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Soybean is a typical short-day crop, and most commercial soybean cultivars are restricted to a relatively narrow range of latitudes due to photoperiod sensitivity. Photoperiod sensitivity hinders the utilization of soybean germplasms across geographical regions. When grown in temperate regions, tropical soybean responds to prolonged day length by increasing the vegetative growth phase and delaying flowering and maturity, which often pushes the harvest window past the first frost date. In this study, we used CRISPR/LbCas12a to edit a North American subtropical soybean cultivar named 06KG218440 that belongs to maturity group 5.5. By designing one gRNA to edit the nuclear localization signal (NLS) regions of both E1 and E1Lb, we created a series of new germplasms with shortened flowering time and time to maturity and determined their favourable latitudinal zone for cultivation. The novel partial function alleles successfully achieve yield and early maturity trade-offs and exhibit good agronomic traits and high yields in temperate regions. This work offers a straightforward editing strategy to modify subtropical and tropical soybean cultivars for temperate growing regions, a strategy that could be used to enrich genetic diversity in temperate breeding programmes and facilitate the introduction of important crop traits such as disease tolerance or high yield.
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Edição de Genes , Glycine max , Glycine max/genética , Glycine max/crescimento & desenvolvimento , Glycine max/metabolismo , Edição de Genes/métodos , Sinais de Localização Nuclear , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Sistemas CRISPR-CasRESUMO
The control of flowering time in maize is crucial for reproductive success and yield, and it can be influenced by environmental stresses. Using the approaches of Ac/Ds transposon and transposable element amplicon sequencing techniques, we identified a Ds insertion mutant in the ZmPRR37 gene. The Ds insertion showed a significant correlation with days to anthesis. Further research indicated that ZmPRR37-CR knockout mutants exhibited early flowering, whereas ZmPRR37-overexpression lines displayed delayed flowering compared to WT under long-day (LD) conditions. We demonstrated that ZmPRR37 repressed the expression of ZmNF-YC2 and ZmNF-YA3 to delay flowering. Association analysis revealed a significant correlation between flowering time and a SNP2071-C/T located upstream of ZmPRR37. The SNP2071-C/T impacted the binding capacity of ZmELF6 to the promoter of ZmPRR37. ZmELF6 also acted as a flowering suppressor in maize under LD conditions. Notably, our study unveiled that ZmPRR37 can enhance salt stress tolerance in maize by directly regulating the expression of ABA-responsive gene ZmDhn1. ZmDhn1 negatively regulated maize salt stress resistance. In summary, our findings proposed a novel pathway for regulating photoperiodic flowering and responding to salt stress based on ZmPRR37 in maize, providing novel insights into the integration of abiotic stress signals into floral pathways.
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Flores , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Flores/fisiologia , Zea mays/genética , Zea mays/metabolismo , Fotoperíodo , Regiões Promotoras Genéticas , Regulação da Expressão Gênica de Plantas/genéticaRESUMO
Drought is a major abiotic stress that limits maize production worldwide. Therefore, it is of great importance to improve drought tolerance in crop plants for sustainable agriculture. In this study, we examined the roles of Cys2 /His2 zinc-finger-proteins (C2H2-ZFPs) in maize's drought tolerance as C2H2-ZFPs have been implicated for plant stress tolerance. By subjecting 150 Ac/Ds mutant lines to drought stress, we successfully identified a Ds-insertion mutant, zmc2h2-149, which shows increased tolerance to drought stress. Overexpression of ZmC2H2-149 in maize led to a decrease in both drought tolerance and crop yield. DAP-Seq, RNA-Seq, Y1H and LUC assays additionally showed that ZmC2H2-149 directly suppresses the expression of a positive drought tolerance regulator, ZmHSD1 (hydroxysteroid dehydrogenase 1). Consistently, the zmhsd1 mutants exhibited decreased drought tolerance and grain yield under water deficit conditions compared to their respective wild-type plants. Our findings thus demonstrated that ZmC2H2-149 can regulate ZmHSD1 for drought stress tolerance in maize, offering valuable theoretical and genetic resources for maize breeding programmes that aim for improving drought tolerance.
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Resistência à Seca , Zea mays , Zea mays/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Secas , Estresse Fisiológico/genética , Regulação da Expressão Gênica de PlantasRESUMO
Drought, as a primary environmental factor, imposes significant constraints on developmental processes and productivity of plants. PHDs were identified as stress-responsive genes in a wide range of eukaryotes. However, the regulatory mechanisms governing PHD genes in maize under abiotic stress conditions are still largely unknown and require further investigation. Here, we identified a mutant, zmvil2, in the EMS mutant library with a C to T mutation in the exon of the Zm00001d053875 (VIN3-like protein 2, ZmVIL2), resulting in premature termination of protein coding. ZmVIL2 belongs to PHD protein family. Compared to WT, zmvil2 mutant exhibited increased sensitivity to drought stress. Consistently, overexpression of ZmVIL2 enhances drought resistance in maize. Y2H, BiFC, and Co-IP experiments revealed that ZmVIL2 directly interacts with ZmFIP37 (FKBP12-interacting protein of 37). zmfip37 knockout mutants also exhibit decreased drought tolerance. Interestingly, we demonstrated that ZmABF4 directly binds to the ZmVIL2 promoter to enhance its activity in yeast one hybrid (Y1H), electrophoretic mobility shift assay (EMSA) and dual luciferase reporter assays. Therefore, we uncovered a novel model ZmABF4-ZmVIL2/ZmFIP37 that promotes drought tolerance in maize. Overall, these findings have enriched the knowledge of the functions of PHD genes in maize and provides genetic resources for breeding stress-tolerant maize varieties.
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BACKGROUND: A large number of psychological consequences including sleep health emerged during the 2019 Coronavirus disease (COVID-19) pandemic. Sleep patterns in toddlers are vulnerable to negative environmental exposures, however, very few studies on this topic have been published so far. OBJECTIVES: In this paper, we aimed to investigate the sleep patterns and associated factors in toddlers from China confined at home in the context of COVID-19 pandemic. METHODS: From April to November 2021, a convenience sample of 493 parents of young children aged (12-35 months) were surveyed from Fuzhou, Sanming, Quanzhou, Nanping, and Longyan cities in the Fujian Province, China. A cross-sectional survey was conducted via Electronic questionnaires to collect parent and child social-demographic characteristics. The Brief Infant Sleep Questionnaire (BISQ) was used to collect data on sleep practices, sleep duration and patterns, as well as the number of nocturnal awaking . RESULTS: The mean age of toddlers was 2.11 years old, and 52.54% (259/493) were males. Among the 493 toddlers' sleep patterns, 331(67.1%) initiated sleep accompanied by parents, 67(13.6%) slept independently, 59 (12.0%) were breast fed/bottle fed to initiate sleep, 27 (5.5%) were held and 9 (1.8%) rocked. The clear longitudinal association between the duration of night-time sleep, the frequency of nighttime awakenings, and various sleep patterns remains clear (p < 0.05). Multiple linear regression analysis indicated that sleep initiation with bottle-feeding/breast-feeding and rocked significantly increased the frequency of nighttime awakenings and reduced the duration of nighttime sleep (p < 0.05), as held was dramatically only for increasing the number of nighttime awakenings (p < 0.05). Multi-variate logistic regression analysis demonstrated that toddlers with severe sleep difficulties had a higher probability of being rocked to initiate sleep (p < 0.05). Conversely, young children with minor sleep problems were more apt to be in bed alone to initiate sleep (p < 0.05). CONCLUSIONS: During the COVID-19 pandemic, most infants and toddlers initiated sleep accompanied by parents and tend to have electronic media exposure before bedtime. Increased waking at night may be associated with sleep initiation with breast-feeding/bottle-feeding. Therefore, pediatric practitioners in primary community hospitals should pay attention to the education and promotion of sleep hygiene and parenting knowledge of young children to avoid the formation of poor sleep hygiene habits.
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COVID-19 , Qualidade do Sono , Humanos , Masculino , Feminino , China/epidemiologia , Lactente , Estudos Transversais , Pré-Escolar , COVID-19/epidemiologia , Sono , Inquéritos e Questionários , Pais , Aleitamento Materno/estatística & dados numéricosRESUMO
In addressing the ramifications of climate change, the shipping industry, reliant on energy, has been integrated into the Emissions Trading System (ETS). This study utilizes the quantile connectedness model to investigate the information spillover mechanisms and extreme time-varying interconnections among carbon, energy, and shipping markets. Whether climate policy uncertainty drives the extreme interconnections is also discussed during both pre- and post-Paris Agreement periods, by using GARCH-MIDAS model. The empirical findings underscore the following key points: (i) the systemic connectedness is highly sensitive to market conditions and major events, increasing significantly under extreme market conditions; (ii) following the implementation of the Paris Agreement, an elevated level of informational interdependence has manifested between the carbon market and the energy and shipping sectors; (iii) the information transfer mechanism between carbon and shipping sectors creates direct and indirect spillover paths, with crude oil market mediating the indirect path; (iv) climate policy uncertainty greatly affects the extreme time-varying interconnections, and this impact has decreased after the Paris Agreement came into effect. These results offer valuable insights for market policymakers and shipping companies in achieving a balance between carbon emission reduction and shipping business, particularly amidst heightened climate policy uncertainty.
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Carbono , Mudança Climática , Incerteza , Modelos TeóricosRESUMO
To reveal differences in arsenic (As) accumulation among indica rice cultivars and assess the human health risks arising from inorganic arsenic (iAs) intake via rice consumption, a total of 320 field indica rice samples and corresponding soil samples were collected from Fujian Province in China. The results showed that available soil As (0.03 to 3.83 mg/kg) showed a statistically significant positive correlation with total soil As (0.10 to 19.45 mg/kg). The inorganic As content in brown rice was between 0.001 and 0.316 mg/kg. Among the cultivars, ten brown rice samples (3.13%) exceeded the maximum contaminant level (MCL) of iAs in food of 0.2 mg/kg in China. The estimated daily intake (EDI) and calculated individual incremental lifetime cancer risk (ILCR) ranged from 0.337 µg/day to 106.60 µg/day and from 8.18 × 10-6 to 2.59 × 10-3, respectively. Surprisingly, the average EDI and the EDIs of 258 (80.63%) brown rice samples were higher than the maximum daily intake (MDI) of 10 µg/day in drinking water as set by the National Research Council. The mean ILCR associated with iAs was 54.3 per 100,000, which exceeds the acceptable upper limit (AUL) of 10 per 100,000 set by the USEPA. Notably, the cultivars Y-Liang-You 1 and Shi-Ji 137 exhibited significantly higher mean ILCRs compared to the AUL and other cultivars, indicating that they pose more serious cancer risks to the local population. Finally, this study demonstrated that the cultivars Yi-Xiang 2292 and Quan-Zhen 10 were the optimal cultivars to mitigate risks associated with iAs to human health from rice consumption.
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Arsênio , Neoplasias , Oryza , Humanos , Oryza/genética , Monitoramento Ambiental , Medição de Risco , Genótipo , SoloRESUMO
OBJECTIVE: Bone metabolism can be influenced by a range of factors. We selected children with self-limited epilepsy with centrotemporal spikes (SeLECTS) and lifestyles similar to those of healthy children to control for the confounding factors that may influence bone metabolism. We aimed to identify the specific effects of epilepsy and/or anti-seizure medications (ASMs) on bone metabolism. METHODS: Patients with SeLECTS were divided into an untreated group and a monotherapy group, and the third group was a healthy control group. We determined the levels of various biochemical markers of bone metabolism, including procollagen type I nitrogenous propeptide (PINP), alkaline phosphatase (ALP), osteocalcin (OC), collagen type I cross-linked C-telopeptide (CTX), calcium, magnesium, phosphorus, parathyroid hormone (PTH), and vitamin D3 (VD3 ). RESULTS: A total of 1487 patients (from 19 centers) were diagnosed with SeLECTS; 1032 were analyzed, including 117 patients who did not receive any ASMs (untreated group), 643 patients who received only one ASM (monotherapy group), and 272 children in the healthy control group. Except for VD3 , other bone metabolism of the three groups were different (p < .001). Bone metabolism was significantly lower in the untreated group than the healthy control group (p < .05). There were significant differences between the monotherapy and healthy control group in the level of many markers. However, when comparing the monotherapy and untreated groups, the results were different; oxcarbazepine, levetiracetam, and topiramate had no significant effect on bone metabolism. Phosphorus and magnesium were significantly lower in the valproic acid group than the untreated group (adjusted p < .05, Cliff's delta .282-.768). CTX was significantly higher in the lamotrigine group than in the untreated group (adjusted p = .012, Cliff's delta = .316). SIGNIFICANCE: Epilepsy can affect many aspects of bone metabolism. After controlling epilepsy and other confounders that affect bone metabolism, we found that the effects of ASMs on bone metabolism differed. Oxcarbazepine, levetiracetam, and topiramate did not affect bone metabolism, and lamotrigine corrected some of the abnormal markers of bone metabolism in patients with epilepsy.
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A palladium-catalyzed multicomponent cascade reaction of aryl iodides, oxanorbornadiene, and diborns to access (Z)-alkenylborons is reported. This transformation proceeds through the sequential carbopalladation/boronation/retro-Diels-Alder domino reaction. The oxanorbornadiene used in this reaction serves as an acetylene surrogate, which is generated via a retro-Diels-Alder reaction. Such a stereoselective and scalable approach has a wide range of functional group tolerance and good substrate universality.
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BACKGROUND: Overhydrated hereditary stomatocytosis (OHSt) is a rare disorder characterized by abnormalities in erythrocytic volume homeostasis. Early and accurate diagnosis is essential for appropriate management and genetic counseling. METHODS: We present the case of a child with beta-thalassemia and a history of multiple blood transfusions. Clinical presentation, laboratory findings, and genetic testing were reviewed. Peripheral blood smear examination and genetic analysis were performed. RESULTS: The patient was admitted with severe anemia, and peripheral blood smear examination revealed the presence of up to 50% stomatocytes. Laboratory investigations showed abnormalities in red blood cell parameters, including decreased hemoglobin levels and increased mean corpuscular volume. Genetic testing identified a heterozygous mutation in the RHAG gene, confirming the diagnosis of OHSt. The presence of stomatocytes in the peripheral blood smear was transient, correlating with episodes of hemolysis and its control.
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Anemia Hemolítica Congênita , Talassemia beta , Criança , Humanos , Talassemia beta/complicações , Talassemia beta/diagnóstico , Talassemia beta/genética , Anemia Hemolítica Congênita/diagnóstico , Anemia Hemolítica Congênita/genética , Eritrócitos , Eritrócitos AnormaisRESUMO
Insufficiency of the small saphenous vein causes 15% of varicose veins in the lower extremities. Endovenous ablation for the treatment of small saphenous vein varices has become a trend, and an increasing number of studies have reported the effects of different types of endovenous ablation in patients with small saphenous varicose veins. The purpose of this systematic review is to summarize the results of existing studies on endovenous ablation for the treatment of small saphenous varicose veins, compare its role and efficacy, and provide insights into the future development of endovenous ablation for treating small saphenous varicose veins. A systematic review of literature published from January 1, 2002 to January 1, 2022 was conducted from PubMed, Embase, and China Academic Journals full-text databases. The pre-determined inclusion criteria were clinical literature of endovenous ablation for treating small saphenous varicose veins. Keywords included "ablation", "small saphenous vein", "lesser saphenous vein", "short saphenous vein", "xiaoyinjingmai" and "xiaorong". Of the 506 articles screened, 33 articles were included in this review: 19 articles were related to endovenous laser ablation, five were related to mechanochemical ablation, seven were related to radiofrequency ablation, and two were related to both endovenous laser ablation and radiofrequency ablation. The anatomical success rate of endovenous laser ablation, radiofrequency ablation, and mechanochemical ablation were 94.3%, 96.0%, and 88.1%, respectively, and the heterogeneities were all moderate. Most of the current studies are of a low-quality level of research. Hence, long-term follow-up studies and large-scale randomized controlled trials are required to obtain high-quality evidence. Although the gold standard for the treatment of small saphenous vein insufficiency remains unclear, endovenous ablation is still the recommended method.
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Terapia a Laser , Varizes , Insuficiência Venosa , Humanos , Veia Safena/diagnóstico por imagem , Veia Safena/cirurgia , Varizes/diagnóstico por imagem , Varizes/cirurgia , Escleroterapia/efeitos adversos , Escleroterapia/métodos , Terapia a Laser/efeitos adversos , Terapia a Laser/métodos , China , Resultado do Tratamento , Insuficiência Venosa/diagnóstico por imagem , Insuficiência Venosa/cirurgiaRESUMO
OBJECTIVE: To explore the clinical phenotype and genetic features of two children with MEGDEL syndrome due to variants of the SERAC1 gene. METHODS: Two children who had presented at the Fujian Medical University Union Hospital respectively on July 14, 2020 and July 28, 2018 were selected as the study subjects. Clinical features and results of genetic testing were retrospectively analyzed. RESULTS: Both children had featured developmental delay, dystonia and sensorineural deafness, along with increased urine 3-methylglutaric acid levels. Magnetic resonance imaging revealed changes similar to Leigh-like syndrome. Gene sequencing revealed that both children have harbored pathogenic compound heterozygous variants of the SERAC1 gene, including c.1159C>T and c.442C>T in child 1, and c.1168C>T and exons 4~9 deletion in child 2. CONCLUSION: Children with MEGDEL syndrome due to SERAC1 gene variants have variable clinical genotypes. Delineation of its clinical characteristics and typical imaging changes can facilitate early diagnosis and treatment. Discovery of the novel variants has also enriched the spectrum of SERAC1 gene variants.
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Distonia , Perda Auditiva Neurossensorial , Erros Inatos do Metabolismo , Humanos , Estudos Retrospectivos , Perda Auditiva Neurossensorial/genética , Hidrolases de Éster CarboxílicoRESUMO
The discovery of the spin Hall effect1 enabled the efficient generation and manipulation of the spin current. More recently, the magnetic spin Hall effect2,3 was observed in non-collinear antiferromagnets, where the spin conservation is broken due to the non-collinear spin configuration. This provides a unique opportunity to control the spin current and relevant device performance with controllable magnetization. Here, we report a magnetic spin Hall effect in a collinear antiferromagnet, Mn2Au. The spin currents are generated at two spin sublattices with broken spatial symmetry, and the antiparallel antiferromagnetic moments play an important role. Therefore, we term this effect the 'antiferromagnetic spin Hall effect'. The out-of-plane spins from the antiferromagnetic spin Hall effect are favourable for the efficient switching of perpendicular magnetized devices, which is required for high-density applications. The antiferromagnetic spin Hall effect adds another twist to the atomic-level control of spin currents via the antiferromagnetic spin structure.
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Drought stress adversely impacts crop development and yield. Maize frequently encounters drought stress during its life cycle. Improvement of drought tolerance is a priority of maize breeding programs. Here, we identified a novel transcription factor encoding gene, APETALA2 (AP2)/Ethylene response factor (ERF), which is tightly associated with drought tolerance in maize seedlings. ZmERF21 is mainly expressed in the root and leaf and it can be highly induced by polyethylene glycol treatment. Genetic analysis showed that the zmerf21 mutant plants displayed a reduced drought tolerance phenotype, accompanied by phenotypical and physiological changes that are commonly observed in drought conditions. Overexpression of ZmERF21 in maize significantly increased the chlorophyll content and activities of antioxidant enzymes under drought conditions. RNA-Seq and DNA affinity purification sequencing analysis further revealed that ZmERF21 may directly regulate the expression of genes related to hormone (ethylene, abscisic acid) and Ca signaling as well as other stress-response genes through binding to the promoters of potential target genes. Our results thereby provided molecular evidence of ZmERF21 is involved in the drought stress response of maize.
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Secas , Expressão Gênica/fisiologia , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Transdução de Sinais/genética , Zea mays/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/metabolismo , Plântula/genética , Plântula/fisiologia , Estresse Fisiológico/genética , Zea mays/genéticaRESUMO
Dual-wavelength switchable emission has been demonstrated in InGaN quantum dot (QD) micro-cavity light-emitting diodes (MCLEDs). By simply modulating the injected current levels, the output of the device can be dynamically tuned between the two distinct cavity modes at 498.5 and 541.7 nm, exhibiting deterministic mode switching in the green spectral range. Owing to the microcavity effect, high spectral purity with a narrow linewidth of 0.21 nm was obtained. According to the experimental and theoretical results, it can be concluded that the dual-wavelength switching for the investigated MCLEDs is ascribed to the broad and tunable gain of a thin InGaN QD active region, together with the mode selection and enhancement effect of the cavity. To provide additional guidelines for controllable dual-wavelength switchable operation in nitride-based light-emitting devices, detailed design and fabrication strategies are discussed. This work presents an effective method to achieve mode switching for practical applications such as multi-wavelength optical recording, frequency mixing, flip-flop and optical switches.
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An efficient and practical strategy was developed to synthesize 1,3,4-triaryl-6-trifluoromethylpyridones from CF3-imidoyl sulfoxonium ylides and cyclopropenones in good to excellent yields. This stepwise [3 + 3] annulation reaction was carried out under transition-metal-, additive-, and solvent-free conditions, generating 1 equiv of dimethyl sulfoxide as byproduct and tolerating a series of functional groups.
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In this work, novel metal-organic framework/polyimide (MOF/PI) composite films possessing dielectric properties were synthesized via a solution blending method. UiO-66 and UiO-66-NH2 nanoparticles were first prepared by a hydrothermal method and added into PI to obtain the composite films. Compared with pure PI, the dielectric properties of the MOF/PI composites were substantially enhanced. The amine functionalization gave UiO-66-NH2/PI composite films better dielectric properties in comparison with UiO-66/PI composite films because of improved interaction between PI and UiO-66-NH2. It showed that the dielectric constant of the PI composite film containing 20 wt% UiO-66-NH2 is 8.8 at 102 Hz, which was approximately 2.5 times that of the pure PI (3.5 at 102 Hz). The dielectric loss of the composite film was less than 0.034. Moreover, the breakdown strength of 20 wt% UiO-66-NH2/PI composite films was found to be 208 kV/mm. We describe this new perspective for the preparation of high-performance polymer-based dielectric materials and their application as electrical materials.
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The unc-13 homolog B (UNC13B) gene encodes a presynaptic protein, mammalian uncoordinated 13-2 (Munc13-2), which is highly expressed in the brain-predominantly in the cerebral cortex-and plays an essential role in synaptic vesicle priming and fusion, potentially affecting neuronal excitability. However, the functional significance of the UNC13B mutation in human disease is not known. In this study, we screened for novel genetic variants in a cohort of 446 unrelated cases (families) with partial epilepsy without acquired causes by trio-based whole-exome sequencing. UNC13B variants were identified in 12 individuals affected by partial epilepsy and/or febrile seizures from eight unrelated families. The eight probands all had focal seizures and focal discharges in EEG recordings, including two patients who experienced frequent daily seizures and one who showed abnormalities in the hippocampus by brain MRI; however, all of the patients showed a favourable outcome without intellectual or developmental abnormalities. The identified UNC13B variants included one nonsense variant, two variants at or around a splice site, one compound heterozygous missense variant and four missense variants that cosegregated in the families. The frequency of UNC13B variants identified in the present study was significantly higher than that in a control cohort of Han Chinese and controls of the East Asian and all populations in the Genome Aggregation Database (gnomAD). Computational modelling, including hydrogen bond and docking analyses, suggested that the variants lead to functional impairment. In Drosophila, seizure rate and duration were increased by Unc13b knockdown compared to wild-type flies, but these effects were less pronounced than in sodium voltage-gated channel alpha subunit 1 (Scn1a) knockdown Drosophila. Electrophysiological recordings showed that excitatory neurons in Unc13b-deficient flies exhibited increased excitability. These results indicate that UNC13B is potentially associated with epilepsy. The frequent daily seizures and hippocampal abnormalities but ultimately favourable outcome under anti-epileptic therapy in our patients indicate that partial epilepsy caused by UNC13B variant is a clinically manageable condition.
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Epilepsias Parciais/diagnóstico por imagem , Epilepsias Parciais/genética , Variação Genética/genética , Proteínas do Tecido Nervoso/genética , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Criança , Pré-Escolar , Drosophila , Epilepsias Parciais/fisiopatologia , Feminino , Humanos , Masculino , Resultado do TratamentoRESUMO
Southern corn leaf blight (SCLB), caused by Bipolaris maydis, is one of the most devastating diseases affecting maize production. However, only one SLCB resistance gene, conferring partial resistance, is currently known, underscoring the importance of isolating new SCLB resistance-related genes. Here, we performed a comparative proteomic analysis and identified 258 proteins showing differential abundance during the maize response to B. maydis. These proteins included an ascorbate peroxidase (Zea mays ascorbate peroxidase 1 (ZmAPX1)) encoded by a gene located within the mapping interval of a previously identified quantitative trait locus associated with SCLB resistance. ZmAPX1 overexpression resulted in lower H2 O2 accumulation and enhanced resistance against B. maydis. Jasmonic acid (JA) contents and transcript levels for JA biosynthesis and responsive genes increased in ZmAPX1-overexpressing plants infected with B. maydis, whereas Zmapx1 mutants showed the opposite effects. We further determined that low levels of H2 O2 are accompanied by an accumulation of JA that enhances SCLB resistance. These results demonstrate that ZmAPX1 positively regulates SCLB resistance by decreasing H2 O2 accumulation and activating the JA-mediated defense signaling pathway. This study identified ZmAPX1 as a potentially useful gene for increasing SCLB resistance. Furthermore, the generated data may be relevant for clarifying the functions of plant APXs.
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Doenças das Plantas , Zea mays , Ascorbato Peroxidases/genética , Ascorbato Peroxidases/metabolismo , Resistência à Doença/genética , Doenças das Plantas/genética , Plantas , Proteômica , Zea mays/genética , Zea mays/metabolismoRESUMO
BACKGROUND: Appropriate flowering time is very important to the success of modern agriculture. Maize (Zea mays L.) is a major cereal crop, originated in tropical areas, with photoperiod sensitivity. Which is an important obstacle to the utilization of tropical/subtropical germplasm resources in temperate regions. However, the study on the regulation mechanism of photoperiod sensitivity of maize is still in the early stage. Although it has been previously reported that ZmCCT is involved in the photoperiod response and delays maize flowering time under long-day conditions, the underlying mechanism remains unclear. RESULTS: Here, we showed that ZmCCT overexpression delays flowering time and confers maize drought tolerance under LD conditions. Implementing the Gal4-LexA/UAS system identified that ZmCCT has a transcriptional inhibitory activity, while the yeast system showed that ZmCCT has a transcriptional activation activity. DAP-Seq analysis and EMSA indicated that ZmCCT mainly binds to promoters containing the novel motifs CAAAAATC and AAATGGTC. DAP-Seq and RNA-Seq analysis showed that ZmCCT could directly repress the expression of ZmPRR5 and ZmCOL9, and promote the expression of ZmRVE6 to delay flowering under long-day conditions. Moreover, we also demonstrated that ZmCCT directly binds to the promoters of ZmHY5, ZmMPK3, ZmVOZ1 and ZmARR16 and promotes the expression of ZmHY5 and ZmMPK3, but represses ZmVOZ1 and ZmARR16 to enhance stress resistance. Additionally, ZmCCT regulates a set of genes associated with plant development. CONCLUSIONS: ZmCCT has dual functions in regulating maize flowering time and stress response under LD conditions. ZmCCT negatively regulates flowering time and enhances maize drought tolerance under LD conditions. ZmCCT represses most flowering time genes to delay flowering while promotes most stress response genes to enhance stress tolerance. Our data contribute to a comprehensive understanding of the regulatory mechanism of ZmCCT in controlling maize flowering time and stress response.