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"Omics" typically involves exploration of the structure and function of the entire composition of a biological system at a specific level using high-throughput analytical methods to probe and analyze large amounts of data, including genomics, transcriptomics, proteomics, and metabolomics, among other types. Genomics characterizes and quantifies all genes of an organism collectively, studying their interrelationships and their impacts on the organism. However, conventional transcriptomic sequencing techniques target population cells, and their results only reflect the average expression levels of genes in population cells, as they are unable to reveal the gene expression heterogeneity and spatial heterogeneity among individual cells, thus masking the expression specificity between different cells. Single-cell transcriptomic sequencing and spatial transcriptomic sequencing techniques analyze the transcriptome of individual cells in plant or animal tissues, enabling the understanding of each cell's metabolites and expressed genes. Consequently, statistical analysis of the corresponding tissues can be performed, with the purpose of achieving cell classification, evolutionary growth, and physiological and pathological analyses. This article provides an overview of the research progress in plant single-cell and spatial transcriptomics, as well as their applications and challenges in plants. Furthermore, prospects for the development of single-cell and spatial transcriptomics are proposed.
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Background: It introduced an artefactual field experiment to analyze the influence of incentives from fee-for-service (FFS) and diagnosis-intervention package (DIP) payments on physicians' provision of medical services. Methods: This study recruited 32 physicians from a national pilot city in China and utilized an artefactual field experiment to examine medical services provided to patients with different health status. Results: In general, the average quantities of medical services provided by physicians under the FFS payment were higher than the optimal quantities, the difference was statistically significant. While the average quantities of medical services provided by physicians under the DIP payment were very close to the optimal quantities, the difference was not statistically significant. Physicians provided 24.49, 14.31 and 5.68% more medical services to patients with good, moderate and bad health status under the FFS payment than under the DIP payment. Patients with good, moderate and bad health status experienced corresponding losses of 5.70, 8.10 and 9.42% in benefits respectively under the DIP payment, the corresponding reductions in profits for physicians were 10.85, 20.85 and 35.51%. Conclusion: It found patients are overserved under the FFS payment, but patients in bad health status can receive more adequate treatment. Physicians' provision behavior can be regulated to a certain extent under the DIP payment and the DIP payment is suitable for the treatment of patients in relatively good health status. Doctors sometimes have violations under DIP payment, such as inadequate service and so on. Therefore, it is necessary to innovate the supervision of physicians' provision behavior under the DIP payment. It showed both medical insurance payment systems and patients with difference health status can influence physicians' provision behavior.
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Planes de Aranceles por Servicios , Humanos , China , Planes de Aranceles por Servicios/economía , Masculino , Femenino , Seguro de Salud/estadística & datos numéricos , Seguro de Salud/economía , Médicos/economía , Médicos/estadística & datos numéricos , Pautas de la Práctica en Medicina/economía , Pautas de la Práctica en Medicina/estadística & datos numéricos , Adulto , Persona de Mediana Edad , Estado de SaludRESUMEN
Dwarf bamboo (Indocalamus decorus) is an O3-tolerant plant species. To identify the possible mechanism and response of leaf morphological, antioxidant, and anatomical characteristics to elevated atmospheric O3 (EO3) concentrations, we exposed three-year-old I. decorus seedlings to three O3 levels (low O3-LO: ambient air; medium O3-MO: Ambient air+70 ppb high O3-HO: Ambient air+140 ppb O3) over a growing season using open-top chambers. Leaf shape and stomatal characteristics, and leaf microscopic structure of I. decorus were examined. The results indicated that 1) the stomata O3 flux (Fst) of HO decreased more rapidly under EO3 as the exposure time increased. The foliar O3 injury of HO and MO occurred when AOT40 was 26.62 ppm h and 33.20 ppm h, respectively, 2) under EO3, leaf number, leaf mass per area, leaf area, and stomata length/width all decreased, while leaf thickness, stomatal density, width, and area increased compared to the control, 3) MDA and total soluble protein contents all showed significantly increase under HO (36.57% and 32.77%) and MO(31.91% and 19.52%) while proline contents only increased under HO(33.27%). 4) MO and HO increased bulliform cells numbers in the leaves by 6.28% and 23.01%, respectively. HO reduced the transverse area of bulliform cells by 13.73%, while MO treatments had no effect, and 5) the number of fusoid cells interspace, the transverse area of fusoid cells interspace, and mesophyll thickness of HO significantly increased by 11.16%, 28.58%, and 13.42%, respectively. In conclusion, I. decorus exhibits strong O3 tolerance characteristics, which stem from adaptions in the leaf's morphological, structural, antioxidant, and anatomical features. One critical attribute was the enlargement of the bulliform cell transverse area and the transverse area of fusoid cells interspace that drove this resistance to O3. Local bamboo species with high resistance to O3 pollution thus need to be promoted for sustained productivity and ecosystem services in areas with high O3 pollution.
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Contaminantes Atmosféricos , Ozono , Hojas de la Planta , Hojas de la Planta/anatomía & histología , Hojas de la Planta/efectos de los fármacos , Ozono/toxicidad , Contaminantes Atmosféricos/toxicidad , Contaminantes Atmosféricos/análisis , Poaceae/efectos de los fármacos , Poaceae/anatomía & histología , Estomas de Plantas/efectos de los fármacos , Estomas de Plantas/anatomía & histologíaRESUMEN
There are limited studies on the cytology of bamboo leaf development from primordium to maturity. This study delves into the leaf morphological characteristics and growth patterns of Sasaella kogasensis 'Aureostriatus' and provides a three-dimensional anatomical analysis of cell division, expansion, and degradation. Leaves on the same branch develop bottom-up, while individual leaves develop the other way around. Like bamboo shoots and culms, the leaves follow a "slow-fast-slow" growth pattern, with longitudinal growth being predominant during their development. The growth zones of individual leaves included division, elongation, and maturation zones based on the distribution of growth space. By measuring 13,303 epidermal long cells and 3293 mesophyll cells in longitudinal sections of rapidly elongating leaves, we observed that in the rapid elongation phase (S4-S5), the division zone was located in the 1-2 cm segment at the bottom of the leaf blade and maintained a constant size, continuously providing new cells for leaf elongation, whereas in the late rapid elongation phase (S6), when the length of the leaf blade was approaching that of a mature leaf, its cells at the bottom of the blade no longer divided and were replaced by the ability to elongate. Furthermore, to gain an insight into the dynamic changes in the growth of the S. kogasensis 'Aureostriatus' leaves in the lateral and periclinal directions, the width and thickness of 1459 epidermal and 2719 mesophyll cells were counted in the mid-cross section of leaves at different developmental stages. The results showed that during the early stages of development (S1-S3), young leaves maintained vigorous division in the lateral direction, while periplasmic division gradually expanded from the bottom to the top of the leaf blade and the number of cell layers stabilized at S4. The meristematic tissues on both sides of the leaf were still able to divide at S4 but the frequency of the division gradually decreased, while cell division and expansion occurred simultaneously between the veins. At S6, the cells at the leaf margins and between the veins were completely differentiated and the width of the leaf blade no longer expanded. These findings revealed changes in cell growth anisotropically during the leaf development of S. kogasensis 'Aureostriatus' and demonstrated that leaf elongation was closely related to the longitudinal expansion of epidermal cells and proliferative growth of mesophyll cells, whereas the cell division of meristematic tissues and expansion of post-divisional cells contributed to the increases in blade width and thickness. The presented framework will facilitate a further exploration of the molecular regulatory mechanisms of leaf development in S. kogasensis 'Aureostriatus' and provide relevant information for developmental and taxonomic studies of bamboo plants.
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Phyllostachys nigra has green young culms (S1) and purple black mature culms (S4). Anthocyanins are the principal pigment responsible for color presentation in ornamental plants. We employ a multi-omics approach to investigate the regulatory mechanisms of anthocyanins in Ph. nigra. Firstly, we found that the pigments of the culm of Ph. nigra accumulated only in one to four layers of cells below the epidermis. The levels of total anthocyanins and total flavonoids gradually increased during the process of bamboo culm color formation. Metabolomics analysis indicated that the predominant pigment metabolites observed were petunidin 3-O-glucoside and malvidin O-hexoside, exhibiting a significant increase of up to 9.36-fold and 13.23-fold, respectively, during pigmentation of Ph. nigra culm. Transcriptomics sequencing has revealed that genes involved in flavonoid biosynthesis, phenylpropanoid biosynthesis, and starch and sucrose metabolism pathways were significantly enriched, leading to color formation. A total of 62 differentially expressed structural genes associated with anthocyanin synthesis were identified. Notably, PnANS2, PnUFGT2, PnCHI2, and PnCHS1 showed significant correlations with anthocyanin metabolites. Additionally, certain transcription factors such as PnMYB6 and PnMYB1 showed significant positive or negative correlations with anthocyanins. With the accumulation of sucrose, the expression of PnMYB6 is enhanced, which in turn triggers the expression of anthocyanin biosynthesis genes. Based on these findings, we propose that these key genes primarily regulate the anthocyanin synthesis pathway in the culm and contribute to the accumulation of anthocyanin, ultimately resulting in the purple-black coloration of Ph. nigra.
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Antocianinas , Transcriptoma , Antocianinas/metabolismo , Metaboloma , Flavonoides/genética , Sacarosa , Regulación de la Expresión Génica de las Plantas , Perfilación de la Expresión Génica/métodos , ColorRESUMEN
BACKGROUND: Traditional knowledge associated with medicinal food plants (MFPs) plays a vital role in fighting hidden hunger and safeguarding the health of local people. MFPs resources are abundant in the Gaoligongshan area, a biosphere reserve with the richest biocultural diversity in China. Local people of different linguistic groups also have rich traditional botanical knowledge. However, there are still few comprehensive and systematic studies on MFPs there. METHODS: Ethnobotanical investigation including market survey, semi-structured interviews, free listing and key informant interviews was conducted in the Gaoligongshan area, Western Yunnan, Southwest China. A total of 13 local farmers' markets were selected and information about medicinal food plants, including food categories, medicinal and edible parts, modes of consumption, medicinal effects, and distribution were collected. The relative occurrence frequency (RFO) and cultural food significance index (CFSI) were calculated to identify the culturally significant MFPs. RESULTS: A total of 184 species of MFPs, belonging to 83 families, were collected in the Gaoligongshan area, including vegetables (77), medicinal diets (26), fruits (25), spices (18), herbal tea (13), tea substitutes (11), substitutes for staple food (8), nuts (5), oils and fats (4), and dye material (1). The most frequently used families were Fabaceae, Asteraceae and Apiaceae, with 11, 10, and 9 species, respectively. The most frequently used plant parts were the stems, followed by fruits and leaves. Based on the evaluation results of the CFSI and RFO indices, 18 species of MFPs with magnificent local cultural importance have been screened out, such as Houttuynia cordata, Eryngium foetidum, Sechium edule, Centella asiatica and Pseudocydonia sinensis. CONCLUSION: These findings have guiding significance for conservation of traditional knowledge associated with MFPs and facilitation of scientific utilization of MFPs to meet local people's needs for a healthy life.
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Plantas Comestibles , Plantas Medicinales , Humanos , China , Etnobotánica/métodos , VerdurasRESUMEN
Leaf growth initiates in the peripheral region of the meristem at the apex of the stem, eventually forming flat structures. Leaves are pivotal organs in plants, serving as the primary sites for photosynthesis, respiration, and transpiration. Their development is intricately governed by complex regulatory networks. Leaf development encompasses five processes: the leaf primordium initiation, the leaf polarity establishment, leaf size expansion, shaping of leaf, and leaf senescence. The leaf primordia starts from the side of the growth cone at the apex of the stem. Under the precise regulation of a series of genes, the leaf primordia establishes adaxial-abaxial axes, proximal-distal axes and medio-lateral axes polarity, guides the primordia cells to divide and differentiate in a specific direction, and finally develops into leaves of a certain shape and size. Leaf senescence is a kind of programmed cell death that occurs in plants, and as it is the last stage of leaf development. Each of these processes is meticulously coordinated through the intricate interplay among transcriptional regulatory factors, microRNAs, and plant hormones. This review is dedicated to examining the regulatory influences of major regulatory factors and plant hormones on these five developmental aspects of leaves.
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BACKGROUND: Immense attention has been given to the outcome of COVID-19 infection. However, comprehensive studies based on large populational cohort with long-term follow-up are still lacking. This study aimed to investigate the risk of various short-term comorbidities (within one month) and long-term sequelae (above one month) after COVID-19 infection. METHODS: In this large prospective cohort study with 14 months follow-up information based on UK biobank, we included 16,776 COVID-19-positive participants and 58,281 COVID-19-negative participants matched for comparison. The risk of each comorbidity and sequela was evaluated by multivariable logistic regression analysis and presented as hazard ratio (HR) and 95% confidence interval (95% CI). RESULTS: COVID-19-positive individuals had a higher risk of 47 types of comorbidities within one month following COVID-19 infection, especially those who were older, male, overweight/obese, ever-smoked, with more pre-existing comorbidities and hospitalized. About 70.37% of COVID-19 patients with comorbidities had more than one co-occurring comorbidities. Additionally, only 6 high-risk sequelae were observed after one month of COVID-19 infection, and the incidence was relatively low (< 1%). CONCLUSION: In addition to long-term sequelae following COVID-19 infection, plenty of comorbidities were observed, especially in patients with older age, male gender, overweight/obese, more pre-existing comorbidities and severe COVID-19, indicating that more attention should be given to these susceptible persons within this period.
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COVID-19 , Humanos , Masculino , COVID-19/epidemiología , Estudios Prospectivos , Sobrepeso/epidemiología , SARS-CoV-2 , Comorbilidad , Progresión de la Enfermedad , Obesidad/epidemiologíaRESUMEN
Bamboo has great economic values and is used extensively in many industries, and their natural distribution range was divided into 12 zones in China according to the temperature of their geographical distribution in previous works. Different bamboo species had significantly different abilities in low-temperature tolerance, which need to be considered carefully during ex-situ introduction. In this paper, we observed and evaluated the low-temperature damage of 19 bamboo species in winter, and measured the physiological changes of bamboo leaves. A total of 3060 leaf samples were obtained from 102 core collections in 34 bamboo species from the 5 regions of Chinese mainland for anatomical comparison, in order to screen out the key anatomical indicators related to their low-temperature tolerance and to establish a mathematical prediction model for bamboo introduction. The results showed that the low-temperature resistance of clustered bamboos was generally lower than that of the scattered bamboos. The decreased temperature led to the constant decrease of net photosynthetic rate and transpiration rate, but the increase of soluble sugar content in all bamboo species. There was no dormancy for all bamboo species in winter. The temperate bamboos showed lower photosynthesis as compared to tropical bamboos in winter. The leaf shape of bamboos was closely related to their distribution. A total of 13 leaf indicators were screened and more suitable to estimate the low-temperature tolerant abilities of bamboos and to predict their distribution. The MNLR (multiple nonlinear regression) mathematical model showed the highest fitting degree and the optimal prediction ability in the potential northernmost introduction range of bamboos. This study lay a foundation for bamboo introduction, and could also reduce the economic losses caused by the wrong introduction.
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Moso bamboo is capable of both sexual and asexual reproduction during natural growth, resulting in four distinct types of culms: the bamboo shoot-culm, the seedling stem, the leptomorph rhizome, and a long-ignored culm-the outward-rhizome. Sometimes, when the outward rhizomes break through the soil, they continue to grow longitudinally and develop into a new individual. However, the roles of alternative transcription start sites (aTSS) or termination sites (aTTS) as well as alternative splicing (AS) have not been comprehensively studied for their development. To re-annotate the moso bamboo genome and identify genome-wide aTSS, aTTS, and AS in growing culms, we utilized single-molecule long-read sequencing technology. In total, 169,433 non-redundant isoforms and 14,840 new gene loci were identified. Among 1311 lncRNAs, most of which showed a positive correlation with their target mRNAs, one-third of these IncRNAs were preferentially expressed in winter bamboo shoots. In addition, the predominant AS type observed in moso bamboo was intron retention, while aTSS and aTTS events occurred more frequently than AS. Notably, most genes with AS events were also accompanied by aTSS and aTTS events. Outward rhizome growth in moso bamboo was associated with a significant increase in intron retention, possibly due to changes in the growth environment. As different types of moso bamboo culms grow and develop, a significant number of isoforms undergo changes in their conserved domains due to the regulation of aTSS, aTTS, and AS. As a result, these isoforms may play different roles than their original functions. These isoforms then performed different functions from their original roles, contributing to the transcriptomic complexity of moso bamboo. Overall, this study provided a comprehensive overview of the transcriptomic changes underlying different types of moso bamboo culm growth and development.
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Perfilación de la Expresión Génica , Transcriptoma , Empalme Alternativo , Isoformas de Proteínas/genética , Poaceae/genética , Crecimiento y Desarrollo , Regulación de la Expresión Génica de las PlantasRESUMEN
Woody bamboos have peculiar flowering characteristics with intervals ranging from several years to more than 100 years. Elucidating flowering time and reproductive development in bamboo could be beneficial for both humans and wildlife. To identity the mechanisms responsible for flowering time and embryo abortion in Bambusa oldhamii 'Xia Zao' ZSX, a transcriptome sequencing project was initiated to characterize the genes involved in developing flowers in this bamboo species. Morphological studies showed that pollen abortion in this bamboo species was mainly caused by a delay in tapetum degradation and abnormal meiotic process. Differential expression (DE) and optimized hierarchical clustering analyses identified three of nine gene expression clusters with decreasing expression at the meiosis of flowering stages. Together with enriched Gene Ontology Biological Process terms for meiosis, this suggests that their expression pattern may be associated with aborted meiosis in B. oldhamii 'Xia Zao'. Moreover, our large-scale phylogenomic analyses comparing meiosis-related transcripts of B. oldhamii 'Xia Zao' with well annotated genes in 22 representative angiosperms and sequence evolution analyses reveal two core meiotic genes NO EXINE FORMATION 1 (NFE1) and PMS1 with nonsense mutations in their coding regions, likely providing another line of evidence supporting embryo abortion in B. oldhamii 'Xia Zao'. Similar analyses, however, reveal conserved sequence evolution in flowering pathways such as LEAFY (LFY) and FLOWERING LOCUS T (FT). Seventeen orthogroups associated with flowering were identified by DE analyses between nonflowering and flowering culm buds. Six regulators found primarily in several connected network nodes of the photoperiod pathway were confirmed by mapping to the flowering time network in rice, such as Heading date (Hd3a) and Rice FT-like 1 (RFT1) which integrate upstream signaling into the downstream effectors. This suggests the existence of an intact photoperiod pathway is likely the key regulators that switch on/off flowering in B. oldhamii 'Xia Zao'.
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SQUAMOSA Promoter-Binding Protein-Like (SPL) family is well-known for playing an important role in plant growth and development, specifically in the reproductive process. Bamboo plants have special reproductive characteristics with a prolonged vegetative phase and uncertain flowering time. However, the underlying functions of SPL genes in reproductive growth are undisclosed in bamboo plants. In the study, a total of 28 SPLs were screened from an ornamental dwarf bamboo species, Pleioblastus pygmaeus. Phylogenetic analysis indicates that 183 SPLs from eight plant species can be classified into nine subfamilies, and the 28 PpSPLs are distributed among eight subfamilies. Homologous analysis shows that as many as 32 pairs of homologous genes were found between P. pygmaeus and rice, and 83 pairs were found between P. pygmaeus and Moso bamboo, whose Ka/Ks values are all <1. MiRNA target prediction reveals that 13 out of the 28 PpSPLs have recognition sites complementary to miRNA156. To screen the SPLs involved in the reproductive growth of bamboo plants, the mRNA abundance of the 28 PpSPLs was profiled in the different tissues of flowering P. pygmaeus and non-flowering plants by RNA-Seq. Moreover, the relative expression level of eight PpSPLs is significantly higher in flowering P. pygmaeus than that in non-flowering plants, which was also validated by RT-qPCR. Combined with phylogenetic analysis and homologous analysis, the eight significant, differentially expressed PpSPLs were identified to be associated with the reproductive process and flower organ development. Among them, there are four potential miRNA156-targeting PpSPLs involved in the flowering process. Of significant interest in the study is the identification of 28 SPLs and the exploration of four key flowering-related SPLs from P. pygmaeus, which provides a theoretic basis for revealing the underlying functions of SPLs in the reproductive growth of bamboo plants.
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Flores , Regulación de la Expresión Génica de las Plantas , Flores/metabolismo , Proteínas Portadoras/metabolismo , Filogenia , Poaceae/metabolismoRESUMEN
Skin wound healing is an intractable problem that represents an urgent clinical need. To solve this problem, a large number of studies have focused on the use of exosomes (EXOs) derived from adipose-derived stem cells (ADSCs). This review describes the mechanisms whereby ADSCs-EXOs regulate wound healing and their clinical application. In the wound, ADSCs-EXOs modulate immune responses and inflammation. They also promote angiogenesis, accelerate proliferation and re-epithelization of skin cells, and regulate collagen remodelling which inhibits scar hyperplasia. Compared with ADSCs therapeutics, ADSCs-EXOs have highly stability and are easily stored. Additionally, they are not rejected by the immune system and have a homing effect and their dosage can be easily controlled. ADSCs-EXOs can improve fat grafting and promote wound healing in patients with diabetes mellitus. They can also act as a carrier and combined scaffold for treatment, leading to scarless cutaneous repair. Overall, ADSCs-EXOs have the potential to be used in the clinic to promote wound healing.
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Adipocitos/citología , Exosomas/metabolismo , Piel/citología , Células Madre/citología , Cicatrización de Heridas/fisiología , Animales , Exosomas/trasplante , Humanos , Células Madre Mesenquimatosas/citologíaRESUMEN
We, at first, fully characterized the complete chloroplast genome of the woody bamboo Acidosasa gigantea using genome skimming and focused on comparative analyses among Acidosasa and Indosasa. This newly sequenced chloroplast genome (GenBank NO. MN917206) is a typical circular structure with 139,711 bp in length and comprises of an 83,295 bp large single-copy (LSC) region, a 12,824 bp small single-copy (SSC) region, and a pair of 21,796 bp inverted repeats (IRs). The GC content of A. gigantea is 38.9% and the sequences contained 132 unique genes were successfully annotated, including 39 tRNA genes, 8 rRNA genes, and 85 protein-coding genes. Phylogenetic analysis shows that A. gigantea is highly clustered in the Arundinaria clade (clade VI) of Arundinarieae, a sister of the clade of Acidosasa purpurea and was not clustered on the same branch as Indosasa sinica. Therefore, it is more accurate to classify A. gigantea into Acidosasa.
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BACKGROUND: NAC (NAM, ATAF1-2, and CUC2) family is one of the largest plant-specific transcription factor families known to play significant roles in plant development processes and stress responses. RESULTS: In the study, a total of 112 NACs were identified to be differentially expressed in the comparisons of leaves and stems, leaves and roots, roots and stems of Populus simonii×P. nigra among 289 members by RNA-Seq. And 148, 144 and 134 NACs were detected to be salt-responsive in the roots, stems and leaves under 150 mM NaCl stress, respectively. Among them, a total of 53 salt-responsive NACs were shared across the three tissues. Under salt stress, 41/37 NACs were identified to be up/down-regulated in the leaves of Populus simonii × P.nigra among 170 non-redundant NACs by RT-qPCR, which was similar with RNA-Seq results. The expression pattern analysis of 6 NACs including four randomly up-regulated genes (NAC86, NAC105, NAC139 and NAC163) and two down-regulated genes (NAC15 and NAC149) indicated a few NACs showed specific temporal and spatial expression patterns in the three tissues of Populus simonii×P.nigra. Based on transcriptome screening and phylogenic analysis of differentially expressed NACs in different tissues under salt stress, 18 potential NACs associated with wood formation and 20 involved in stress responses were identified in Populus simonii×P.nigra. CONCLUSIONS: The study further gains an understanding of the connection of tissue specificity and gene function in poplar, and lays the foundation of functional analysis of poplar NACs in stress responses.
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Proteínas de Plantas/genética , Populus/genética , Estrés Salino/genética , Transcriptoma , Perfilación de la Expresión Génica , Especificidad de Órganos , Filogenia , Hojas de la Planta/genética , Hojas de la Planta/fisiología , Raíces de Plantas/genética , Raíces de Plantas/fisiología , Tallos de la Planta/genética , Tallos de la Planta/fisiología , Populus/fisiología , Factores de Transcripción/genética , MaderaRESUMEN
Bamboo is a perennial flowering plant with a distinctive life cycle: many bamboo species remain in the vegetative phase for decades, followed by mass synchronous flowering and subsequent death. The phenomenon of bamboo flowering is not fully understood, but its periodicity is a major research focus. Here, we collected information on bamboo flowering events by investigating historical documents and field studies at the Bamboo Research Institute of Nanjing Forestry University. We compiled information on more than 630 flowering events, 124 of which accurately recorded the flowering cycle time. We summarized the specific flowering cycles of 85 bamboo species, as well as four kinds of bamboo flowering habits in detail. We present a theory of the bamboo flowering cycle and discuss the reasons for the observed variations in bamboo flowering. This review also introduces two mechanisms by which bamboo forests are rejuvenated after flowering and explains the flowering phenomena of bamboo forests using the bamboo flowering cycle theory. Finally, we present suggestions for forest management strategies. Bamboo flowering is a normal physiological phenomenon, even though it has unique elements compared with flowering in other plants. The results presented here provide valuable reference material for understanding bamboo flowering and its periodicity.
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Light extraction array, comprised of millions of discrete scattering dots randomly distributed on edge-lit light guide plates (LGPs), determines both the light efficiency and spatial uniformity of liquid crystal displays. However, it is hard to define by a specific mathematical expression. Here, we propose a novel analytic design for light extraction array based on geometrical optical principles. This design method consists of three successive procedures evolving from point- and line-source approximations to extended surface-source computation. Three procedures are demonstrated via both simulation and experiment, and the key factors influencing the performance of the light extraction array are also discussed. Our approach with high accuracy and reduced complexity will have broad prospect for illumination design.
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We propose and fabricate a multi-primary-color (MPC) quantum-dot down-converting film (QDDCF). A four-primary-color QDDCF composed of red (R), yellowish green (YG), bluish green (BG), and blue (B) subpixels was fabricated via totally five rounds of photolithographic processes. A verification platform was built up using a laser projector, and the measured results show that the QD film can expand display color gamut to 118.60% of Rec. 2020 and can cover the entire Pointer's gamut. The issues of blue light absorption and film thickness are analyzed in detail. The combination of MPC technology and QDDCF is a potential strategy to realize ultra wide color gamut for emerging display technologies.
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We present an improved two-in-one polarization-interlaced liquid-crystal-on-silicon (LCoS) stereoscopic projection prototype employing a novel prism-array configuration and a specially designed illumination freeform lens group. The parallel prism configuration is designed based on the balance analysis between stereoscopic channels. For further system simplification, the illumination lens group, which consists of three prepositive aspherical surfaces and a single postpositive freeform one, is synthetically obtained from the Monge-Ampère method and feedback optimization. Design results show that the proposed prototype can well solve the problem of stereo-channel separation and integration, and provide both better performance and lower volume. It is proven to have potentiality replacing existing stereoscopic projectors.
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The principle of similarity (Thompson, 1917) states that the weight of an organism follows the 3/2-power law of its surface area and is proportional to its volume on the condition that the density is constant. However, the allometric relationship between leaf weight and leaf area has been reported to greatly deviate from the 3/2-power law, with the irregularity of leaf density largely ignored for explaining this deviation. Here, we choose 11 bamboo species to explore the allometric relationships among leaf area (A), density (ρ), length (L), thickness (T), and weight (W). Because the edge of a bamboo leaf follows a simplified two-parameter Gielis equation, we could show that A â L2 and that A â T2. This then allowed us to derive the density-thickness allometry ρ â Tb and the weight-area allometry W â A(b+3)/2 ≈ A9/8, where b approximates -3/4. Leaf density is strikingly negatively associated with leaf thickness, and it is this inverse relationship that results in the weight-area allometry to deviate from the 3/2-power law. In conclusion, although plants are prone to invest less dry mass and thus produce thinner leaves when the leaf area is sufficient for photosynthesis, such leaf thinning needs to be accompanied with elevated density to ensure structural stability. The findings provide the insights on the evolutionary clue about the biomass investment and output of photosynthetic organs of plants. Because of the importance of leaves, plants could have enhanced the ratio of dry material per unit area of leaf in order to increase the efficiency of photosynthesis, relative the other parts of plants. Although the conclusion is drawn only based on 11 bamboo species, it should also be applicable to the other plants, especially considering previous works on the exponent of the weight-area relationship being less than 3/2 in plants.