins of Central Patagonia. In the San Bernardo Fold Belt, numerous outcrops with fossil plants have been historically mentioned. In this contribution, a precise geographical and stratigraphic position of localities with megafloral records was carried out, identifying six plant localities. These fossil assemblages belong to the Matasiete, Castillo and Bajo Barreal formations (Chubut Group) covering a time span ranging from the Aptian ̶ earliest Turonian. The fossiliferous content of each flora is briefly characterized, and the sedimentological context is detailed. Most of these floras have been preserved in proximal floodplain facies, but also occurred as part of debris-flow deposits associated with fluvial channels with high discharge variability. The fossil assemblages are characterized by relatively low species richness. Angiosperms leaves are the main component and their physiognomic traits are homogeneous among floras prevailing microphyll, elongate, untoothed morphotypes. Few gymnosperms and ferns are also present. This study provides a general framework that will support future and more detailed paleobotanical studies, already underway, of each of these floras. • The Chubut Group is a Cretaceous sequence widely distributed in central Patagonia. • In the San Bernardo Fold Belt includes numerous outcrops with fossil plants. • Stratigraphy and sedimentological context of each fossiliferous site is detailed. • The paleobotanical content of each fossiliferous site is here briefly characterized. • A general framework for future detailed paleobotanical studies is provided. [ABSTRACT FROM AUTHOR]

This paper presents the characteristics of source organic matter (OM), hydrocarbon potential (HC) and the depositional system of Gondwana coaly shales in the Carboniferous-Permian succession in drill hole GDH-40, Barapukuria basin, Bangladesh. Twelve layers intercalated in coals and sands were examined using Hydrogen Index (HI) of Rock Eval analysis, biomarkers in saturated HC fractions, polycyclic aromatic hydrocarbons (PAHs), and stable carbon (δ13C org) and nitrogen (δ15N tot) isotope ratios. The coaly shales showed a wide range of total organic carbon (TOC) content (2.3–30.3 wt%), intermediate to high TOC/TN ratios (14–39) and low total sulfur (TS) contents (<0.3 wt%), suggesting deposition in a freshwater environment occasionally influenced by brackish water. OMs with low to moderate HI (20–204 mg HC/g TOC) were deposited in a shallow terrestrial basin. The HC potentials are high in the middle and lower parts of the succession, with increasing TOC content dominated by terrestrial plants. The higher total HC generation potential up to 60.1 mg HC/g is attributed to coaction of high TOC and HI values. The HI values show good positive correlations with Pr/Ph ratios (r = 0.90), n- C >25 / n -C total alkanes (r = 0.86), phenanthrene (r = 0.75), methylphenanthrene (MP, r = 0.75), Tm/Ts (r = 0.74), sterane C 29 /C (27+28+29) (r = 0.69), Pr/ n- C 17 ratio (r = 0.69) and TS (r = 0.68). The coaly shales also contain abundant retene. Higher δ15N ratios coupled with high HI values suggest that the climate had a dry season. Very small amounts of oleanane and low ratios of oleanane/C 30 -hopane show negative correlations with HI values (r = −0.68). A significant input of algae and/or planktonic organisms occurred in the upper part of the core, estimated based on regular sterane compositions, but this did not increase the HI values. Relatively abundant hopanes (steranes/hopanes = 0.11–0.40) implied greater contribution of methanogen in the upper part of the succession and increased activity of aerobic bacteria in the middle to lower parts, respectively. Organic maturity is considered to be in the early to medium stage of oil generation, according to C 29 sterane 20S/(20S + 20R) ratios of 0.28–0.49. Based on these results, most OMs originated from ferns, pteridospermic gymnosperms, peat mosses and/or submerged/floating plants, occasionally supplemented by a specific gymnosperm OM with epicuticular wax. Potential of HC generation of these coaly shales probably increased with increasing deposition of liptinite materials. Fluoranthene (Fla), pyrene (Py), benzo[ e ]pyrene (BePy) and benzo[ bjk ]fluoranthene (Bflas) are abundant PAHs in the coaly shales, and the ratios of low Fla./Py, benzo[ a ]anthracene (BaAn)/228 and indeno[1,2,3- cd ]pyrene/(indeno[1,2,3- cd ]pyrene + benzo[ ghi ]perylene) (InPy/(InPy + BghiP)) suggest that these 4- to 6-ring PAHs were mainly formed by small- to medium-scale wildfires during the dry season. • The Permian Gondwana coaly shales in Barapukuria basin, Bangladesh have wide range of HI from 20 to 204 mg HC/g TOC. • High influx of gymnosperm resinous OM, submerged/aquatic macrophytes, moss and algae in Permian peat-forming swamps. • Fla., Py, BePy and Bflas are relatively abundant PAHs in the Gondwana succession. • Small- to medium-scale wildfires occurred in the land area during Permian time. • The maturity of OM falls in the early to medium stages of oil generation. [ABSTRACT FROM AUTHOR]