Search Results (23)

Background: The PDX2 gene serves as a critical catalytic component in vitamin B6 (VB6) biosynthesis pathways and plays pivotal regulatory roles in plant growth. Methods: To investigate the metabolic regulation of PDX2 (GbPDX2) from Ginkgo biloba in VB6 biosynthesis during kernel development, we successfully cloned this gene and conducted systematic expression profiling through qRT-PCR across multiple tissues and developmental stages. Results: Bioinformatic characterization revealed that GbPDX2 contains a 765-bp coding sequence encoding a 254-amino acid polypeptide. The encoded protein displays typical hydrophilic properties (average hydrophobicity index: −0.32) and was predicted to be an unstable cytosolic protein (instability index: 45.7) lacking signal peptides or transmembrane domains with cytoplasmic localization. Phylogenetic analysis demonstrated that GbPDX2’s closest evolutionary relationship was with its ortholog in Picea sitchensis, which had an amino acid sequence similarity of 83.7% with spruce PsPDX2. Tissue-specific expression analysis revealed a gradient expression profile of Kernel > Exocarp > Leaves > Stems > Roots. The expression level in kernels was significantly higher than that in other tissues (19.7 times that in roots, 8.3 times that in stems, and 5.9 times that in leaves; p < 0.01), with peak transcript levels observed in mature kernels. HPLC quantification established a strong positive correlation between GbPDX2 expression dynamics and VB6 accumulation patterns during kernel maturation (r = 0.92, p < 0.01), and the peak period of VB6 reached 288.9 ± 7.1 μg/g. Conclusions: Our findings provide the first experimental evidence that GbPDX2 spatiotemporally regulates VB6 biosynthesis in ginkgo kernels, offering novel insights into the evolutionary adaptation of vitamin metabolism in gymnosperms. Full article

This study investigates the vibrational and acoustic properties of Sitka spruce (Picea sitchensis (Bong.) Carr.) and Indian rosewood (Dalbergia latifolia Roxb.), two common musical instrument woods, at moisture contents of 2%, 7%, and 12%. The specimens with dimensions of 400mm (longitudinal) × 25 mm (radial) × 10 mm (tangential) were tested under cantilever beam conditions using non-contact magnetic field excitation to generate sinusoidal and pulse signals. Vibration data were collected via acceleration sensors and FFT analyzers. The test method was based on ASTM D6874-12 standard. Results indicate that increasing moisture content reduces acoustic vibration characteristics, with hardwoods exhibiting higher declines than softwoods. From 2% to 12% moisture content, the first-order sound radiation quality factor of Sitka spruce and Indian rosewood decreased by 15.41% and 15.57%, respectively, while the sound conversion rate declined by 41.91% and 43.21%. Increased moisture content lowers first-order and second-order resonance frequencies, amplitude ratios, dynamic elastic modulus, vibration propagation velocity, acoustic radiation quality factor, and acoustic conversion efficiency, while increasing acoustic impedance and the loss factor. With excitation frequency increases from 100 Hz to 1500 Hz, vibration propagation velocity rises slightly, while the loss factor declines. Full article

We have sequenced the chloroplast genome of red spruce (Picea rubens) for the first time using the single-end, short-reads (44 bp) Illumina sequences, assembled and functionally annotated it, and identified simple sequence repeats (SSRs). The contigs were assembled using SOAPdenovo2 following the retrieval of chloroplast genome sequences using the black spruce (Picea mariana) chloroplast genome as the reference. The assembled genome length was 122,115 bp (gaps included). Comparatively, the P. rubens chloroplast genome reported here may be considered a near-complete draft. Global genome alignment and phylogenetic analysis based on the whole chloroplast genome sequences of Picea rubens and 10 other Picea species revealed high sequence synteny and conservation among 11 Picea species and phylogenetic relationships consistent with their known classical interrelationships and published molecular phylogeny. The P. rubens chloroplast genome sequence showed the highest similarity with that of P. mariana and the lowest with that of P. sitchensis. We have annotated 107 genes including 69 protein-coding genes, 28 tRNAs, 4 rRNAs, few pseudogenes, identified 42 SSRs, and successfully designed primers for 26 SSRs. Mononucleotide A/T repeats were the most common followed by dinucleotide AT repeats. A similar pattern of microsatellite repeats occurrence was found in the chloroplast genomes of 11 Picea species. Full article

One of the key areas in which the United Kingdom government plans to achieve net zero, reduce GHG emissions and sequester carbon is through afforestation. Afforestation will also provide ecosystem services to society. The Scottish government’s target is to increase woodland cover in Scotland to 25% by 2050. In this study, a land suitability analysis was used to investigate the likelihood of achieving this target based on the biophysically suitable and available land considering the current policy constraints for planting Sitka spruce (Picea sitchensis) in Scotland. The results showed that about 19% of land area in Scotland is biophysically suitable for Sitka spruce and about 13% is biophysically suitable and available based on policy constraints. Thus, there is an opportunity for the Scottish government to increase the woodland cover in Scotland to 31.5% and exceed its 25% woodland target. However, for Scotland to achieve net zero by 2045, it will require that more trees be planted on higher-quality agricultural land, different from areas where trees are currently planted. Full article

Metarhizium brunneum is a highly effective entomopathogenic fungus that also functions as a plant biostimulant. It can act as both an endophyte and rhizosphere colonizer; however, the mechanisms driving biostimulation are multifactorial. In this work, oilseed rape (Brassica napus) seeds were grown in composts treated with different concentrations of M. brunneum strains ARSEF 4556 or V275, or the M. brunneum-derived volatile organic compounds 1-octen-3-ol and 3-octanone. Biostimulation efficacy was found to be strongly dose dependent. Concentrations of 1 × 10⁶ conidia g⁻¹ compost were found to be most effective for the M. brunneum, whereas dosages of 1 µL 100 g⁻¹ compost were found to be efficacious for the volatiles. These optimized doses were assessed individually and in combined formulations with a hydrogel against oilseed rape (Brassica napus), sitka spruce (Picea sitchensis), maize (Zea mays) and strawberry (Fragaria annanassa). Both volatile compounds were highly effective biostimulants and were found to increase in biostimulatory efficiency when combined with M. brunneum conidia. Hydrogels were not found to interact with the growth process and may offer avenues for novel formulation technologies. This study demonstrates that Metarhizium-derived volatile organic compounds are actively involved in plant growth promotion and have potential for use in novel formulations to increase the growth of a wide range of commercially relevant crops. Full article

Picea sitchensis, Sitka spruce, is of interest to forestry as both a conservation species and a highly productive crop. Its native range stretches from Alaska to California, and it is hence distributed across a large environmental cline with areas of local adaptation. The IUFRO collection, established in 1968–1970, consists of 81 provenances of commercial and scientific interest spanning this native range. We used genotyping-by-sequencing on 1177 genotypes, originating from 80 of the IUFRO provenances which occupy 19 geographic regions of the Pacific Northwest, resulting in an SNP database of 36,567 markers. We detected low levels of genetic differentiation across this broad environmental cline, in agreement with other studies. However, we discovered island effects on geographically distant populations, such as those on Haida Gwaii and Kodiak Island. Using glaciation data, alongside this database, we see apparent post-glacial recolonization of the mainland from islands and the south of the range. Genotyping the IUFRO population expands upon the use of the collection in three ways: (i) providing information to breeders on genetic diversity which can be implemented into breeding programs, optimizing genetic gain for important traits; (ii) serving a scientific resource for studying spruce species; and (iii) utilizing provenances in breeding programs which are more tolerant to climate change. Full article

Terpene trilactones (TTLs) are the main secondary metabolites in Ginkgo biloba L. with efficacious pharmacological activity. Jasmonate ZIM-domain (JAZ) protein is a key regulatory factor of the JA signaling pathway, which regulates the biosynthesis of secondary metabolites such as terpenes, alkaloids, and flavonoids. In this study, GbJAZ01~GbJAZ11 were identified from the genome data in G. biloba, which contained TIFY-, Jas-, and weakly conserved NT-domains, and the promoters in most of them contained light, hormone, and stress-responsive elements. Phylogenetic analysis divided all JAZ proteins of Arabidopsis thaliana, Oryza sativa, Picea sitchensis, Taxus chinensis, and G. biloba into nine groups, in which GbJAZs belong to Group VI-IX. GbJAZs have similar functional motifs to A. thaliana and O. sativa, but also contain three specific motifs of gymnosperms, indicating that, although gymnosperms and angiosperms have some conservative structures and functions, their evolutionary processes are independent. Expression pattern analysis showed that the expression levels of GbJAZs were significantly up-regulated by MeJA, but the change pattern and amplitude were different, indicating that the function of GbJAZs in response to a JA signal may be different. After ABA and SA treatment, the expression of GbJAZs was up-regulated or inhibited in varying degrees, and different GbJAZs may be involved in the synergistic or antagonistic effects between JA and other hormone signals. The MeJA significantly increased the content of TTLs in G. biloba leaves, which were significantly positively correlated with the expression levels of GbJAZ01, 02, 07, and 11, and negatively correlated with the expression of GbJAZ04. They may play an important role in JA signaling pathways and the interactions between JA and other hormone signals, and participate in the regulation of the biosynthesis of TTLs. Our results provide a reference for the discovery that GbJAZs are involved in JA signaling pathways, and lay a theoretical foundation for analyzing JA signaling pathways to regulate the synthesis of secondary metabolites. Full article

Mitochondrial DNA (mtDNA), being maternally inherited in plants of the family Pinaceae, is an important source of phylogeographic information. However, its use is hindered by a low mutation rate and frequent structure rearrangements. In the present study, we tested the method of genomic libraries enrichment with mtDNA via the sequence capture method yielding mtDNA data which were further used to reconstruct the phylogenetic tree of the genus Abies. The baits for hybrid capture were obtained by long-range PCR using primers designed on the basis of the assembly of Abies sibirica Ledeb. mitochondrial genome. Mitochondrial genomes of Picea sitchensis (Bong.) Carr., Larix sibirica Ledeb., and Keteleeria davidiana (Bertrand) Beissn. were used as an outgroup. The resulting phylogenetic tree consists of two sister branches, including the Eurasian and American species, respectively, with some exceptions. The subclade of A. sachalinensis (F. Schmidt) Mast. and A. veitchii Lindl. (Japan and Sakhalin islands) occupies a basal position in the branch of American firs, probably due to the complex history of fir migrations from North America to Eurasia. The tree has high support for majority of clades. For species represented by more than one sample an intraspecific variability was found which is suitable to design mtDNA markers for phylogeographic and population studies. Full article

The Calluna vulgaris L. that dominated coastal heathlands of Western Europe were for millennia managed by regular burning cycles for improved grazing. Most places in Norway this practice has, however, been neglected over the last 5–7 decades, resulting in accumulation of above ground biomass including degenerated Calluna and successional fire-prone species, e.g., native juniper (Juniperus communis) and exotic blacklisted Sitka spruce (Picea sitchensis). Today, in dry periods, the heathland represents a fire threat to the increasing number of homes in the wildland–urban interface (WUI), as exemplified by the June 2021 Sotra Island WUI fire. The fire burned 700 ha of encroached heathlands, destroyed three buildings, and threatened settlements. In the present study, the Sotra fire was investigated to understand the fire development and analyse possible risk reducing measures. Photographic material obtained during the fire, weather conditions prior to and during the fire, involved fire fuel, fire spread mechanisms, firefighting response, and possible consequences under slightly changed circumstances were analysed. Compared to previous fires in coastal Norway, the Sotra fire represents a step change in fire development including, e.g., pyrocumulus-like clouds, fire whirls, and fire spread 270 m across a fjord. Preventive measures based on the local context are analysed, including engaging voluntary communities to remove fire-prone fuel, e.g., juniper and Sitka, to create defensible space. Moreover, strategic fire breaks in the terrain, e.g., well-managed heathland strengthening existing fuel breaks, e.g., lakes, cultivated fields, naked rock, and roads, are recommended. Mechanical cutting is suggested as a short-term measure while fenceless grazing may represent a long-term solution to prevent regrowth. During a period of record high energy prices, this may provide free of charge firewood and make way for future local food production, in line with the UN Sustainable Development Goals, while reducing the fire risk. Full article

Combining auxiliary variables and field inventory data of forest parameters using the model-based approach is frequently used to produce synthetic estimates for small areas. These small areas arise when it may not be financially feasible to take ground measurements or when such areas are inaccessible. Until recently, these estimates have been calculated without providing a measure of the variance when aggregating multiple pixel areas. This paper uses a Random Forest algorithm to produce estimates of quadratic mean diameter at breast height (QMDBH) (cm), basal area (m${}^2$ ha${}^{-1}$), stem density (n/ha${}^{-1}$), and volume (m${}^3$ ha${}^{-1}$), and subsequently estimates the variance of multiple pixel areas using a k-NN technique. The area of interest (AOI) is the state owned commercial forests in the Slieve Bloom mountains in the Republic of Ireland, where the main species are Sitka spruce (Picea sitchensis (Bong.) Carr.) and Lodgepole pine (Pinus contorta Dougl.). Field plots were measured in summer 2018 during which a lidar campaign was flown and Sentinel 2 satellite imagery captured, both of which were used as auxiliary variables. Root mean squared error (RMSE%) and R${}^2$ values for the modelled estimates of QMDBH, basal area, stem density, and volume were 19% (0.70), 22% (0.67), 28% (0.62), and 26% (0.77), respectively. An independent dataset of pre-harvest forest stands was used to validate the modelled estimates. A comparison of measured values versus modelled estimates was carried out for a range of area sizes with results showing that estimated values in areas less than 10–15 ha in size exhibit greater uncertainty. However, as the size of the area increased, the estimated values became increasingly analogous to the measured values for all parameters. The results of the variance estimation highlighted: (i) a greater value of k was needed for small areas compared to larger areas in order to obtain a similar relative standard deviation (RSD) and (ii) as the area increased in size, the RSD decreased, albeit not indefinitely. These results will allow forest managers to better understand how aspects of this variance estimation technique affect the accuracy of the uncertainty associated with parameter estimates. Utilising this information can provide forest managers with inventories of greater accuracy, therefore ensuring a more informed management decision. These results also add further weight to the applicability of the k-NN variance estimation technique in a range of forests landscapes. Full article

Stumps play a pivotal role in the epidemiology of the fungal forest pathogens Heterobasidion spp. because they are the main courts of primary airborne infections. The aims of this study were (i) to determine the susceptibility of seven tree species (i.e., Larix sibirica, Picea abies, Picea sitchensis, Pinus contorta, Pinus strobus, Pinus sylvestris and Pseudotsuga menziesii) to primary infection by H. annosum and H. parviporum through comparative inoculation experiments of conidia on wood discs in controlled conditions; (ii) to compare the susceptibility of wood discs of the same tree species to natural airborne infections in two Latvian Norway spruce forest stands infested either by H. annosum or H. parviporum; (iii) to explore the rates of infection of wood discs at increasing distances from spore sources in these two forests to make inferences on the range of spores dispersal. Results obtained by spraying wood discs with conidial suspensions in controlled conditions are in agreement with those obtained by exposing wood discs to the natural airborne inoculum in the forests, as clearly supported by the significant correlation (r = 0.79; p < 0.05) between the two sets of data. Susceptibility was highest in Pinus species, followed by P. abies and P. sitchensis. Susceptibility was lowest for L. sibirica and P. menziesii. The area colonized by Heterobasidion spp. in the sapwood of wood discs was much greater than that colonized in the heartwood. A sharp decrease in the rate of infection of wood discs with distance from spore sources (i.e., fruiting bodies) was observed, further confirming the importance of local spore sources in the epidemiology of Heterobasidion spp. Taken together, these findings could help designing tactics to manage these fungal forest pathogens. Full article

Non-indigenous conifers are considered invasive to the coastal dune heathland in Denmark, and massive clearing is carried out in an attempt to recreate and keep the original heathland. Burning is a common method for managing, but its feasibility to control the seed bank of conifers has not been investigated. This project shows that the burning of logged conifer trees will often eliminate seeds of lodgepole pine, mugo pine and Sitka spruce, even when the seeds were placed into a depth of five centimeters in the soil. The effect on seeds depends on the fuel load and the fire conditions (e.g., dryness, wind, and temperature). If the seeds were exposed to a high temperature, the seeds were not able to germinate afterward. The temperature was about 80 °C for all species. If the sum of temperatures based on temperature records every 30 s exceeded between 12,000 and 14,000 °C no seeds were able to germinate. The relationship between the mean temperature of the burns and the germination rate at seeds placed in various soil depths was modelled. Findings should be interpreted cautiously as each depth-species combinations were not replicated in space or time due to practical constraints. Full article

The use of cross-laminated timber (CLT), as an environmentally sustainable building material, has generated significant interest among the wood products industry, architects and policy makers in Washington State. However, the environmental impacts of CLT panels can vary significantly depending on material logistics and wood species mix. This study developed a regionally specific cradle-to-gate life cycle assessment of CLT produced in western Washington. Specifically, this study focused on transportation logistics, mill location, and relevant wood species mixes to provide a comparative analysis for CLT produced in the region. For this study, five sawmills (potential lamstock suppliers) in western Washington were selected along with two hypothetical CLT mills. The results show that the location of lumber suppliers, in reference to the CLT manufacturing facilities, and the wood species mix are important factors in determining the total environmental impacts of the CLT production. Additionally, changing wood species used for lumber from a heavier species such as Douglas-fir (Pseudotsuga menziesii) to a lighter species such as Sitka spruce (Picea sitchensis) could generate significant reduction in the global warming potential (GWP) of CLT. Given the size and location of the CLT manufacturing facilities, the mills can achieve up to 14% reduction in the overall GWP of the CLT panels by sourcing the lumber locally and using lighter wood species. Full article

To enrich the molecular data of Pinus bungeana Zucc. ex Endl. and study the regulating factors of different morphology controled by apical dominance. In this study, de novo assembly of transcriptome annotation was performed for two varieties of Pinus bungeana Zucc. ex Endl. that are obviously different in morphology. More than 147 million reads were produced, which were assembled into 88,092 unigenes. Based on a similarity search, 11,692 unigenes showed significant similarity to proteins from Picea sitchensis (Bong.) Carr. From this collection of unigenes, a large number of molecular markers were identified, including 2829 simple sequence repeats (SSRs). A total of 158 unigenes expressed differently between two varieties, including 98 up-regulated and 60 down-regulated unigenes. Furthermore, among the differently expressed genes (DEGs), five genes which may impact the plant morphology were further validated by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The five genes related to cytokinin oxidase/dehydrogenase (CKX), two-component response regulator ARR-A family (ARR-A), plant hormone signal transduction (AHP), and MADS-box transcription factors have a close relationship with apical dominance. This new dataset will be a useful resource for future genetic and genomic studies in Pinus bungeana Zucc. ex Endl. Full article

The development of medical applications exploiting the broad bioactivities of the diterpene therapeutic triptolide from Tripterygium wilfordii is limited by low extraction yields from the native plant. Furthermore, the extraordinarily high structural complexity prevents an economically attractive enantioselective total synthesis. An alternative production route of triptolide through engineered Saccharomyces cerevisiae (yeast) could provide a sustainable source of triptolide. A potential intermediate in the unknown biosynthetic route to triptolide is the diterpene dehydroabietic acid. Here, we report a biosynthetic route to dehydroabietic acid by transient expression of enzymes from T. wilfordii and Sitka spruce (Picea sitchensis) in Nicotiana benthamiana. The combination of diterpene synthases TwTPS9, TwTPS27, and cytochromes P450 PsCYP720B4 yielded dehydroabietic acid and a novel analog, tentatively identified as ‘miltiradienic acid’. This biosynthetic pathway was reassembled in a yeast strain engineered for increased yields of the pathway intermediates, the diterpene olefins miltiradiene and dehydroabietadiene. Introduction in that strain of PsCYP720B4 in combination with two alternative NADPH-dependent cytochrome P450 reductases resulted in scalable in vivo production of dehydroabietic acid and its analog from glucose. Approaching future elucidation of the remaining biosynthetic steps to triptolide, our findings may provide an independent platform for testing of additional recombinant candidate genes, and ultimately pave the way to biotechnological production of the high value diterpenoid therapeutic. Full article