Coexpression of CD71 and CD117 Identifies an Early Unipotent Neutrophil Progenitor Population in Human Bone Marrow.

Neutrophils are the most abundant peripheral immune cells and thus, are continually replenished by bone marrow-derived progenitors. Still, how newly identified neutrophil subsets fit into the bone marrow neutrophil lineage remains unclear. Here, we use mass cytometry to show that two recently defined human neutrophil progenitor populations contain a homogeneous progenitor subset we term "early neutrophil progenitors" (eNePs) (Lin-CD66b+CD117+CD71+). Surface marker- and RNA-expression analyses, together with in vitro colony formation and in vivo adoptive humanized mouse transfers, indicate that eNePs are the earliest human neutrophil progenitors. Furthermore, we identified CD71 as a marker associated with the earliest neutrophil developmental stages. Expression of CD71 marks proliferating neutrophils, which were expanded in the blood of melanoma patients and detectable in blood and tumors from lung cancer patients. In summary, we establish CD117+CD71+ eNeP as the inceptive human neutrophil progenitor and propose a refined model of the neutrophil developmental lineage in bone marrow.

Routes to high-performance layered oxide cathodes for sodium-ion batteries.

Sodium-ion batteries (SIBs) are experiencing a large-scale renaissance to supplement or replace expensive lithium-ion batteries (LIBs) and low energy density lead-acid batteries in electrical energy storage systems and other applications. In this case, layered oxide materials have become one of the most popular cathode candidates for SIBs because of their low cost and comparatively facile synthesis method. However, the intrinsic shortcomings of layered oxide cathodes, which severely limit their commercialization process, urgently need to be addressed. In this review, inherent challenges associated with layered oxide cathodes for SIBs, such as their irreversible multiphase transition, poor air stability, and low energy density, are systematically summarized and discussed, together with strategies to overcome these dilemmas through bulk phase modulation, surface/interface modification, functional structure manipulation, and cationic and anionic redox optimization. Emphasis is placed on investigating variations in the chemical composition and structural configuration of layered oxide cathodes and how they affect the electrochemical behavior of the cathodes to illustrate how these issues can be addressed. The summary of failure mechanisms and corresponding modification strategies of layered oxide cathodes presented herein provides a valuable reference for scientific and practical issues related to the development of SIBs.

Stable inhibition of choroidal neovascularization by adeno-associated virus 2/8-vectored bispecific molecules.

Neovascular age-related macular degeneration (nAMD) causes severe visual impairment. Pigment epithelium-derived factor (PEDF), soluble CD59 (sCD59), and soluble fms-like tyrosine kinase-1 (sFLT-1) are potential therapeutic agents for nAMD, which target angiogenesis and the complement system. Using the AAV2/8 vector, two bi-target gene therapy agents, AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59, were generated, and their therapeutic efficacy was investigated in laser-induced choroidal neovascularization (CNV) and Vldlr-/- mouse models. After a single injection, AAV2/8-mediated gene expression was maintained at high levels in the retina for two months. Both AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59 significantly reduced CNV development for an extended period without side effects and provided efficacy similar to two injections of current anti-vascular endothelial growth factor monotherapy. Mechanistically, these agents suppressed the extracellular signal-regulated kinase and nuclear factor-κB pathways, resulting in anti-angiogenic activity. This study demonstrated the safety and long-lasting effects of AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59 in CNV treatment, providing a promising therapeutic strategy for nAMD.

Integrated analysis of transcriptome and miRNAome reveals the heat stress response of Pinellia ternata seedlings.

Pinellia ternata (Thunb.) Briet., a valuable herb native to China, is susceptible to the "sprout tumble" phenomenon because of high temperatures, resulting in a significant yield reduction. However, the molecular regulatory mechanisms underlying the response of P. ternata to heat stress are not well understood. In this study, we integrated transcriptome and miRNAome sequencing to identify heat-response genes, microRNAs (miRNAs), and key miRNA-target pairs in P. ternata that differed between heat-stress and room-temperature conditions. Transcriptome analysis revealed extensive reprogramming of 4,960 genes across various categories, predominantly associated with cellular and metabolic processes, responses to stimuli, biological regulation, cell parts, organelles, membranes, and catalytic and binding activities. miRNAome sequencing identified 1,597 known/conserved miRNAs that were differentially expressed between the two test conditions. According to the analysis, genes and miRNAs associated with the regulation of transcription, DNA template, transcription factor activity, and sequence-specific DNA binding pathways may play a major role in the resistance to heat stress in P. ternata. Integrated analysis of the transcriptome and miRNAome expression data revealed 41 high-confidence miRNA-mRNA pairs, forming 25 modules. MYB-like proteins and calcium-responsive transcription coactivators may play an integral role in heat-stress resistance in P. ternata. Additionally, the candidate genes and miRNAs were subjected to quantitative real-time polymerase chain reaction to validate their expression patterns. These results offer a foundation for future studies exploring the mechanisms and critical genes involved in heat-stress resistance in P. ternata.

An Intrinsic Stable Layered Oxide Cathode for Practical Sodium-Ion Battery: Solid Solution Reaction, Near-Zero-Strain and Marvelous Water Stability.

Non-aqueous solvents, in particular N,N-dimethylaniline (NMP), are widely applied for electrode fabrication since most sodium layered oxide cathode materials are readily damaged by water molecules. However, the expensive price and poisonousness of NMP unquestionably increase the cost of preparation and post-processing. Therefore, developing an intrinsically stable cathode material that can implement the water-soluble binder to fabricate an electrode is urgent. Herein, a stable nanosheet-like Mn-based cathode material is synthesized as a prototype to verify its practical applicability in sodium-ion batteries (SIBs). The as-prepared material displays excellent electrochemical performance and remarkable water stability, and it still maintains a satisfactory performance of 79.6% capacity retention after 500 cycles even after water treatment. The in situ X-ray diffraction (XRD) demonstrates that the synthesized material shows an absolute solid-solution reaction mechanism and near-zero-strain. Moreover, the electrochemical performance of the electrode fabricated with a water-soluble binder shows excellent long-cycling stability (67.9% capacity retention after 500 cycles). This work may offer new insights into the rational design of marvelous water stability cathode materials for practical SIBs.

NLRP3 activation in neutrophils induces lethal autoinflammation, liver inflammation, and fibrosis.

Sterile inflammation is a central element in liver diseases. The immune response following injurious stimuli involves hepatic infiltration of neutrophils and monocytes. Neutrophils are major effectors of liver inflammation, rapidly recruited to sites of inflammation, and can augment the recruitment of other leukocytes. The NLRP3 inflammasome has been increasingly implicated in severe liver inflammation, fibrosis, and cell death. In this study, the role of NLRP3 activation in neutrophils during liver inflammation and fibrosis was investigated. Mouse models with neutrophil-specific expression of mutant NLRP3 were developed. Mutant mice develop severe liver inflammation and lethal autoinflammation phenocopying mice with a systemic expression of mutant NLRP3. NLRP3 activation in neutrophils leads to a pro-inflammatory cytokine and chemokine profile in the liver, infiltration by neutrophils and macrophages, and an increase in cell death. Furthermore, mutant mice develop liver fibrosis associated with increased expression of pro-fibrogenic genes. Taken together, the present work demonstrates how neutrophils, driven by the NLRP3 inflammasome, coordinate other inflammatory myeloid cells in the liver, and propagate the inflammatory response in the context of inflammation-driven fibrosis.

Bone Marrow Transplantation Rescues Monocyte Recruitment Defect and Improves Cystic Fibrosis in Mice.

Cystic fibrosis (CF) is an inherited life-threatening disease accompanied by repeated lung infections and multiorgan inflammation that affects tens of thousands of people worldwide. The causative gene, cystic fibrosis transmembrane conductance regulator (CFTR), is mutated in CF patients. CFTR functions in epithelial cells have traditionally been thought to cause the disease symptoms. Recent work has shown an additional defect: monocytes from CF patients show a deficiency in integrin activation and adhesion. Because monocytes play critical roles in controlling infections, defective monocyte function may contribute to CF progression. In this study, we demonstrate that monocytes from CFTRΔF508 mice (CF mice) show defective adhesion under flow. Transplanting CF mice with wild-type (WT) bone marrow after sublethal irradiation replaced most (60-80%) CF monocytes with WT monocytes, significantly improved survival, and reduced inflammation. WT/CF mixed bone marrow chimeras directly demonstrated defective CF monocyte recruitment to the bronchoalveolar lavage and the intestinal lamina propria in vivo. WT mice reconstituted with CF bone marrow also show lethality, suggesting that the CF defect in monocytes is not only necessary but also sufficient to cause disease. We also show that monocyte-specific knockout of CFTR retards weight gains and exacerbates dextran sulfate sodium-induced colitis. Our findings show that providing WT monocytes by bone marrow transfer rescues mortality in CF mice, suggesting that similar approaches may mitigate disease in CF patients.

Recalled age of myopia onset may predict risk of high adult myopia in Chinese adults.

INTRODUCTION: This study aimed to investigate the relationship between age of myopia onset and high myopia and to explore if age of onset mediated the associations of high myopia with parental myopia and time spent on electronics. METHODS: This cross-sectional study enrolled 1118 myopic patients aged 18 to 40. Information was obtained via a detailed questionnaire. Multivariable logistic regression and linear regression models were utilized to assess age of onset in relation to high myopia and spherical equivalent refractive error, respectively. Structural equation models examined the mediated effect of onset age on the association between parental myopia, time spent on electronics and high myopia. RESULTS: An early age at myopia onset was negatively correlated with spherical equivalent refractive power. Subjects who developed myopia before the age of 12 were more likely to suffer from high myopia than those who developed myopia after the age of 15. Age of myopia onset was the strongest predictor of high myopia, with an area under the curve (AUC) in Receiver Operator Characteristic (ROC) analysis of 0.80. Additionally, age of myopia onset served as a mediator in the relationships between parental myopia, electronic device usage duration, and the onset of high myopia in adulthood. CONCLUSIONS: Age of myopia onset might be the single best predictor for high myopia, and age at onset appeared to mediate the associations of high myopia with parental myopia and time spent on electronics.

Transcriptome Profiling Reveals Differential Gene Expression during the Process of Microtuber Formation in Pinellia ternata.

Using petiole material as explants and directly inducing the formation of microtubers without going through the callus stage is an essential way to rapidly expand scarce medical plants such as Pinellia ternata. However, the early molecular mechanism underlying the formation of the microtuber is largely elusive. Here, we conducted cytology and dynamic transcriptome analyses of inchoate microtubers in Pinellia explants and identified 1092 differentially expressed genes after their cultivation in vitro for 0, 5, and 15 days. Compared with 0 day, the number and size of the microtuber cells were larger at 5 and 15 days of culture. Detailed categorization revealed that the differentially expressed genes were mainly related to responses to stimulus, biological regulation, organelles, membranes, transcription factor activity, and protein binding. Further analysis revealed that the microtuber at different incubation days exhibited quite a difference in both hormone signaling pathway transduction and the regulation pattern of transcription factors. Therefore, this study contributes to a better understanding of the early molecular regulation during the formation of the microtuber and provides new insights for the study of the rapid expansion of P. ternata and other medical plants.

Tumor necrosis factor ligand-related molecule 1A maintains blood-retinal barrier via modulating SHP-1-Src-VE-cadherin signaling in diabetic retinopathy.

An impaired blood-retinal barrier (BRB) leads to diabetic macular edema (DME), which is a major complication of Diabetic retinopathy (DR). Mediators such as inflammation cause BRB breakdown. However, the explicit mechanism of its disruption is largely unknown. In this study, we identified tumor necrosis factor ligand-related molecule 1A (TL1A) as a crucial factor which protect retinal endothelial cells integrity in DR. By providing both human and mouse data, we show that TL1A is significantly decreased in the retinas of DME patients and diabetic rodents. We further demonstrate that the loss of TL1A accelerated diabetes-induced retinal barrier breakdown. TL1A supplementation protects the diabetic retina against BRB breakdown. Mechanistically, TL1A stabilize intracellular junctions and protect vascular integrity by blocking SHP1-Src-regulated VE-cadherin phosphorylation. Collectively, our findings reveal that loss of TL1A in the retina leads to increased vascular permeability in DR, and that TL1A treatment is of potential therapeutic interest for the treatment of DME.

Patrolling Monocytes Control NK Cell Expression of Activating and Stimulatory Receptors to Curtail Lung Metastases.

The role of nonclassical, patrolling monocytes in lung tumor metastasis and their functional relationships with other immune cells remain poorly defined. Contributing to these gaps in knowledge is a lack of cellular specificity in commonly used approaches for depleting nonclassical monocytes. To circumvent these limitations and study the role of patrolling monocytes in melanoma metastasis to lungs, we generated C57BL/6J mice in which the Nr4a1 superenhancer E2 subdomain is ablated (E2 -/- mice). E2 -/- mice lack nonclassical patrolling monocytes but preserve classical monocyte and macrophage numbers and functions. Interestingly, NK cell recruitment and activation were impaired, and metastatic burden was increased in E2 -/-mice. E2 -/- mice displayed unchanged "educated" (CD11b+CD27+) and "terminally differentiated" (CD11b+CD27-) NK cell frequencies. These perturbations were accompanied by reduced expression of stimulatory receptor Ly49D on educated NK cells and increased expression of inhibitory receptor NKG2A/CD94 on terminally differentiated NK cells. Thus, our work demonstrates that patrolling monocytes play a critical role in preventing lung tumor metastasis via NK cell recruitment and activation.

Association of Physical Activity with Retinal Thickness and Vascular Structure in Elderly Chinese Population.

INTRODUCTION: We aimed to assess the association of physical activity (PA) with retinal thickness and vascular structure in an elderly Chinese population. METHODS: This study enrolled 220 retirees aged 50 years and above from Tianjin University of Sport, China. PA data gathered through the International Physical Activity Questionnaires were computed for metabolic equivalent of task-minutes per week. All participants underwent full ophthalmic examination including optical coherence tomography angiography (OCTA). Multiple linear regression analyses were used to evaluate the association of PA with retinal thickness and vascular structure. RESULTS: A high amount of total PA was associated with smaller size of foveal avascular zone (FAZ) (high vs. low: area, ß=-0.04; circumference ß=-0.14) and greater central vessel (VD) (ß=1.04) and perfusion densities (PD) (ß=0.02). For domain-specific PA, participants with high and moderate recreational PA levels were found to have greater central VDs and PDs. Non-leisure activities demonstrated negative relationship with FAZ perimeter ratio (moderate vs. low: ß=-0.08; high vs. low: ß=-0.13) and, counter-intuitively, negative relation with VDs measured at the inner (high vs. low: ß=-0.98) and outer retinal layers (high vs. low: ß=-0.38). Additionally, higher levels of total PA were related to increased macular fovea thickness and average thickness of retinal nerve fiber layer. CONCLUSIONS: High PA level, particularly recreational PA, was associated with smaller FAZ and greater VD and PD in senior adults. Non-leisure time PA might not confer the same health benefits as leisure time PA. Our data supports a possible protective role of recreational PA in the retina against microvascular changes.

Clinical efficacy of motor imagery therapy based on fNIRs technology in rehabilitation of upper limb function after acute cerebral infarction.

Objective: To investigate the efficacy of motor imagery therapy (MIT) based on functional near-infrared spectroscopy (fNIRs) technology in rehabilitation of upper limb function after cerebral infarction, so as to provide guidance for clinical practice. Methods: A total of 84 patients with upper limb dysfunction after acute cerebral infarction admitted to Wuhan Puren Hospital from January 2020 to January 2021 were included in this study and randomly divided into two groups based on random number table method: experimental group and control group, with 42 cases in each group. Both groups were given active symptomatic treatment. The control group received conventional exercise rehabilitation, while the experimental group also received MIT based on fNIRs technology in addition to the treatment method adopted by the control group, lasting for eight weeks. The simplified Fugl-Meyer scale was utilized to evaluate the recovery of upper limb function, and the changes of Oxy-Hb and Deoxy-Hb concentrations in the frontal area of brain tissue were measured to evaluate the total effective rate of clinical rehabilitation. Results: At four and eight weeks of treatment, the Fugl-Meyer scores of the two groups were significantly higher than those before treatment (P<0.05), and those in experimental group were significantly higher than those in control group (P<0.05), with no significant difference before treatment (P>0.05). After treatment, Oxy-Hb concentration in the experimental group was higher than that in the control group (P<0.05), while Deoxy-Hb concentration was lower than that in the control group, with a statistical significance (P<0.05). The total effective rate of rehabilitation in the experimental group was 88.10%, which was significantly higher than 73.81% in the control group (P<0.05). Conclusion: Motor imagery therapy (MIT) Based on fNIRs technology has important clinical value in rehabilitation of upper limb function after cerebral infarction and is superior to conventional exercise rehabilitation alone, boasting a variety of effects, such as improving the curative effect, ameliorating blood oxygen in brain tissue, and promoting the rehabilitation of upper limb function of patients.

Silicon nanostructure-doped polymer/nematic liquid crystal composites for low voltage-driven smart windows.

In this work, two silicon nanostructures were doped into polymer/nematic liquid crystal composites to regulate the electric-optical performance. Commercial SiO2nanoparticles and synthesized thiol polyhedral oligomeric silsesquioxane (POSS-SH) were chosen as the dopants to afford the silicon nanostructures. SiO2nanoparticles were physically dispersed in the composites and the nanostructure from POSS-SH was implanted into the polymer matrix of the composites via photoinduced thiol-ene crosslinking. Scanning electron microscopy results indicated that the implantation of POSS microstructure into the polymer matrix was conducive to obtaining the uniform porous polymer microstructures in the composites while the introduction of SiO2nanoparticles led to the loose and heterogeneous polymer morphologies. The electric-optical performance test results also demonstrated that the electric-optical performance regulation effect of POSS microstructure was more obvious than that of SiO2nanoparticles. The driving voltage was reduced by almost 80% if the concentration of POSS-SH in the composite was nearly 8 wt% and the sample could be completely driven by the electric field whose voltage was lower than the safe voltage for continuous contact (24 V). This work could provide a creative approach for the regulation of electric-optical performance for polymer/nematic liquid crystal composites and the fabrication of low voltage-driven PDLC films for smart windows.

[Analysis of shading on DNA methylation by MSAP in Pinellia ternata].

Pinellia ternata is a medicinal herb of Araceae, and its tubers are used as medicines. It is a common Chinese herbal medicine in China and has a large market demand. When exposing to strong light intensity and high temperature during the growth process, P. ternata withers in a phenomenon known as "sprout tumble", which largely limits tuber production. Shade can effectively delay sprout tumble formation and increase its yield, however the relevant regulation mechanism is unclear. DNA methylation, as a self-modifying response to environmental changes, is often involved in the regulation of plant growth and development. In this study, P. ternata grown under natural light and 90% shading were selected as the control group and the experimental group for genomic DNA methylation analysis by using methylate sensitive amplification polymorphism(MSAP). The results showed that a total of 617 loci were detected with 20 pairs of primers, of which 311 were in the natural light group and 306 in the shading group. The methylation sites in the light and shading groups accounted for 58.2% and 71.57%, respectively, and the methylation ratios in the methylation sites were 27.65% and 29.41%, respectively, indicating that shading significantly induced the genome DNA methylation of P. ternata. Compared to the natural light group, shading promoted 32.51% of the genes methylation, while inducing 16.25% gene demethylation. This study reveals the DNA methylation variation of P. ternata under shading conditions, which lays a preliminary theoretical foundation for further analysis of the mechanism of shading regulation of P. ternata growth from epigenetic level.

Manipulating Layered P2@P3 Integrated Spinel Structure Evolution for High-Performance Sodium-Ion Batteries.

Structural evolution of the cathode during cycling plays a vital role in the electrochemical performance of sodium-ion batteries. A strategy based on engineering the crystal structure coupled with chemical substitution led to the design of the layered P2@P3 integrated spinel oxide cathode Na0.5 Ni0.1 Co0.15 Mn0.65 Mg0.1 O2 , which shows excellent sodium-ion half/full battery performance. Combined analyses involving scanning transmission electron microscopy with atomic resolution as well as in situ synchrotron-based X-ray absorption spectra and in situ synchrotron-based X-ray diffraction patterns led to visualization of the inherent layered P2@P3 integrated spinel structure, charge compensation mechanism, structural evolution, and phase transition. This study provides an in-depth understanding of the structure-performance relationship in this structure and opens up a novel field based on manipulating structural evolution for the design of high-performance battery cathodes.

Deciphering an Abnormal Layered-Tunnel Heterostructure Induced by Chemical Substitution for the Sodium Oxide Cathode.

Demands for large-scale energy storage systems have driven the development of layered transition-metal oxide cathodes for room-temperature rechargeable sodium ion batteries (SIBs). Now, an abnormal layered-tunnel heterostructure Na0.44 Co0.1 Mn0.9 O2 cathode material induced by chemical element substitution is reported. By virtue of beneficial synergistic effects, this layered-tunnel electrode shows outstanding electrochemical performance in sodium half-cell system and excellent compatibility with hard carbon anode in sodium full-cell system. The underlying formation process, charge compensation mechanism, phase transition, and sodium-ion storage electrochemistry are clearly articulated and confirmed through combined analyses of in situ high-energy X-ray diffraction and ex situ X-ray absorption spectroscopy as well as operando X-ray diffraction. This crystal structure engineering regulation strategy offers a future outlook into advanced cathode materials for SIBs.

Full-length transcriptome analysis of shade-induced promotion of tuber production in Pinellia ternata.

BACKGROUND: Pinellia ternata is native to China and has been used as a traditional herb due to its antiemetic, antitussive, analgesic, and anxiolytic effects. When exposed to strong light intensity and high temperature during the reproductive growth process, P. ternata withers in a phenomenon known as "sprout tumble", which largely limits tuber production. Shade was previously found to delay sprout tumble formation (STF); however, no information exists regarding this process at the molecular level. Hence, we determined the genes involved in tuber development and STF in P. ternata. RESULTS: Compared to that with natural sun-light (control), shade significantly induced chlorophyll accumulation, increased chlorophyll fluorescence parameters including initial fluorescence, maximal fluorescence, and qP, and dramatically repressed chlorophyll a:b and NPQ. Catalase (CAT) activity was largely induced by shade, and tuber products were largely increased in this environment. Transcriptome profiles of P. ternata grown in natural sun-light and shaded environments were analyzed by a combination of next generation sequencing (NGS) and third generation single-molecule real-time (SMRT) sequencing. Corrections of SMRT long reads based on NGS short reads yielded 136,163 non-redundant transcripts, with an average N50 length of 2578 bp. In total, 6738 deferentially-expressed genes (DEGs) were obtained from the comparisons, specifically D5S vs D5CK, D20S vs D20CK, D20S vs D5S, and D20CK vs D5CK, of which, 6384 DEGs (94.8%) were generated from the D20S vs D20CK comparison. Gene annotation and functional analyses revealed that these genes were related to auxin signal transduction, polysaccharide and sugar metabolism, phenylpropanoid biosynthesis, and photosynthesis. Moreover, the expression of genes enriched in photosynthesis appeared to be significantly altered by shade. The expression patterns of 16 candidate genes were consistent with changes in their transcript abundance as identified by RNA-Seq, and these might contribute to STF and tuber production. CONCLUSION: The full-length transcripts identified in this study have provided a more accurate depiction of P. ternata gene transcription. Further, we identified potential genes involved in STF and tuber growth. Such data could serve as a genetic resource and a foundation for further research on this important traditional herb.

Transcriptional and physiological analyses of short-term Iron deficiency response in apple seedlings provide insight into the regulation involved in photosynthesis.

BACKGROUND: Iron (Fe) is an essential micronutrient for plants. Utilization of Fe deficiency-tolerant rootstock is an effective strategy to prevent Fe deficiency problems in fruit trees production. Malus halliana is an apple rootstock that is resistant to Fe deficiency; however, few molecular studies have been conducted on M. halliana. RESULTS: To evaluate short-term molecular response of M. halliana leaves under Fe deficiency condition, RNA sequencing (RNA-Seq) analyses were conducted at 0 (T1), 0.5 (T2) and 3 d (T3) after Fe-deficiency stress, and the timepoints were determined with a preliminary physiological experiment. In all, 6907, 5328, and 3593 differentially expressed genes (DEGs) were identified in pairs of T2 vs. T1, T3 vs. T1, and T3 vs. T2. Several of the enriched DEGs were related to heme binding, Fe ion binding, thylakoid membranes, photosystem II, photosynthesis-antenna protein, porphyrin and chlorophyll metabolism and carotenoid biosynthesis under Fe deficiency, which suggests that Fe deficiency mainly affects the photosynthesis of M. halliana. Additionally, we found that Fe deficiency induced significant down-regulation in genes involved in photosynthesis at T2 when seedlings were treated with Fe-deficient solution for 0.5 d, indicating that there was a rapid response of M. halliana to Fe deficiency. A strong up-regulation of photosynthesis genes was detected at T3, which suggested that M. halliana was able to recover photosynthesis after prolonged Fe starvation. A similar expression pattern was found in pigment regulation, including genes for coding chlorophyllide a oxygenase (CAO), ß-carotene hydroxylase (ß-OHase), zeaxanthin epoxidase (ZEP) and 9-cis-epoxycarotenoid dioxygenase (NCED). Our results suggest that pigment regulation plays an important role in the Fe deficiency response. In addition, we verified sixteen genes related to photosynthesis-antenna protein, porphyrin and chlorophyll metabolism and carotenoid biosynthesis pathways using quantitative real-time PCR (qRT-PCR) to ensure the accuracy of transcriptome data. Photosynthetic parameters, Chl fluorescence parameters and the activity of Chlase were also determined. CONCLUSIONS: This study broadly characterizes a molecular mechanism in which pigment and photosynthesis-related regulations play indispensable roles in the response of M. halliana to short-term Fe deficiency and provides a basis for future analyses of the key genes involved in the tolerance of Fe deficiency.