Torreya Grandis Research Articles

Characterization of the complete plastome sequence of Torreya grandis var. jiulongshanensis (Taxaceae), a rare and endangered plant species endemic to Zhejiang province, China

Torreya grandis var. jiulongshanensis (Taxaceae) is an evergreen tree endemic to Zhejiang province, China, and it is listed as a rare plant species with extremely small populations. In our present study, we assembled the chloroplast (CP) genome of T. grandis var. jiulongshanensis using high-throughput sequencing data generated by an Illumina Hiseq X Ten platform. The results indicate that the complete CP genome is 136,705 bp in size with an overall guanine and cytosine content of 35.5%. The plastome has lost its quadripartite structure. In the CP genome, there are a total of 119 genes, including 82 protein-coding genes, 4 ribosomal RNA genes, and 33 transfer RNA genes. Phylogenetic analysis revealed that T. grandis var. jiulongshanensis is a sister species to T. grandis.

Comparative transcriptome analysis of the genes involved in lipid biosynthesis pathway and regulation of oil body formation in Torreya grandis kernels

Torreya grandis (T. grandis) is an important economic tree species because of the high content of unsaturated fatty acids in its kernel oil. However, different T. grandis landraces vary significantly in their fatty acid and oil contents, and their molecular regulatory mechanisms remain unclear. To investigate the molecular basis of the fatty acid biosynthesis pathway and oil body formation in T. grandis kernels, transcriptome sequencing were performed based on the Illumina platform in ten different T. grandis landraces. In total, 112,699 unigenes were identified, among them, 175 unigenes related to lipid biosynthesis were found, including 126 unigenes for fatty acid biosynthesis, 37 unigenes for triacylglycerol assembly and 12 unigenes for oil body proteins. The correlation analysis between the oil content and the expression levels of unigenes suggested that biotin carboxylase, acyl-ACP thioesterase A and lysophosphatidic acid acyltransferase may play key roles in oil accumulation. Three candidate genes (TgOLEO1, TgCLO1 and TgSLO1) encoding oil body-associated proteins were further identified through phylogenetic analysis and amino acid sequence alignment. Further subcellular localization assay indicated that all of the proteins were localized in both of endoplasmic reticulum and oil body. Compared with wild type, oil body proteins transiently over-expressed tobacco leaves had a higher abundance of oil bodies. Furthermore, the candidate regulatory genes (including TgWRI1, TgFUS3, etc.) that may be involved in the regulation of lipid biosynthesis were also identified. This study will be critical for the molecular assisted screening and breeding of high content of oil and unsaturated fatty acids cultivars for T. grandis.

Comparing environmental impacts of Chinese Torreya plantations and regular forests using remote sensing

It is important to evaluate the environmental impact of land-use change before deciding on its development because of possible problems in sustainability. The Chinese Torreya tree (Torreya grandis cv Merrillii) is a traditional nut tree cultivated in China for more than a thousand years. The income from the cultivation of this species has improved the local economy in southeastern China. To increase nuts production, large industrial plantations of Torreya are under construction, which require clear-cutting local subtropical evergreen forests. In this study, several biophysical indices from remote sensing data at a regular evergreen broadleaved forest and a nearby Torreya plantation were compared. The results indicated that the Torreya plantation had a significantly lower albedo (12.43 ± 0.15%) and higher soil water storage within surface 2-m layer (69.0 ± 2.24 kg/m2/month) than the regular forest (12.64 ± 0.14% and 57.87 ± 1.81 kg/m2/month). The annual average Normalized Difference Vegetation Index (NDVI) was significantly higher at the regular forest landscape than at the Torreya forest landscape. Except for NDVI, the resilience of these ecological processes was high in the regular evergreen broadleaved forest than in the Torreya plantation. The development of Torreya plantations at a large scale could alter local energy and hydrological processes. Environmental impacts and multiple ecological services should be considered for the sustainable development of Torreya plantations in this region. This study may provide an approach to evaluating potential environmental impacts for landscape change at large scales. Further research by ground observation and studies on ecological processes at different scales should be conducted. Our results may be helpful for relevant agencies to create strategies to better develop local economies and conserve the natural landscape.

Biochar mitigates the effect of nitrogen deposition on soil bacterial community composition and enzyme activities in a Torreya grandis orchard

Increased reactive N deposition has widespread effects on terrestrial ecosystems, such as biodiversity loss, soil acidification, as well as stimulated plant growth. Empirical studies show that biochar often affects soil quality, crop productivity, soil microbial community composition and enzyme activities. However, the effect of biochar addition on forest soil bacterial community along with enzyme activities under nitrogen (N) deposition and its related mechanisms have not been well studied yet. Therefore, a 2-year field study was conducted to investigate the effects of biochar amendment (0, 20, 40 kg biochar ha−1 yr−1) on soil nutrients, enzyme activities, and bacterial community in a Torreya grandis orchard under different levels of N deposition (0, 30, 60 kg N ha−1 yr−1). N deposition significantly increased soil nutrients availability, such as N, phosphorus (P) and potassium (K), while biochar amendment led to significant increase in soil pH, organic carbon (SOC), total N (TN), total P (TP), available P (AP) and available K (AK). Both N deposition and biochar amendment significantly decreased the soil microbial biomass carbon (MBC), altered soil microbial community and enzyme activities significantly. Biochar addition increased the relative abundance of phylum Proteobacteria under different levels of N deposition, but had variable effect on Acidobacteria groups. Non-metric multidimensional scaling (NMDS) indicated that biochar amendment can mitigate the effect of N deposition on soil bacterial community composition and enzyme activities. Soil pH and SOC played an important role in shaping soil bacterial community composition, while available AP and AK contents significantly related to the variation of soil enzyme activities. Structure equation modeling (SEM) revealed that N deposition had negative effect on soil enzyme activities while biochar amendment can mitigate this negative effect through increasing AP content. Our result suggests that biochar amendment can mitigate the alteration of soil bacterial community and enzyme activities induced by N deposition, and this mitigation effect was linked to the alteration of soil physicochemical properties, especially the increased AP content. Thus, biochar amendment could be a promising way to develop sustainable forest management under increasing N deposition.

Positional distribution of Δ5-olefinic acids in triacylglycerols from Torreya grandis seed oil: Isolation and purification of sciadonic acid

In recent years, in concern for human health, increasing attention was focused on sciadonic acid (SA), a unique Δ5-olefinic acid. Torreya grandis (T. grandis), a large, evergreen coniferous tree, whose seed yields rare and is known for a high level of SA. Triacylglycerols (TAGs) from the seeds of four different T. grandis varieties (Yuanfei, Xifei, Xiangyafei, and Zhimafei), were analyzed with respect to fatty acid profiles and positional distributions. The results indicated that SA represented the majority of the Δ5-olefinic acids in T. grandis seed oil. Irrespective of the variety, SA was naturally abundant at the sn-3 position of TAGs where they accounted for approximately 7.52%–12.00%. Based on this specific characteristic of Δ5-olefinic acids, T. grandis seed oil was subjected to a two-step enrichment process involving specific lipase-catalyzed ethanolysis and urea complexing. The content of SA in the fatty acid ethyl ester was increased to 80.14% from an initial value of 9.95%. These results suggested that the developed enrichment strategy was simple and effective in concentrating SA, and had the potential for commercial application.

The maintenance of stable yield and high genetic diversity in the agricultural heritage torreya tree system

BackgroundUnderstanding how traditional agriculture systems have been maintained would help design sustainable agriculture. In this study, we examined how farmers have used two types of local trees (Torreya grandis) for stable yield and maintaining genetic diversity in the “globally important agricultural heritage torreya tree system”. The two type of torreya trees are grafted torreya (GT) tree and non-grafted-torreya (NGT) tree. The GT tree has only female and was used to produced seed yields. The NGT tree has both male and female and was used to support GT tree by providing pollens and rootstocks. We first tested the ratio of GT tree to NGT tree, their age groups, ratio of female trees (including GT and NGT trees) to male, and the flowering period of GT and NGT trees. We then tested seed yields and genetic diversity of GT and NGT trees. We further tested gene flow among NGT trees, and the relationship of gene flow with exchange rates of pollens and seeds.ResultsGT and NGT trees (male and female) were planted in a mosaic pattern with a ratio of 4:1 (GT:NGT). In this planting pattern, one NGT male trees provided pollen for 20 female trees of GT and NGT. The trees were classified into four age groups (I = 100–400 years old; II = 400–700 years old; III = 700–1000 years old; and IV = 1000–1300 years old) based on basal diameter. The entire flowering period was longer for NGT trees than for GT trees that ensured GT trees (which lack of males) being exposed to pollens. GT tree had high and stable seed yield that increased with age groups. High genetic diversity has been maintained in both rootstocks of the GT trees and NGT trees. There was a strong gene flow among NGT trees, which positive correlated with the exchange rates of pollens and seeds.ConclusionsOur results suggest that farmers obtain stable seed yields, and maintain high genetic diversity by ingeniously using the local GT tree as yield producer and NGT tree as supporter. These GT and NGT trees together ensure sustainable torreya production.

Antioxidant, metabolic enzymes inhibitory ability of Torreya grandis kernels, and phytochemical profiling identified by HPLC-QTOF-MS/MS.

In this study, the antioxidant activities, α-glucosidase and tyrosinase inhibitory ability of Torreya grandis kernels (TGK) were performed. Samples were extracted with various polarity of ethanol, and the major phytochemical profile was characterized. The results showed that 70% of ethanol extract gave the richest phenolics and flavonoids. The strongest DPPH· and ABTS·+ scavenging ability, as well as the best inhibition on tyrosinase and α-glucosidase was also detected on 70% of ethanol extract. Among the fractions of 70% of ethanol extract, the ethyl acetate fraction (EAF) owned the highest phenolics, flavonoids, and the best DPPH· and ABTS·+ scavenging ability, and tyrosinase inhibition. Unexpectedly, the dichloromethane fraction possessed the strongest inhibition on α-glucosidase, which was much greater than that of acarbose. HPLC-QTOF-MS/MS analysis result to the characterization of 19 compounds from EAF. The results implied that TGK can be a potential source of natural antioxidants, α-glucosidase and tyrosinase inhibitors. Practical applications The kernels of T. grandis are one of the precious nuts in the world, and the extracts were advertised to show a variety of biological activities and pharmacological effects. However, researches on the phytochemical constituents and bioactivities are fewer. In this study, TGK was found to show good potency in antioxidant, α-glucosidase and tyrosinase inhibitory activities. The 70% ethanol is the best solvent for extracting above mentioned active components, and ethyl acetate can be the suitable enriching solvent. In addition, the predominant phytochemical compounds in EAF were characterized. Therefore, this research can help to the performance of further research and application of TGK in functional products.

Effects of nitrogen deposition and biochar amendment on soil respiration in a Torreya grandis orchard

Torreya grandis is an important economic nut tree species in southeastern China, but there is little information about its CO2 efflux under increasing atmospheric nitrogen (N) deposition. There are few studies that assess the response of soil respiration to biochar applications in orchard soils under N deposition conditions. We investigated changes in soil respiration rate and other environmental factors under a factorial combination of biochar amendment (BC0: 0 t ha−1, BC1: 20 t ha−1, BC2: 40 t ha−1) and simulated additional N deposition (N0: 0 kg N ha−1 yr−1, NL: 30 kg N ha−1 yr−1 and NH: 60 kg N ha−1 yr−1) treatments over three years (2016–2018). Soil respiration rate showed significant seasonal changes, with the highest rates occurring in summer and the lowest occurring in winter. The annual CO2 emission amount of the control was 3.1 ± 0.03 kg CO2 m−2. Nitrogen deposition significantly increased soil respiration, but the positive effects of high-N treatment decreased over time. Meanwhile, N deposition significantly decreased both the soil temperature sensitivity (Q10-soil) and air temperature sensitivity (Q10-air) of soil respiration. Biochar amendment significantly increased soil respiration in the first and third years. However, only BC2 reduced Q10-soil and Q10-air. The effects of biochar amendment on soil respiration varied with the level of N deposition. Three-factor analysis of variance showed that N deposition, biochar amendment, and time all had significant effects on soil respiration. Our results indicate that biochar could not effectively inhibit the promotion effect of N deposition on soil respiration in T. grandis orchard but may reduce soil carbon emission caused by future climate warming.

First report of Fomitiporia torreyae causing trunk rot on Chinese torreya (Torreya grandis) in Anhui Province of China

First report of Fomitiporia torreyae causing trunk rot on Chinese torreya (Torreya grandis) in Anhui Province of China

A unified DNA sequence and non-DNA sequence mapping model of complex traits.

Increasing evidence shows that quantitative inheritance is based on both DNA sequence and non-DNA sequence variants. However, how to simultaneously detect these variants from a mapping study has been unexplored, hampering our effort to illustrate the detailed genetic architecture of complex traits. We address this issue by developing a unified model of quantitative trait locus (QTL) mapping based on an open-pollinated design composed of randomly sampling maternal plants from a natural population and their half-sib seeds. This design forms a two-level hierarchical platform for a joint linkage-linkage disequilibrium analysis of population structure. The EM algorithm was implemented to estimate and test DNA sequence-based effects and non-DNA sequence-based effects of QTLs. We applied this model to analyze genetic mapping data from the OP design of a gymnosperm coniferous species, Torreya grandis, identifying 25 significant DNA sequence and non-DNA sequence QTLs for seedling height and diameter growth in different years. Results from computer simulation show that the unified model has good statistical properties and is powerful for QTL detection. Our model enables the tests of how a complex trait is affected differently by DNA-based effects and non-DNA sequence-based transgenerational effects, thus allowing a more comprehensive picture of genetic architecture to be charted and quantified.

Interaction of Biochar Amendment and Nitrogen Deposition on Soil Microbial Biomass Carbon and Enzyme Activity in a Torreya grandis Orchard

Interaction of Biochar Amendment and Nitrogen Deposition on Soil Microbial Biomass Carbon and Enzyme Activity in a Torreya grandis Orchard

A Case Study of Enhancing Sustainable Intensification of Chinese Torreya Forest in Zhuji of China

Chinese torreya (Torreya grandis cv. Merrillii) is an important cash tree in southeastern China and this species plays a major role in local economy. Establishing new plantations of Chinese torreya would be necessary in order to receive more economic benefit. However, expanding the area of torreya plantations would conflict with other land-use and also affect regional biodiversity. Under this context, local people and government made a paradigm shift from nuts productivity to sustainable practices. They explored the multi-functionalities of Chinese torreya forests, such as the social, cultural, environmental and health functionalities, and developed ecotourism as a breakthrough. The development of multi-functionalities of torreya plantations greatly improved the local economy and led a success in the local society. The strategy of this case completely followed the principles of sustainable intensification of agriculture and translational ecology, which involve scientists, stakeholders and policy makers to emphasize landscape multi-functionalities and minimize environmental impacts of operations. The knowledge from this study may be helpful to research in other regions.

Effects of Fertilization Measures on Soil Labile Organic Carbon and Nutrient of Old Torreya grandis

Effects of Fertilization Measures on Soil Labile Organic Carbon and Nutrient of Old Torreya grandis

New sights into lipid metabolism regulation by low temperature in harvested Torreya grandis nuts.

Torreya grandis, a large evergreen coniferous tree with oil-rich nuts, undergoes a crucial ripening stage after harvest that results in oil accumulation, finally giving rise to the nut that is edible in roasted form. To understand lipid metabolism in T. grandis nuts during the post-harvest ripening period, the effects of low temperature on lipid content, fatty acid composition, lipid biosynthesis and degradation were investigated. The lipid content increased during ripening at room temperature and a low temperature slowed down this increase. Linoleic acid content increased at low temperature, which was accompanied by an increase in the microsomal oleate desaturase (FAD2) activity and FAD2 expression. Furthermore, a low temperature attenuated lipid peroxidation as indicated by lower contents of malondialdehyde, hydroperoxide and total free fatty acid in T. grandis nuts during the ripening stage, as well as the down-regulation of gene expression of lipid degradation-related enzymes such as phospholipase D and lipoxygenases. The findings of the present study indicate that a low temperature increased polyunsaturated fatty acid contents by increasing FAD2 biosynthesis and decreasing lipid peroxidation, thereby improving the oil yield in T. grandis nuts during the post-harvest ripening period. © 2019 Society of Chemical Industry.

Interactive effects of drought and shading on Torreya grandis seedlings: physiological and growth responses

Moderate shading is optimal for the growth of Torreya grandis seedlings during drought. Light and water are two important environmental factors affecting tree seedling traits and regulating seedling survival and growth, but the effects of light on seedlings under drought remain poorly understood. The purpose of the present study was to examine the interactive effects of light and drought on second-year Torreya grandis seedlings. A pot experiment was conducted with 240 seedlings using four shading treatments (0%, 50%, 75%, and 90% reduction of full sunlight, respectively) and two watering treatments (well watered = 75% of field capacity, drought treatment = 30% of field capacity). In drought-treated seedlings, photosynthesis was inhibited along with decreased contents of chlorophyll and high contents of reactive oxygen, and biomass accumulation was reduced, as compared to well-watered seedlings. Seedlings grown under moderate shade (50% and 75%) showed highest biomass and photosynthetic rate both in well-watered and drought treatments. Similarly, the differences between well-watered and drought-treated seedlings for stress metabolism parameters (i.e., contents of proline and soluble protein) were also lower under moderate shading, indicating drought stress was alleviated by the shading. The chlorophyll contents and the photosynthetic rate were higher in the seedlings under moderate shading than in those in full sunlight, contributing to a higher biomass in the former. These results suggest that moderate shading can effectively prevent stress caused to the Torreya grandis seedlings by excess light and can also alleviate the damage caused to them by drought.

Comparative transcriptome analysis reveals key genes in the regulation of squalene and β-sitosterol biosynthesis in Torreya grandis

Torreya grandis (T. grandis, Taxaceae) is both economically and medicinally valuable species being rich in various bioactive compounds (e.g., squalene and β-sitosterol). However, the contents of these compounds are various and cultivar specific, and the complicated regulatory mechanisms of their biosynthesis in T. grandis are still unknown. To uncover the underlying molecular mechanisms that control the differences in the accumulation of squalene and β-sitosterol, a comprehensive transcriptome was constructed from nine different T. grandis cultivars. A total of more than 60,372 unigenes were obtained, of which over 60% were successfully annotated. Identification and expression analysis of the differentially-expressed genes (DEGs) showed that 39 candidate genes were involved in squalene and β-sitosterol biosynthesis in T. grandis seeds. In particular, the expression patterns of genes related to the mevalonate (MVA) and methylerythritol phosphate (MEP) pathways indicates that both pathways promote the upstream biosynthesis of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) in different T. grandis cultivars. Moreover, several key regulatory steps controlling the differential accumulation of squalene and β-sitosterol between T. grandis cultivars were also discussed.

Pyrolysis molecule of Torreya grandis bark for potential biomedicine.

Torreya grandis is a unique tree species in China. Although full use has been made of the timber, the processing and utilization of the bark has not been effective. In order to explore a new way to utilize the bark of Torreya grandis, a powder of T. grandis bark was prepared and analyzed qualitatively and quantitatively. Differential scanning calorimetry (TG) and pyrolysis gas chromatography-mass spectrometry (PY-GC/MS) revealed many bioactive components in the bark of T. grandis, such as acetic acid, 2-methoxy-4-vinyl phenol, D-mannose, and furfural. These substances have potential broad applications in the chemical industry, biomedicine, and food additives. The chemical constituents of the bark of T. grandis suggest a theoretical basis for the future development and utilization of the bark of T. grandis.

The antioxidant and tyrosinase inhibition properties of essential oil from the peel of Chinese Torreya grandis Fort.

The antioxidant and tyrosinase inhibition properties of essential oil from the peel of Chinese Torreya grandis Fort. (CTGF oil) were investigated. The antioxidant properties of CTGF oil were evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging tests, and it showed an IC50 value of 0.88 ± 0.06 μg mL−1 compared to VC with a value of 1.0 ± 0.1 μg mL−1 and BHT with a value of 2.9 ± 0.1 μg mL−1. CTGF oil had relatively significant DPPH scavenging activity (p < 0.05), which could be compared to other natural oils as follows: cassia oil (92.4%) > peppermint oil (89.1%) > clove leaf oil (87.7%) > nutmeg oil (80.1%) > CTGF oil (42.6%) > lemon oil (25.5%). Furthermore, changes in the peroxide values of different treatment groups during storage for 60 days were estimated. CTGF oil displayed better antioxidant activity than lemon oil, with activity similar to that of BHT for the reduction of the peroxide value. Moreover, CTGF oil effectively inhibited the oxidation of 3,4-dihydroxy-l-phenylalanine (l-DOPA) through tyrosinase (P < 0.05). The essential oil obtained after hydrodistillation from the peel of Chinese Torreya grandis Fort. could be potentially utilized as a good new alternative source of natural antioxidants for the food and cosmetics industries.

A Random Forest-Based Approach to Map Soil Erosion Risk Distribution in Hickory Plantations in Western Zhejiang Province, China

Increasing agroforestry areas with improper management has produced serious environmental problems, such as soil erosion. It is necessary to rapidly predict the spatial distribution of such erosion risks in a large area, but there is a lack of approaches that are suitable for mountainous regions. The objective of this research was to develop an approach that can effectively employ remotely-sensed and ancillary data, to map soil erosion risks in an agroforestry ecosystem in a mountainous region. This research employed field survey data, soil-type maps, digital elevation model data, weather station data, and Landsat imagery, for extraction of potential variables. It used the random forest approach to identify eight key variables—slope, slope of slope, normalized difference greenness index at leaf-on season, soil organic matter, fractional vegetation at leaf-on season, fractional soil at leaf-off season, precipitation in June, and percent of soil clay—for mapping soil erosion risk distribution in hickory plantations in Western Zhejiang Province, China. The results showed that an overall accuracy of 89.8% was obtained for three levels of soil erosion risk. Approximately one-fourth of hickory plantations were at high-risk, requiring the owners or decision makers to take proper measures to reduce the soil erosion problem. This research provides a new approach to predict soil erosion risk, based on the primary variables that can be extracted directly from remotely-sensed data and ancillary data. This proposed approach will be valuable for other agroforestry and plantations, such as Torreya grandis, eucalyptus, and the rubber tree, that are playing important roles in improving economic conditions for the local farmers but face soil erosion problems.

Change in microbial communities, soil enzyme and metabolic activity in a Torreya grandis plantation in response to root rot disease

Soil microorganisms have a profound influence on plant growth, but as well on plant disease. It is still not clear, however, how microbial community structures and functional activities are changing in transitions between healthy and diseased soils. We performed detailed bacterial and fungal community analysis in healthy and root-rot diseased soils of Torreya grandis plantation forest in the subtropical region of China. Soil enzyme activities and microbial metabolic profiling was done to find their interactions with the diseased plants and the microbial functioning. The diseased trees showed lower root biomass, total chlorophyll and N contents in leaf, but higher peroxidase activity. The soils under diseased trees had lower soil organic carbon (SOC) content, but higher pH, moisture and available N content. The microbial diversity was unchanged between the healthy and diseased soils, but the diseased soils had lower 16S rRNA and ITS gene copy numbers. Illumina MiSeq sequencing showed that the fungal rather than the bacterial community composition differed significantly (P < 0.05) and Gibberella and Cryptococcus were associated with the diseased trees. The activities of β-D-cellobiosidase, β-glucosidase and peroxidase and microbial carbohydrate utilization rates were typically enhanced in the diseased soils. Changes in SOC, available N and soil moisture associated to root-rot disease were key factors shaping microbial community composition and activity, and closely linked to plant biomass. Our study showed that prolonged root-rot infestation decreased tree vitality and soil microbial biomass, changed fungal community composition and soil functioning towards a faster organic C decomposition, which potentially may increase soil organic matter turnover.