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Understanding how species' ecological niches adapt to environmental changes through time is critical for predicting the effect of future global change on endangered species. Yet few studies have incorporated knowledge of past niche shifting into the assessment of species' future fate in a changing world. In this study, we integrated the ecological niche dynamics into the species distribution modeling of the Asian crested ibis (Nipponia nippon) in East Asia. Specifically, we compared historical and present ecological niches of crested ibis in four-dimensional environmental space based on species occurrence and environmental data. We then employed a multi-temporal ecological niche model to estimate the potential geographical distribution of crested ibis under future climate and land-use changes. Our results show that crested ibis retained similar though not identical ecological niches over time. Compared to the historical baseline range, the current suitable habitat for crested ibis has been reduced by 39.6%. The effects of human activity outweigh those of climate change regarding the distribution of crested ibis. We conclude that the ecological niche of crested ibis was tended to be conservative, and future potentially suitable habitat may encounter northeastward and northwestward shift, and possibly expand by 18.7% referred to the historical range. The findings of our study are of clear importance for the conservation and successful reintroduction of crested ibis in East Asia.

Zinc oxide nanoparticles (ZnO-NPs) has been demonstrated to positively regulate plant tolerance to multiple environmental stresses. However, till date little information has been gained regarding the role of ZnO-NPs in the salt stress regulation in plants. Hence, the objective of our study was to investigate the role of ZnO-NPs in the regulation of salt tolerance in tomato (Lycopersicon esculentum Mill.). In this regard, the tomato plants were subjected to salt stress by using NaCl (150 mM) at the time of transplantation [15 days after sowing (DAS)]. Foliar application of ZnO-NPs at different levels viz., 10, 50 and 100 mg/L in the presence/absence of NaCl (150 mM) was carried out at 25 DAS and sampling was done at 35 DAS. Results of our study revealed that foliar spray of ZnO-NPs significantly increased shoot length (SL) and root length (RL), biomass, leaf area, chlorophyll content and photosynthetic attributes of tomato plants in the presence/absence of salt stress. Besides, the application of ZnO-NPs mitigates the negative impacts of salt stress on tomato growth, and enhanced protein content and antioxidative enzyme activity such as peroxidase (POX), superoxide dismutase (SOD) and catalase (CAT) under salt stress. In conclusion, the ZnO-NPs plays an important role in the alleviation of NaCl toxicity in tomato plants. Hence, the ZnO-NPs can be used to boost the growth performance and mitigate the adverse effects caused by NaCl in tomato.

Styrax is a gorgeous species combined with high medicinal and ornamental values, however, information about its floral scents is limited. This study aimed to reveal the floral scent compounds and the dynamic changes in the flowering process of Styrax japonicus, S. grandiflora and S. calvescens. Static headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry was adopted in the present study. The results showed that 24, 22 and 22 volatile compounds were present at three flowering stages, among which linalool, ocimene, α-pinene and germacrene D dominated in different species. Terpenes were the main floral scent compounds in all species, whereas there was considerable relative content of ketones in S. japonicus. Among the major terpenes, α-pinene, ocimene and myrcene were the common volatiles in these species, while β-elemene and allo-ocimene were the specific volatiles in S. japonicus and S. calvescens, respectively. The highest content of terpenes occurred at initial flowering stage in three species. The differences in the type and content of principal compounds contributed to the fragrance diversity among these species. A solid foundation for understanding the complexity of volatile emission could be obtained from our findings, meanwhile, effective utilization of abundant terpenes in flowers of Styrax species should be applied.

Purpose To determine the epidemiology characteristics of intestinal colonization of carbapenem-resistant Enterobacteriaceae (CRE) among inpatients in a pediatric hospital in China. Methods A retrospective study was conducted from April to December 2019. Medical records were reviewed to extract the clinical information. Antimicrobial susceptibility was performed by broth microdilution method. Drug resistance determinants and plasmid types were analyzed using polymerase chain reaction (PCR) assays. Multilocus sequence typing (MLST) and Enterobacterial repetitive intergenic consensus sequences PCR (ERIC-PCR) were employed to determine the genetic relationships between strains. Results A total of 90 CRE strains were isolated, with a fecal carriage rate of 8.6% (90/1052), and mainly distributed in E. aerogenes (n=30), K. pneumoniae (n=25) and E. coli (n=23). More than 50% of CRE colonizers had a history of invasive procedures and antibiotic exposures. As high as 91.1% (82/90) of CRE isolates carried carbapenemase genes, with bla NDM-5 (n=56) being the most common, and mainly found in E. aerogenes (51.8%, 29/56) and E. coli (32.1%, 18/56) isolates, which primarily belonged to ST4 (100%, 29/29) and ST692 (55.6%, 10/18), respectively. Followed by bla KPC-2 (n=12), and all found in K. pneumoniae ST11 isolates. Other carbapenemase genes including bla NDM-1, bla IMP-4 and bla IMP-26. Meanwhile, ESBL genes (bla CTX-M, bla TEM-1 and bla SHV) and AmpC genes (bla DHA-1 and bla EBC) were also detected. All CRE isolates showed high resistance to cephalosporins and carbapenemases (97.8%-100.0%) but remained susceptible to tigecycline (98.9%). IncX3 was a major plasmid type in NDM-containing strains (91.3%), and 91.7% of KPC-2-producing K. pneumoniae harboring IncFII and IncFIB plasmids. The ERIC-PCR revealed that several strains with identical STs were genetically similar. Conclusion This study revealed a major intestinal colonization of ST4 NDM-5 E. aerogenes, ST11 KPC-2 K. pneumoniae and ST692 NDM-5 E. coli strains among inpatients in a pediatric hospital. Infection control measures should be implemented immediately to prevent the spread of these strains in clinical settings.

Carbon competition between starch and oil biosynthesis during seed development of Styrax tonkinensis has been reported, but reserve dynamics indicate an absence of significant carbon competition in other Styrax species. The accumulation of different storage reserves during seed development can be competitive. Carbon competition (i.e., carbon flow into starch instead of oil) has been reported in Styrax tonkinensis (Pierre) Craib ex Hartwich. In this study, developmental patterns in morphology and the accumulation of major biochemical fractions of five other Styrax species (S. calvescens Perkins, S. dasyantha Perk., S. faberi Perk., S. japonicus Sieb. et Zucc., and S. odoratissimus Champ. ex Benth.) were analyzed over 50 days. In all species, kernel fresh matter and dry matter increased during development, while the percent water content trended downwards to lower than 40% at the last sampling date. The time to maturity varied with species, as did the evolution of oil, fatty acids composition, sugar, starch, and protein. Contents of these major reserve fractions per kernel increased with development and were strongly correlated with each other. Final oil concentration ranged from 489 to 548 mg g−1, and the proportions of major fatty acids (palmitic, oleic and linoleic acid) were similar across species (11–15%, 39–41% and 43–47%, respectively). In contrast, starch concentrations never exceeded 7–45 mg g−1, depending on species and developmental stage. Final protein concentration ranged from 165 to 237 mg g−1. A slowdown in the speed of oil accumulation midway during development may occur in S. faberi but was not present in the other species. None of the five Styrax species examined here presented evidence for significant carbon competition between starch and oil accumulation.

The objective of this research was to determine the effect of zinc oxide nanoparticles (ZnONPs) and/or salicylic acid (SA) under arsenic (As) stress on rice (Oryza sativa). ZnONPs are analyzed for various techniques viz., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). All of these tests established that ZnONPs are pure with no internal defects, and can be potentially used in plant applications. Hence, we further investigated for better understanding of the underlying mechanisms and the extent of ZnONPs and SA induced oxidative stress damages. More restricted plant growth, gas exchange indices, significant reduction in the SPAD index and maximum quantum yield (Fv/Fm) and brutal decline in protein content were noticed in As-applied plants. In contrast, foliar fertigation of ZnONPs and/or SA to As-stressed rice plants lessens the oxidative stress, as exposed by subordinate levels of reactive oxygen species (ROS) synthesis. Improved enzymatic activities of catalase (CAT), peroxidase (POX), and superoxide dismutase (SOD), proline and total soluble protein contents under ZnONPs and SA treatment plays an excellent role in the regulation of various transcriptional pathways participated in oxidative stress tolerance. Higher content of nitrogen (N, 13%), phosphorus (P, 10%), potassium (K, 13%), zinc (Zn, 68%), manganese (Mn, 14%), and iron (Fe, 19) in ZnONPs and SA treated plants under As-stress, thus hampered growth and photosynthetic efficiency of rice plants. Our findings suggest that toxicity of As was conquering by the application of ZnONPs and SA in rice plants.

Styrax japonicus is a small ornamental tree with medicinal values, although its flowering period is short. To date, information about the morphological and physiological characteristics of the petals during the flowering period is limited. In this study, we observed the structure of the petals at the full flowering stage with a scanning electron microscope and detected the contents of nutrients, minerals, and endogenous hormones and the activities of enzymes at different flowering stages. The results showed that the content of soluble sugar exhibited an ‘increase-decrease’ trend, whereas the contents of soluble protein, nitrogen (N), phosphorus (P), and abscisic acid (ABA) showed a ‘decrease-increase’ pattern. The content of starch descended continuously, but the contents of potassium (K), gibberellic acid (GA3), indoleacetic acid (IAA), and malondialdehyde (MDA) ascended continuously. The activities of peroxidase (POD) and superoxide dismutase (SOD) first rose and then declined during the flowering period. Higher contents of soluble sugar, N, K, and IAA promoted S. japonicus flowering, meanwhile, lower contents of starch, soluble protein, P, and GA3 in addition to the lower activity of SOD might be some of the causes of the short flowering period. This work will serve as the foundation for a scientific technique to utilize the flowers and extend the flowering period in S. japonicus.

Background: The faulty development of the root system is a major threat that affects the survival rate of container seedlings of Sapium sebiferum in the transplanting and reforestation processes. The current study was conducted to determine the impact of biochar on the root growth and development of S. sebiferum container seedlings. Methods: Varied concentrations (1%, 3%, and 5%) of straw and bamboo biochar were applied in six groups, whereas the control group (CK) was only treated with matrix. Results: The treatment with 3% straw biochar (C2) proved to be the most effective soil conditioner for cultivating S. sebiferum seedlings. Moreover, C2 increased seedling height (58.92%); ground diameter (33.86%, biomass of the over-ground part (12.73 g), the underground part (7.48 g), and the fibrous part (0.076 g) compared to the CK (control). Conclusions: Biochar not only improved the root morphology by developing primary lateral roots, but it also accelerated the assimilation of N from the matrix to indirectly facilitate stem growth through enhancing NR activity. The change in root growth strategy contributed to the growth in S. sebiferum seedlings, thereby improving the survival rate during transplanting and reforestation.

Background Styrax tonkinensis (Pierre) Craib ex Hartwich has great potential as a woody biodiesel species having seed kernels with high oil content, excellent fatty acid composition and good fuel properties. However, no transcriptome information is available on the molecular regulatory mechanism of oil accumulation in developing S. tonkinensis kernels. Results The dynamic patterns of oil content and fatty acid composition at 11 time points from 50 to 150 days after flowering (DAF) were analyzed. The percent oil content showed an up-down-up pattern, with yield and degree of unsaturation peaking on or after 140 DAF. Four time points (50, 70, 100, and 130 DAF) were selected for Illumina transcriptome sequencing. Approximately 73 million high quality clean reads were generated, and then assembled into 168,207 unigenes with a mean length of 854 bp. There were 5916 genes that were differentially expressed between different time points. These differentially expressed genes were grouped into 9 clusters based on their expression patterns. Expression patterns of a subset of 12 unigenes were confirmed by qRT-PCR. Based on their functional annotation through the Basic Local Alignment Search Tool and publicly available protein databases, specific unigenes encoding key enzymes, transmembrane transporters, and transcription factors associated with oil accumulation were determined. Three main patterns of expression were evident. Most unigenes peaked at 70 DAF, coincident with a rapid increase in oil content during kernel development. Unigenes with high expression at 50 DAF were associated with plastid formation and earlier stages of oil synthesis, including pyruvate and acetyl-CoA formation. Unigenes associated with triacylglycerol biosynthesis and oil body development peaked at 100 or 130 DAF. Conclusions Transcriptome changes during oil accumulation show a distinct temporal trend with few abrupt transitions. Expression profiles suggest that acetyl-CoA formation for oil biosynthesis is both directly from pyruvate and indirectly via acetaldehyde, and indicate that the main carbon source for fatty acid biosynthesis is triosephosphate originating from phosphohexose outside the plastid. Different sn-glycerol-3-phosphate acyltransferases are implicated in diacylglycerol biosynthesis at early versus late stages of oil accumulation. Triacylglycerol biosynthesis may be accomplished by both diacylglycerol and by phospholipid:diacylglycerol acyltransferases.

Background MicroRNAs (miRs) play an important role in osteoclastogenesis. However, no study has investigated the underlying molecular mechanisms of miR-145 in this process. The purpose of the present study was to investigate the role of miR-145 and its post-transcriptional mechanism in the progression of osteoclast differentiation. Methods Macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-kB ligand (RANKL) were used to induce osteoclastogenesis originated from bone marrow-derived macrophages (BMMs). Female C57BL/6J mice were divided into sham, OVX, OVX + NC-agomir and OVX + miR-145-agomir groups. Tartrate-resistant acid phosphatase (TRAP) staining was performed to identify osteoclasts in-vitro and in-vivo. The mRNA and protein levels in osteoclast and tibia were assayed by qRT-PCR and western blotting, respectively. Results miR-145 expression was inhibited in RANKL-induced osteoclastogenesis, whereas overexpression of miR-145 attenuated it. We further found that Smad3 is a direct target gene of miR-145 by binding with its 3′-UTR. Overexpression of miR-145 significantly suppressed Smad3 mRNA and protein expression. In-vivo, miR-145 agomir treatment inhibited osteoclast activity in OVX mice by inhibiting Smad3 expression. Conclusion We provide the evidence that over-expression of miR-145 could inhibit osteoclast differentiation, at least partially, by decreasing Smad3 expression.

Cadmium (Cd) is a trace element causing severe toxicity symptoms in plants, besides posing hazardous fitness issue due to its buildup in the human body through food chain. Nanoparticles (NPs) are recently employed as a novel strategy to directly ameliorate the Cd stress and acted as nano-fertilizers. The intend of the current study was to explore the effects of zinc oxide nanoparticles (ZnO-NPs; 50 mg/L) on plant growth, photosynthetic activity, elemental status and antioxidant activity in Oryza sativa (rice) under Cd (0.8 mM) stress. To this end, the rice plants are treated by Cd stress at 15 days after sowing (DAS), and the treatment was given directly into the soil. Supply of ZnO-NPs as foliar spray was given for five consecutive days from 30 to 35 DAS, and sampling was done at 45 DAS. However, rice plants supplemented with ZnO-NPs under the Cd toxicity revealed significantly increased shoot length (SL; 34.0%), root fresh weight (RFW; 30.0%), shoot dry weight (SDW; 23.07%), and root dry weight (RDW; 12.24%). Moreover, the ZnO-NPs supplement has also positive effects on photosynthesis related parameters, SPAD value (40%), chloroplast structure, and qualitatively high fluorescence observed by confocal microscopy even under Cd stress. ZnO-NPs also substantially prevented the increases of hydrogen peroxide (H2O2) and malondialdehyde (MDA) triggered by Cd. Physiological and biochemical analysis showed that ZnO-NPs increased enzymatic activities of superoxide dismutase (SOD; 59%), catalase (CAT; 52%), and proline (17%) that metabolize reactive oxygen species (ROS); these increases coincided with the changes observed in the H2O2 and MDA accumulation after ZnO-NPs application. In conclusion, ZnO-NPs application to foliage has great efficiency to improve biomass, photosynthesis, protein, antioxidant enzymes activity, mineral nutrient contents and reducing Cd levels in rice. This can be attributed mainly from reduced oxidative damage resulted due to the ZnO-NPs application.

Cadmium (Cd) stress is increasing at a high pace and is polluting the agricultural land. As a result, it affects animals and the human population via entering into the food chain. The aim of this work is to evaluate the possibility of amelioration of Cd stress through chitosan nanoparticles (CTS-NPs). After 15 days of sowing (DAS), Solanum lycopersicum seedlings were transplanted into maintained pots (20 in number). Cadmium (0.8 mM) was providing in the soil as CdCl2.2.5H2O at the time of transplanting, however, CTS-NPs (100 µg/mL) were given through foliar spray at 25 DAS. Data procured from the present experiment suggests that Cd toxicity considerably reduces the plant morphology, chlorophyll fluorescence, in addition to photosynthetic efficiency, antioxidant enzyme activity and protein content. However, foliar application of CTS-NPs was effective in increasing the shoot dry weight (38%), net photosynthetic rate (45%) and SPAD index (40%), while a decrease in malondialdehyde (24%) and hydrogen peroxide (20%) was observed at the 30 DAS stage as compared to control plants. On behalf of the current results, it is demonstrated that foliar treatment of CTS-NPs might be an efficient approach to ameliorate the toxic effects of Cd.

Nanoparticles (NPs) have recently emerged as potential agents for plants to ameliorate abiotic stresses by acting as nano-fertilizers. In this regard, the influence of the zinc oxide nanoparticles (ZnO-NPs) on plant responses to copper (Cu) stress has been poorly understood. Hence, the present study was executed to explore the role of ZnO-NPs (foliar) and 24-epibrassinolide (EBL; root dipping) individually or in combined form in the resilience of tomato (Solanum lycopersicum) plant to Cu stress. Tomato seeds were sown to make the nursery; and at 20 days after sowing (DAS) the plantlets were submerged in 10−8 M of EBL solution for 2 h, and subsequently transplanted in the soil-filled earthen pots. Cu concentration (100 mg kg−1) was applied to the soil at 30 DAS, whereas at 35 DAS plants were sprinkled with double distilled water (DDW; control), 50 mg/L of Zinc (Zn) and 50 mg/L of ZnO-NPs; and plant performance were evaluated at 45 DAS. It was evident that Cu-stress reduced photosynthesis (17.3%), stomatal conductance (18.1%), plant height (19.7%), and nitrate reductase (NR) activity (19.2%), but increased malondialdehyde (MDA; 29.4%), superoxide radical (O2-; 22.3%) and hydrogen peroxide (H2O2; 26.2%) content in S. lycopersicum. Moreover, ZnO-NPs and/or EBL implemented via different modes improved photosynthetic activity, stomatal aperture, growth, cell viability and activity of antioxidant enzymes and proline that augmented resilience of tomato plants to Cu stress. These observations depicted that application of ZnO-NPs and EBL could be a useful approach to assist Cu confiscation and stress tolerance against Cu in tomato plants grown in Cu contaminated sites.

This work provides a guideline for application of Taxodium ‘Zhongshanshan’ reference gene usage in the qRT-PCR system, and also for reference gene selection for other Taxodiaceae species. Quantitative real-time PCR (qRT-PCR) is a practical method which is frequently used for analysis of gene expression. However, many factors can affect the qRT-PCR analysis by influencing the quantitative measurement of the expression of genes. To avoid erroneous experimental analyses, it is necessary to select suitable reference genes for normalization of the variation. Taxodium ‘Zhongshanshan’ (T. ‘Zhongshanshan’) is an economically and ecologically important tree species in China for its extreme tolerance to several stresses. Although some responses of T. ‘Zhongshanshan’ to abiotic stresses have been studied, reference genes suitable for the normalization of qRT-PCR data under stresses have not previously been identified. Ten candidate reference genes were used to validate expression stability in this study, including actin (ACT), adenine phosphoribosyl transferase (APRT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), protein phosphatase 2A (PP2A), tubulin (TUB), 18S ribosomal RNA (18S rRNA), 25S ribosomal RNA (25S rRNA), ubiquitin extension protein (UBI), ubiquitin (UBQ), and SKP1/ASK-interacting protein (SKIP). To select appropriate reference genes, we selected a diverse set of samples representing different stress conditions. GeNorm and NormFinder were made to evaluate the result systematically. The results indicated that no single reference gene had an optimal performance across all the experimental systems, while, PP2A and APRT can be proposed as good starting points for gene-expression studies. The qRT-PCR analysis of pyruvate decarboxylase (PDC) expression patterns in response to half-waterlogging stress confirmed the reliability of selected stable reference genes. Our results have provided a guideline for application of T. ‘Zhongshanshan’ reference gene usage in the qRT-PCR system.

The carbon flow balance is shifted to starch rather than oil accumulation during benzoin seed development stage (80–120 DAF) and thereby lipid deposition speed slows down. Benzoin [Styrax tonkinensis (Pierre) Craib ex Hartwich] is a woody oilseed species with potential value as a biofuel feedstock. However, the continuous drop in seed crude fat concentration during maturation had remained unexplained until it was investigated in this study. Seed filling began 60 days after flowering (DAF), when the hexose-to-sucrose ratio dropped, correlating with substantial morphological changes in kernels. Oil accumulated 20 days earlier than starch, as the concentrations of free fatty acid (50–70 DAF) and diacylglycerols (50–80 DAF) increased rapidly. Fatty acid synthesis slowed between 80 and 120 days, correlating with a sharp increase in the speed of starch deposition, while triacylglycerol accumulation and the profile of fatty acids remained stable. Phosphoglucose isomerase (PGI), pyruvate dehydrogenase complex (PDHC), and malate dehydrogenase (MDH) activities dropped progressively together with acetyl coenzyme carboxylase (ACCase) after 70 DAF before the reserve storage priority shifted from fatty acids to starch. PGI, PDHC, MDH, ACCase, and diglyceride acyltransferase (DAGT) activities rose again at 120 DAF, after which the speed of fatty acid accumulation increased, correlating with a 10-day lag phase in starch accumulation. High glucose 6-phosphate dehydrogenase (G6PDH) activity was observed during oil deposition. Soluble protein continued accumulating as protease activity decreased during benzoin seed development, while the total amylase activity rose twice between 30 and 70 DAF before the ADP-glucose pyrophosphorylase activity and starch content soared high simultaneously after 70 DAF. The collective results suggest that carbon partitioning between starch and lipid accumulation occurs during benzoin kernel development and is responsible for a reduction in the rate at which total fatty acids accumulate between 80 and 120 DAF.

Adventitious root (AR) formation from cuttings is the primary manner for the commercial vegetative propagation of trees. Cuttings is also the main method for the vegetative reproduction of Taxodium &lsquo, Zhongshanshan&rsquo, while knowledge of the molecular mechanisms regulating the processes is limited. Here, we used mRNA sequencing and an isobaric tag for relative and absolute quantitation-based quantitative proteomic (iTRAQ) analysis to measure changes in gene and protein expression levels during AR formation in Taxodium &lsquo, Three comparison groups were established to represent the three developmental stages in the AR formation process. At the transcript level, 4743 genes showed an expression difference in the comparison groups as detected by RNA sequencing. At the protein level, 4005 proteins differed in their relative abundance levels, as indicated by the quantitative proteomic analysis. A comparison of the transcriptome and proteome data revealed regulatory aspects of metabolism during AR formation and development. In summary, hormonal signal transduction is different at different developmental stages during AR formation. Other factors related to carbohydrate and energy metabolism and protein degradation and some transcription factor activity levels, were also correlated with AR formation. Studying the identified genes and proteins will provide further insights into the molecular mechanisms controlling AR formation.

Microalgae have displayed great potential in wastewater treatment with simultaneous biomass production and nutrient removal. However, the characteristics of growth, nutrient removal varied greatly among microalgal species and also affected by light regimes. In this study, two microalgae Spirulina platensis (S.p.) and Scenedesmus obliquus (S.o.), belonging to cyanobacteria and green algae, were cultivated under the optimized light regimes respectively to investigate the biomass yield, biochemical components, nutrients removal and recovery from domestic wastewater. The results showed that based on the response surface methodology (RSM), the microalga S.o. preferred higher light intensity and daily illumination time than the S.p. and the models could predict the two microalgal biomass yields well respectively. Under the optimized light regimes, the microalga S.o. showed better growth in domestic wastewater with higher chlorophyll and lipid content than the S.p., while the microalga S.p. was rich in proteins and carbohydrates. The two microalgae both showed efficient nutrients removal from the domestic wastewater, but the microalga S.o. had higher nutrients recovery efficiencies than the S.p. despite for relatively lower TN removal. This study could provide sufficient information for applying the two microalgae in domestic wastewater treatment with simultaneous biomass production and nutrients recovery.

Bryophytes are sensitive to changing atmospheric conditions. Potentially, typical alpine bryophytes are valuable indicators of climate change for alpine ecosystems. However, little is known about the effects of climate change on the dominant alpine bryophytes of the Tibetan Plateau. In this study, we compared suitable habitats and predicted the effects of key environmental variables, in three climate change scenarios (RCP 2.6, RCP 4.5 and RCP 8.5), on the distribution of two dominant moss genera, a typically alpine xerophytic functional group, Bryoerythrophyllum and Didymodon in Pottiaceae. We used Maximum Entropy model (MaxEnt) modelling, for the 2050s and 2070s in Tibet. Simulation-based estimates suggest that Bryoerythrophyllum are more suited to habitats from semi-humid regions to semi-arid regions while Didymodon are relatively drought-resistant mosses that mainly inhabit drought regions. The variables associated with temperature will have the strongest effect on the future distribution patterns of both Bryoerythrophyllum and Didymodon when compared with precipitation and topographic variables. However, Climate change should affect Didymodon the most, due to its relatively narrow temperature and precipitation range for optimum growth. Additionally, Bryoerythrophyllum is predicted with a ratio of increase in suitable areas at 19.08%, 141.49% and 121.56% and 55.22%, 129.93% and 172.08% under all three scenarios, for 2050 and 2070, respectively. In contrast, Didymodon has a ratio of increase in suitable areas at −25.36%, 12.51% and 51.1% and 13.71%, 14.27% and 131.91%, for all three scenarios for the two future decades, respectively. However, there are more obviously regular expansions and contractions can be easily caught for Didymodon than for Bryoerythrophyllum with GHG emissions from low to high. In summary, although Bryoerythrophyllum and Didymodon are evolutionarily closely related and have similar distribution patterns and future upward and northward shifts, Didymodon will respond more to climate warming under each climatic scenario for the 2050s and 2070s. Therefore, Didymodon is recommended as an indicator of climate change on the Tibetan Plateau.

This study investigated the effects of water stress on the morphology and physiological responses in Pterocarya stenoptera seedlings originating from five provenances. Plants were subjected to water stress treatments for a period of up to 30 days. Under waterlogging stress, root morphology changed and increased numbers of adventitious roots were produced, resulting in enhanced growth. However, under drought stress, seedlings wilted more severely which resulted in plant death after day 9–15 of stress. Observations of external morphological changes revealed that seedlings from the HF (Hefeng) exhibited the least resistance to water stress. All of the other physiological indices, such as root vigor, MDA, soluble nutrition, proline, SOD, and POD, among others, were also affected. The rank of waterlogging-tolerance of plants originating from different provenances, which was evaluated synthetically by employing mathematical models, was: HS(Huoshan) > JN(Jiangning) > JJ(Jiujiang) > XN(Xiuning) > HF. With respect to drought-tolerance, the rank was: JJ > HS > XN > JN > HF.

Among the GRAS family of transcription factors, SHORT ROOT (SHR) and SCARECROW (SCR) are key regulators of the formation of root tissues. In this study, we isolated and characterized two genes encoding SHR proteins and one gene encoding an SCR protein: ThSHR1 (Accession Number MF045148), ThSHR2 (Accession Number MF045149) and ThSCR (Accession Number MF045152) in the adventitious roots of Taxodium hybrid ‘Zhongshanshan’. Gene structure analysis indicated that ThSHR1, ThSHR2 and ThSCR are all intron free. Multiple protein sequence alignments showed that each of the corresponding proteins, ThSHR1, ThSHR2 and ThSCR, contained five well-conserved domains: leucine heptad repeat I (LHRI), the VHIID motif, leucine heptad repeat II (LHR II), the PFYRE motif, and the SAW motif. The phylogenetic analysis indicated that ThSCR was positioned in the SCR clade with the SCR proteins from eight other species, while ThSHR1 and ThSHR2 were positioned in the SHR clade with the SHR proteins from six other species. Temporal expression patterns of these genes were profiled during the process of adventitious root development on stem cuttings. Whereas expression of both ThSHR2 and ThSCR increased up to primary root formation before declining, that of ThSHR1 increased steadily throughout adventitious root formation. Subcellular localization studies in transgenic poplar protoplasts revealed that ThSHR1, ThSHR2 and ThSCR were localized in the nucleus. Collectively, these results suggest that the three genes encode Taxodium GRAS family transcription factors, and the findings contribute to improving our understanding of the expression and function of SHR and SCR during adventitious root production, which may then be manipulated to achieve high rates of asexual propagation of valuable tree species.

Morphological and biochemical changes of Chinese horse chestnut (Aesculus chinensis Bge.) seeds were studied during the process of maturation. Fruit and seed diameter increased linearly from DPA (Days Post Anthesis) 60 to DPA 150 and were stable thereafter. The weight of fruit and seed increased sigmoidally between DPA 100 and DPA 160. The water contents of whole seeds, axes and cotyledons had a sharp reduction from DPA 110 to DPA 130 but changed little after DPA 130. The water contents of whole seeds, axes and cotyledons were 1.42, 1.93 and 1.30 g g−1DW, respectively at the end of maturation. The starch content of cotyledons from mature seeds was high on a dry weight basis (31.4%) while the total soluble sugar content varied between 12 and 20%. In both axes and cotyledons, the total soluble sugar content decreased during the process of maturation, as did all five soluble sugar components measured (glucose, sucrose, trehalose, raffinose and stachyose). Sucrose and stachyose contents remained relatively high at the time of seed maturation, followed by glucose and a trace level of trehalose. The oligosaccharide/disaccharide (O/D) ratio in the axes was 3.1 at DPA 140. The high level of sucrose and stachyose might contribute to the greater desiccation tolerance of Aesculus chinensis seeds relative to typical recalcitrant tropical seeds. High levels of ABA content in seed coats and a low GA3/ABA ratio in both seed coats and axes might also influence the desiccation tolerance and shallow dormancy of mature Aesculus chinensis seeds.