Intermediate complex morphophysiological dormancy in seeds of Aconitum barbatum (Ranunculaceae).

BACKGROUND: Seed dormancy and germination are key components of plant regeneration strategies. Aconitum barbatum is a plant commonly found in northeast China. Although it has potential for use in gardening and landscaping, its seed dormancy and regeneration strategy, which adapt to its natural habitat, are not well understood. Our aim was to identify conditions for breaking A. barbatum seed dormancy and determine its dormancy type. Embryo growth and germination were determined by collecting seeds over time in the field. Laboratory experiments that control light, temperature, and stratification period were conducted to assess dormancy breaking and germination, and GA3 was used to identify dormancy type. RESULTS: Seeds of A. barbatum have undeveloped embryos with physiological dormancy at maturity in autumn. The embryo-to-seed length ratio increases from 0.33 to 0.78 before the emergence of the radical. Under natural environmental conditions, embryo development begins in early winter. Laboratory experiments have shown that long-term incubation under 4 °C (cold stratification) promotes embryo development and seed dormancy break. With an extension of cold stratification, an increase in germination percentages was observed when seeds were transferred from 4 °C to warmer temperatures. Seeds exposed to light during incubation show a higher germination percentage than those kept in the dark. Seed germination can also be enhanced by a 100 mg/L GA3 concentration. CONCLUSIONS: Seeds of A. barbatum display intermediate complex morphophysiological dormancy at maturity. In addition to the underdeveloped embryo, there are also physiological barriers that prevent the embryo from germinating. Dormancy breaking of A. barbatum seeds can be achieved by natural winter cold stratification, allowing seeds to germinate and sprout seedlings at the beginning of the following growing season. Our findings provide valuable insights into the seed dormancy and regeneration strategy of A. barbatum, which could facilitate its effective utilization in gardening and landscaping.

Identification of genes associated with the biosynthesis of unsaturated fatty acid and oil accumulation in herbaceous peony 'Hangshao' (Paeonia lactiflora 'Hangshao') seeds based on transcriptome analysis.

BACKGROUND: Paeonia lactiflora 'Hangshao' is widely cultivated in China as a traditional Chinese medicine 'Radix Paeoniae Alba'. Due to the abundant unsaturated fatty acids in its seed, it can also be regarded as a new oilseed plant. However, the process of the biosynthesis of unsaturated fatty acids in it has remained unknown. Therefore, transcriptome analysis is helpful to better understand the underlying molecular mechanisms. RESULTS: Five main fatty acids were detected, including stearic acid, palmitic acid, oleic acid, linoleic acid and α-linolenic acid, and their absolute contents first increased and then decreased during seed development. A total of 150,156 unigenes were obtained by transcriptome sequencing. There were 15,005 unigenes annotated in the seven functional databases, including NR, NT, GO, KOG, KEGG, Swiss-Prot and InterPro. Based on the KEGG database, 1766 unigenes were annotated in the lipid metabolism. There were 4635, 12,304, and 18,291 DEGs in Group I (60 vs 30 DAF), Group II (90 vs 60 DAF) and Group III (90 vs 30 DAF), respectively. A total of 1480 DEGs were detected in the intersection of the three groups. In 14 KEGG pathways of lipid metabolism, 503 DEGs were found, belonging to 111 enzymes. We screened out 123 DEGs involved in fatty acid biosynthesis (39 DEGs), fatty acid elongation (33 DEGs), biosynthesis of unsaturated fatty acid (24 DEGs), TAG assembly (17 DEGs) and lipid storage (10 DEGs). Furthermore, qRT-PCR was used to analyze the expression patterns of 16 genes, including BBCP, BC, MCAT, KASIII, KASII, FATA, FATB, KCR, SAD, FAD2, FAD3, FAD7, GPAT, DGAT, OLE and CLO, most of which showed the highest expression at 45 DAF, except for DGAT, OLE and CLO, which showed the highest expression at 75 DAF. CONCLUSIONS: We predicted that MCAT, KASIII, FATA, SAD, FAD2, FAD3, DGAT and OLE were the key genes in the unsaturated fatty acid biosynthesis and oil accumulation in herbaceous peony seed. This study provides the first comprehensive genomic resources characterizing herbaceous peony seed gene expression at the transcriptional level. These data lay the foundation for elucidating the molecular mechanisms of fatty acid biosynthesis and oil accumulation for herbaceous peony.

Seed development in Paeonia ostii (Paeoniaceae), with particular reference to embryogeny.

BACKGROUND: Seeds of Paeonia ostii have been proposed as a source of raw material for the production of edible oil; however, lack of information about the developmental biology of the seeds hampers our ability to use them. Our aim was to investigate development of the seed coat, endosperm and embryo of P. ostii in relation to timing of accumulation of nutrient reserves from pollination to seed maturity. Ovules and developing seeds of P. ostii were collected at various stages of development from zygote to maturity. Seed fresh mass, dry mass, germination, moisture, soluble sugars, starch, protein and oil content were determined. Ontogeny of seeds including embryo, endosperm and seed coat were analyzed histologically. RESULTS: The ovule of P. ostii is anatropous, crassinucellate and bitegmic. The zygote begins to divide at about 5 days after pollination (DAP), and the division is not accompanied by cell wall formation. By 25 DAP, the proembryo begins to cellularize. Thereafter, several embryo primordia appear at the surface of the cellularized proembryo, but only one matures. Endosperm development follows the typical nuclear type. The seed coat is derived from the outer integument. During seed development, soluble sugars, starch and crude fat content increased and then decreased, with maximum contents at 60, 80 and 100 DAP, respectively. Protein content was relatively low compared with soluble sugars and crude fat, but it increased throughout seed development. CONCLUSIONS: During seed development in P. ostii, the seed coat acts as a temporary storage tissue. Embryo development of P. ostii can be divided into two stages: a coenocytic proembryo from zygote (n + n) that degenerates and a somatic embryo from peripheral cells of the proembryo (2n → 2n). This pattern of embryogeny differs from that of all other angiosperms, but it is similar to that of gymnosperms.

Impacts of Local Effects and Surface Loads on the Common Mode Error Filtering in Continuous GPS Measurements in the Northwest of Yunnan Province, China.

While seasonal hydrological mass loading, derived from Gravity Recovery and Climate Experiment (GRACE) measurements, shows coherent spatial patterns and is an important source for the common mode error (CME) in continuous global positioning system (cGPS) measurements in Yunnan, it is a challenge to quantify local effects and detailed changes in daily GPS measurements by using GRACE data due to its low time and spatial resolutions. In this study, we computed and compared two groups of CMEs for nine cGPS sites in the northwest Yunnan province; rCMEs were computed with the residual cGPS time series having high inter-station correlations, while oCMEs were computed with all the GPS time series. The rCMEs-filtered time series had smaller variances and larger root mean square (RMS) reductions than those that were oCMEs-filtered, and when the stations local effects were not removed, spurious transient-like signals occurred. Compared with hydrological mass loading (HYDL), its combination with non-tidal atmosphere pressure and ocean mass reached a better agreement with the CME in the vertical component, with the Nash-Sutcliffe efficiency (NSE) increasing from 0.28 to 0.55 and the RMS reduction increasing from 15.19% to 33.4%, respectively. Our results suggest that it is necessary to evaluate the inter-station correlation and remove the possible noisy stations before conducting CME filtering, and that one should carefully choose surface loading models to correct the raw cGPS time series if CME filtering is not conducted.

A review of the seed biology of Paeonia species (Paeoniaceae), with particular reference to dormancy and germination.

MAIN CONCLUSION: Most Paeonia species have epicotyl dormancy. Germination of peony seeds requires warm stratification for embryo growth and radicle protrusion followed by cold stratification for epicotyl growth. The genus Paeonia (Paeoniaceae) includes many popular ornamentals, has colorful flowers and contains several Chinese medicinal species. The germination protocol for seeds of Paeonia species is complex and impedes the breeding of new cultivars and contributes to the rarity and high cost of the plants. Although numerous reports on seed dormancy/germination in peonies are scattered throughout the literature, most of them are in Chinese. The primary aims of this paper are to provide a general overview of the available information on seed dormancy/germination in peonies and to make some suggestions regarding propagation for the peony industry and breeders. Most Paeonia species have epicotyl dormancy. The embryo is differentiated into organs, but it is underdeveloped (small) and must grow inside the seed before the radicle can emerge. Germination of peony seeds requires warm stratification for embryo growth and radicle protrusion followed by cold stratification for epicotyl growth. In addition, the epicotyl is sensitive to cold stratification only after the root has grown to a certain length. GA3 treatment enhances embryo growth and subsequent germination percentages. Further investigations on the physiology, genetics and proteomics would contribute to a better understanding of seed dormancy in Paeonia.

Lack of divergence in seed ecology of two Amphicarpaea (Fabaceae) species disjunct between eastern Asia and eastern North America.

PREMISE OF THE STUDY: Many congeneric species are disjunct between eastern Asia and eastern North America. No previous study has compared the seed biology of closely related disjunct taxa of legumes or of a diaspore-heteromorphic species. Our objective was to compare seed dormancy in two such sister species in the genus Amphicarpaea (Fabaceae). METHODS: We investigated the ecology and ecophysiology of aerial and subterranean seeds of the amphicarpic species Amphicarpaea edgeworthii from China and compared the results to those published for its sister species A. bracteata from eastern North America. KEY RESULTS: The seed coat of aerial seeds of A. edgeworthii is well developed, whereas the seed coat of subterranean seeds is not. Aerial seeds have combinational dormancy (physical dormancy [PY] + physiological dormancy [PD]) broken by scarification followed by cold stratification or by after-ripening and scarification; whereas subterranean seeds have PD broken by cold stratification. Aerial seeds formed a persistent soil seed bank, and subterranean seeds a transient soil seed bank. Aerial seeds of A. bracteata also have PY+PD and subterranean seeds PD. Subterranean seeds of both species are desiccation intolerant. CONCLUSION: Dormancy in neither aerial nor subterranean seeds of both species has diverged over geological time. Compared to subterranean seeds, aerial seeds of both species dispersed over longer distances. Seed dispersal ability and degree of dormancy of neither species fits the high-risk/low-risk (H-H/L-L) strategy found in many diaspore-dimorphic species. Rather, both species have an H-L/L-H strategy for these two life history traits.

A pilot trial of neoadjuvant pyrotinib plus trastuzumab, dalpiciclib, and letrozole for triple-positive breast cancer.

Triple-positive breast cancer (TPBC) poorly responds to current standard neoadjuvant therapy (trastuzumab plus pertuzumab and chemotherapy). Our previous MUKDEN 01 study showed a promising total pathological complete response (tpCR) rate of 30.4% with neoadjuvant pyrotinib (pan-human epidermal growth factor receptor tyrosine kinase inhibitor) plus dalpiciclib (cyclin-dependent kinase 4/6 inhibitor) and letrozole, but the efficacy remains suboptimal. This pilot study (NCT05228951) explored adding trastuzumab to this triplet neoadjuvant regimen in patients with stage II-III TPBC. The primary endpoint was tpCR (ypT0/is, ypN0) rate. Between February 2022 and June 2022, 12 patients were enrolled, and seven (58%; 95% confidence interval [CI], 27.7%-84.8%) patients achieved tpCR. The rate of residual cancer burden (RCB) 0-I was 75% (95% CI, 46.8%-91.1%). The objective response rate (ORR) was 92% (95% CI, 64.6%-98.5%). Mean Ki-67 level was significantly reduced from 45.0% (95% CI, 19.5%-70.5%) at baseline to 17.2% (95% CI, 0.7%-33.7%) after neoadjuvant therapy (p = 0.03). The most common grade 3 adverse events were diarrhea (four [33%]) and decreased neutrophil count (three [25%]). No grade 4 adverse events or treatment-related deaths occurred. This four-drug neoadjuvant regimen shows promising pathological response with an acceptable safety profile in patients with TPBC. A randomized controlled trial (NCT05638594) of this regimen is being conducted.

Assessment of the capability of cadmium accumulation and translocation among 31 willows: four patterns of willow biomass variation response to cadmium.

Cadmium (Cd) pollution threatens food security and the environment. Willow species (Salix, Salicaceae) exhibit a remarkable potential to restore Cd-polluted sites due to their high biomass production and high Cd accumulation capacities. This study examined the Cd accumulation and tolerance in 31 genotypes of shrub willow in hydroponic conditions at varying Cd levels (0 µM Cd, 5 µM Cd, and 20 µM Cd). The root, stem, and leaf biomass of 31 shrub willow genotypes showed significant differences to Cd exposure. Among 31 willow genotypes, four patterns of biomass variation response to Cd were identified: insensitive to Cd; growth inhibition due to excessive Cd supply (high Cd inhibition); low Cd causing inhibited growth, whereas high Cd leading to increased biomass (U-shape); and growth increment with excessive Cd exposure (high Cd induction). The genotypes belonging to the "insensitive to Cd" and/or "high Cd induction" were candidates for the utilization of phytoremediation. Based on the analysis of Cd accumulation of 31 shrub willow genotypes at high and low Cd levels, genotypes 2372, 51-3, and 1052 obtained from a cross between S. albertii and S. argyracea grew well and accumulated relatively more Cd levels than other genotypes. In addition, for Cd-treated seedlings, root Cd accumulation was positively correlated with shoot Cd accumulation and total Cd uptake, demonstrating that Cd accumulation in roots could serve as a biomarker for evaluating the Cd extraction capacity of willows, especially in hydroponics screening. The results of this study screened out willow genotypes with high Cd uptake and translocation capacities, which will provide valuable approaches for restoring Cd-contaminated soils with willows.

Effects of neoadjuvant stereotactic body radiotherapy plus adebrelimab and chemotherapy for triple-negative breast cancer: A pilot study.

Background: Emerging data have supported the immunostimulatory role of radiotherapy, which could exert a synergistic effect with immune checkpoint inhibitors (ICIs). With proven effective but suboptimal effect of ICI and chemotherapy in triple-negative breast cancer (TNBC), we designed a pilot study to explore the efficacy and safety of neoadjuvant stereotactic body radiotherapy (SBRT) plus adebrelimab and chemotherapy in TNBC patients. Methods: Treatment-naïve TNBC patients received two cycles of intravenous adebrelimab (20 mg/kg, every 3 weeks), and SBRT (24 Gy/3 f, every other day) started at the second cycle, then followed by six cycles of adebrelimab plus nab-paclitaxel (125 mg/m² on days 1 and 8) and carboplatin (area under the curve 6 mg/mL per min on day 1) every 3 weeks. The surgery was performed within 3-5 weeks after the end of neoadjuvant therapy. Primary endpoint was pathological complete response (pCR, ypT0/is ypN0). Secondary endpoints included objective response rate (ORR), residual cancer burden (RCB) 0-I, and safety. Results: 13 patients were enrolled and received at least one dose of therapy. 10 (76.9%) patients completed SBRT and were included in efficacy analysis. 90% (9/10) of patients achieved pCR, both RCB 0-I and ORR reached 100% with three patients achieved complete remission. Adverse events (AEs) of all-grade and grade 3-4 occurred in 92.3% and 53.8%, respectively. One (7.7%) patient had treatment-related serious AEs. No radiation-related dermatitis or death occurred. Conclusions: Adding SBRT to adebrelimab and neoadjuvant chemotherapy led to a substantial proportion of pCR with acceptable toxicities, supporting further exploration of this combination in TNBC patients. Funding: None. Clinical trial number: NCT05132790.

[Application of AO miniplate and screw in the treatment of metacarpophalangeal joint periarticular fractures].

OBJECTIVE: To evaluate the clinical efficacies for open reduction and internal fixation of unstable periarticular fractures of metacarpophalangeal joint (MCP) with the AO miniature plate system. METHODS: A total of 265 patients (172 males and 93 females) with 302 MCP periarticular fractures were retrospectively reviewed. Their mean age was 32.5 years old (range: 17 - 59). The standard internal fixation treatment method was established on the basis of the AO/ASIF Comprehensive Classification of Fractures. A "T" shape plate, double-row-plate or a condylar plate was used for A2, A3, C1, C2 type fractures. Screws alone were used for B type fractures. Active and passive flexion and extension exercises at Day 3 post-operation within the limits of patient pain tolerance. All patients were evaluated regarding the total active motion (TAM) score, average PROM, quick-DASH score, the power of gripping, pinching and Kapandji score. RESULTS: The patients were followed up for an average of 4.6 months (range: 4 - 24). Radiological examinations showed that the fracture line disappeared in an average of 8.2 weeks (average: 8.2). According to TAM rating criteria, the functions of hands were as follows: excellent (n = 113), good (n = 136) and poor (n = 53). The fair rate was 82.8%. The average PROM of MP joint was 82.3° ± 4.7° and the average quick-DASH score 17.4. Contrast to the health side, the power of gripping recovered for 94.5% and pinching for 88.6%. The Kapandji score was 90%. A total of 103 MCP (34.1%) completely recovered. Contrasting between the head of metacarpal fracture combined the base of proximal phalangeal fracture and alone the head of metacarpal fracture or the base of proximal phalangeal fracture, the post-operative rates of complications and tendon adhesion were higher. As compared with traditional methods, each of the above parameters had statistic significances (P < 0.01). CONCLUSION: Because of complex anatomic structures, the MCP periarticular fractures have such complications as tendon adhesion, joint stiffness and post-traumatic arthritis, etc. The traditional treatment method is less effective. The AO miniplate and screw system provides rigid and stable fixation so that it is a preferred technique in the treatment of MCP periarticular fractures.

LncRNA OIP5-AS1 Mitigates Bupivacaine-Induced Neurotoxicity in Dorsal Root Ganglion Neurons Through Regulating NFAT5 Expression via Sponging miR-34b.

Bupivacaine (BUP), which is widely used in anesthesia, can cause neurotoxicity and neurological abnormalities. This work intended to study the function of long non-coding RNA (lncRNA) OIP5 antisense RNA 1 (OIP5-AS1) in BUP-triggered neurotoxicity. OIP5-AS1, microRNA (miR)-34b, and nuclear factor of activated T cells 5 (NFAT5) levels were examined via real-time quantitative PCR (RT-qPCR). Cell proliferation, caspase-3 activity, and apoptosis were assessed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), caspase-3 activity, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays. The regulatory relationships between miR-34b and OIP5-AS1 or NFAT5 were validated via RNA binding protein immunoprecipitation (RIP) and dual-luciferase reporter assays. Our data demonstrated that OIP5-AS1 and NFAT5 levels were downregulated and miR-34b was upregulated upon exposure to BUP. Functional assays implied that the OIP5-AS1 deficiency impeded cell proliferation and enhanced the apoptosis of DRG neurons, while OIP5-AS1 addition reversed these changes. Moreover, OIP5-AS1 could bind to miR-34b and OIP5-AS1 regulated BUP-induced neurotoxicity via miR-34b. Besides, miR-34b could directly interact with NFAT5. Augmentation of miR-34b impeded cell proliferation and expedited the apoptosis and caspase-3 activity, while NFAT5 addition neutralized these impacts. Finally, it was verified that OIP5-AS1 could upregulate NFAT5 through sponging miR-34b. In sum, our results disclosed that OIP5-AS1 ameliorated BUP-caused neurotoxicity via regulating the miR-34b/NFAT5 axis, suggesting that OIP5-AS1 might be a promising therapeutic target for the treatment of BUP-induced neurotoxicity.

Deterioration of orthodox seeds during ageing: Influencing factors, physiological alterations and the role of reactive oxygen species.

Seed viability is an important trait in agriculture which directly influences seedling emergence and crop yield. However, even when stored under optimal conditions, all seeds will eventually lose their viability. Our primary aims were to describe factors influencing seed deterioration, determine the morphological, physiological, and biochemical changes that occur during the process of seed ageing, and explore the mechanisms involved in seed deterioration. High relative humidity and high temperature are two factors that accelerate seed deterioration. As seeds age, frequently observed changes include membrane damage and the destruction of organelle structure, an increase in the loss of seed leachate, decreases of respiratory rates and ATP production, and a loss of enzymatic activity. These phenomena could be inter-related and reflect the general breakdown in cellular organization. Many processes can result in seed ageing; it is likely that oxidative damage caused by free radicals and reactive oxygen species (ROS) is primarily responsible. ROS can have vital interactions with any macromolecule of biological interest that result in damage to various cellular components caused by protein damage, lipid peroxidation, chromosomal abnormalities, and DNA lesions. Further, ROS may also cause programmed cell death by inducing the opening of mitochondrial permeability transition pores and the release of cytochrome C. Some repairs can occur in the early stages of imbibition, but repair processes fail if sufficient damage has been caused to critical functional components. As a result, a given seed will lose its viability and eventually fail to germinate in a relatively short time period.

Concise synthesis of α-cyano tetrahydroisoquinolines with a quaternary center via Strecker reaction.

A concise synthesis of α-cyano tetrahydroisoquinolines with a quaternary center via the Strecker reaction was successfully realized by employing TMSCN as cyano source and KF as fluoride source, furnishing the products with up to 99% yield. An isomerization of α-cyano tetrahydroisoquinoline was observed under alkaline conditions to give the isomer via [1,3]-H shift.

A review of the research progress in T-lymphocyte immunity and cervical cancer.

Cervical cancer develops as a result of T-cell immune evasion by human papillomavirus (HPV). T-cell immunity requires the participation of many factors, such as antigen-presenting cells (APCs), cytokines, co-stimulatory molecules, etc. HPV vaccines are promising treatments to prevent HPV infection and cervical cancer. This article mainly provides a summary of the number and function changes of T cells during HPV infection and cervical cancer development. Studies on t-cell immunotherapy, which is expected to become a new treatment for cervical cancer after surgery, radiotherapy, and chemotherapy, are also reviewed in this article.

Seed Biology of Lepidium apetalum (Brassicaceae), with Particular Reference to Dormancy and Mucilage Development.

Lepidium apetalum (Brassicaceae) is an annual or biennial weed widely distributed in Asia and Europe. The outer surface of L. apetalum seeds produces a large amount of mucilage. The primary aim of this study was to explore the dormancy characteristics and to determine how mucilage develops. The role of mucilage in water absorption/dehydration, the effects of after-ripening, gibberellin acid (GA3), cold stratification and seed coat scarification on germination, the role of mucilage in germination and seedling growth during drought, and the progress of mucilage production during seed development were investigated. The results indicate that the best temperature regime for germination was 10/20 °C. After-ripening, GA3 and seed coat scarification helped to break dormancy. Light promoted germination. Seedling growth of mucilaged seeds were significantly higher than those of demucilaged seeds at -0.606 and -1.027 MPa. Anatomical changes during seed development showed that mucilage was derived from the outer layer of the outer integument cells. Our findings suggest that seeds of L. apetalum exhibited non-deep physiological dormancy. The dormancy characteristics along with mucilage production give seeds of L. apetalum a competitive advantage over other species, and thus contribute to its potential as a weed. Effective control of this weed can be achieved by deep tillage.

A randomized clinical study of the treatment of white lesions of the vulva with a fractional ultrapulsed CO2 laser.

BACKGROUND: White lesions of the vulva are a common vulvar disease of unclear etiology. Although a variety of treatments have been used to treat the disease in clinical practice, there is currently a lack of effective radical therapies. This study aimed to compare the feasibility and effectiveness of fractional ultrapulsed CO2 laser with that of high-intensity focused ultrasound in the treatment of white lesions of the vulva. METHODS: A total of 60 patients with pruritus vulvae who were treated at the Center for Diagnosis and Treatment of Cervical Diseases in our hospital between December, 2017, and December 2018 were enrolled in this study. The possibility of malignant lesions of the vulva was ruled out by histopathological diagnosis following colposcopic biopsy. The patients were randomly divided into two groups: a laser treatment group (group L, n=30) and a focused ultrasound treatment group (group U, n=30). The patients were monitored for changes in signs and symptoms during and after treatment, and the treatment outcomes of the two groups were compared. RESULTS: The local symptoms of pruritus were alleviated by both the fractional ultrapulsed CO2 laser and high-intensity focused ultrasound. The patients in group L had no significant adverse reactions during the operation and needed no special postoperative treatment. The total effective rate in group L was 96.7%. In group U, five patients felt mild burning during the operation, painful blisters arose on the skin of the ablated area, and long-lasting local edema was observed. Seven patients had subcutaneous nodules. The total effective rate in group U was 90.0%. CONCLUSIONS: Fractional ultrapulsed CO2 laser is a minimally invasive, effective, and safe treatment for white lesions of the vulva. It causes few complications and does not affect the daily and working life of patients. Therefore, it should be widely applied in clinical practice.

Shifts in potential geographical distribution of Pterocarya stenoptera under climate change scenarios in China.

Climate change poses a serious threat to biodiversity. Predicting the effects of climate change on the distribution of a species' habitat can help humans address the potential threats which may change the scope and distribution of species. Pterocarya stenoptera is a common fast-growing tree species often used in the ecological restoration of riverbanks and alpine forests in central and eastern China. Until now, the characteristics of the distribution of this species' habitat are poorly known as are the environmental factors that influence its preferred habitat. In the present study, the Maximum Entropy Modeling (Maxent) algorithm and the Genetic Algorithm for Ruleset Production (GARP) were used to establish the models for the potential distribution of this species by selecting 236 sites with known occurrences and 14 environmental variables. The results indicate that both models have good predictive power. Minimum temperature of coldest month (Bio6), mean temperature of warmest quarter (Bio10), annual precipitation (Bio12), and precipitation of driest month (Bio14) were important environmental variables influencing the prediction of the Maxent model. According to the models, the temperate and subtropical regions of eastern China had high environmental suitability for this species, where the species had been recorded. Under each climate change scenario, climatic suitability of the existing range of this species increased, and its climatic niche expanded geographically to the north and higher elevation. GARP predicted a more conservative expansion. The projected spatial and temporal patterns of P. stenoptera can provide reference for the development of forest management and protection strategies.

Amphicarpic plants: definition, ecology, geographic distribution, systematics, life history, evolution and use in agriculture.

Although most plants produce all of their fruits (seeds) aboveground, amphicarpic species produce fruits (seeds) both above- and belowground. Our primary aims were to determine the number of reported amphicarpic species and their taxonomic, geographic, life form and phylogenetic distribution, to evaluate differences in the life history of plants derived from aerial and subterranean seeds, to discuss the ecological and evolutionary significance of amphicarpy, to explore the use of amphicarpic plants in agriculture, and to suggest future research directions for studies on amphicarpy. Amphicarpy occurs in at least 67 herbaceous species (31 in Fabaceae) in 39 genera and 13 families of angiosperms distributed in various geographical regions of the world and in various habitats. Seeds from aerial and subterranean fruits differ in size/mass, degree of dormancy, dispersal and ability to form a persistent seed bank, with aerial seeds generally being smaller, more dormant and more likely to be dispersed and to form a seed bank than subterranean seeds. In addition, plants produced by aerial and subterranean seeds may differ in survival and growth, competitive ability and biomass allocation to reproduction. Amphicarpic plants may exhibit a high degree of plasticity during reproduction. Subterranean fruits are usually formed earlier than aerial ones, and plants may produce only subterranean propagules under stressful environmental conditions. Differences in the life histories of plants from aerial and subterranean seeds may be an adaptive bet-hedging strategy.

Achene heteromorphism in Bidens pilosa (Asteraceae): differences in germination and possible adaptive significance.

Bidens pilosa (Asteraceae), a noxious weed in many ecosystems worldwide, produces large amounts of heteromorphic (central and peripheral) achenes. The primary aims of the present study were to compare the morphological, dormancy/germination characteristics of dimorphic achenes. Temperatures simulating those in the natural habitat of B. pilosa were used to test for primary dormancy and germination behaviour of fresh central and peripheral achenes. The effects of cold stratification, gibberellic acid (GA3) and dry storage on breaking dormancy were tested and the germination percentage of dimorphic achenes in response to osmotic stress was measured. Cold stratification, GA3 and dry storage significantly increased the germination percentage, suggesting both types of achenes had non-deep physiological dormancy. Variously pretreated central achenes had significantly higher germination percentages than peripheral achenes. Central achenes were more osmotically tolerant than peripheral achenes with a high germination percentage in high polyethylene glycol concentrations. These above differences among dimorphic achenes of B. pilosa increased the species' fitness to adapt to heterogeneous habitats creating an ecological adaptive strategy that may allow B. pilosa to successfully thrive in stressful habitats.

Maxent modeling for predicting the potential geographical distribution of two peony species under climate change.

Paeonia (Paeoniaceae), an economically important plant genus, includes many popular ornamentals and medicinal plant species used in traditional Chinese medicine. Little is known about the properties of the habitat distribution and the important eco-environmental factors shaping the suitability. Based on high-resolution environmental data for current and future climate scenarios, we modeled the present and future suitable habitat for P. delavayi and P. rockii by Maxent, evaluated the importance of environmental factors in shaping their distribution, and identified distribution shifts under climate change scenarios. The results showed that the moderate and high suitable areas for P. delavayi and P. rockii encompassed ca. 4.46×105km2 and 1.89×105km2, respectively. Temperature seasonality and isothermality were identified as the most critical factors shaping P. delavayi distribution, and UVB-4 and annual precipitation were identified as the most critical for shaping P. rockii distribution. Under the scenario with a low concentration of greenhouse gas emissions (RCP2.6), the range of both species increased as global warming intensified; however, under the scenario with higher concentrations of emissions (RCP8.5), the suitable habitat range of P. delavayi decreased while P. rockii increased. Overall, our prediction showed that a shift in distribution of suitable habitat to higher elevations would gradually become more significant. The information gained from this study should provide a useful reference for implementing long-term conservation and management strategies for these species.