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1.
J Integr Plant Biol ; 66(2): 172-175, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38314481

RESUMO

Carotenoid isomerase activity and carotenoid content maintain the appropriate tiller number, photosynthesis, and grain yield. Interactions between the strigolactone and abscisic acid pathways regulates tiller formation.


Assuntos
Oryza , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Carotenoides/metabolismo , Grão Comestível/metabolismo , Isomerases/metabolismo
2.
Drug Saf ; 47(2): 173-182, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38062261

RESUMO

INTRODUCTION: The Vaccine Adverse Event Reporting System (VAERS) has already been challenged by an extreme increase in the number of individual case safety reports (ICSRs) after the market introduction of coronavirus disease 2019 (COVID-19) vaccines. Evidence from scientific literature suggests that when there is an extreme increase in the number of ICSRs recorded in spontaneous reporting databases (such as the VAERS), an accompanying increase in the number of disproportionality signals (sometimes referred to as 'statistical alerts') generated is expected. OBJECTIVES: The objective of this study was to develop a natural language processing (NLP)-based approach to optimize signal management by excluding disproportionality signals related to listed adverse events following immunization (AEFIs). COVID-19 vaccines were used as a proof-of-concept. METHODS: The VAERS was used as a data source, and the Finding Associated Concepts with Text Analysis (FACTA+) was used to extract signs and symptoms of listed AEFIs from MEDLINE for COVID-19 vaccines. Disproportionality analyses were conducted according to guidelines and recommendations provided by the US Centers for Disease Control and Prevention. By using signs and symptoms of listed AEFIs, we computed the proportion of disproportionality signals dismissed for COVID-19 vaccines using this approach. Nine NLP techniques, including Generative Pre-Trained Transformer 3.5 (GPT-3.5), were used to automatically retrieve Medical Dictionary for Regulatory Activities Preferred Terms (MedDRA PTs) from signs and symptoms extracted from FACTA+. RESULTS: Overall, 17% of disproportionality signals for COVID-19 vaccines were dismissed as they reported signs and symptoms of listed AEFIs. Eight of nine NLP techniques used to automatically retrieve MedDRA PTs from signs and symptoms extracted from FACTA+ showed suboptimal performance. GPT-3.5 achieved an accuracy of 78% in correctly assigning MedDRA PTs. CONCLUSION: Our approach reduced the need for manual exclusion of disproportionality signals related to listed AEFIs and may lead to better optimization of time and resources in signal management.


Assuntos
Sistemas de Notificação de Reações Adversas a Medicamentos , Processamento de Linguagem Natural , Vacinas , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Vacinas/efeitos adversos
3.
Plant Commun ; 5(1): 100673, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-37596786

RESUMO

Grain size is an important determinant of grain yield in rice. Although dozens of grain size genes have been reported, the molecular mechanisms that control grain size remain to be fully clarified. Here, we report the cloning and characterization of GR5 (GRAIN ROUND 5), which is allelic to SMOS1/SHB/RLA1/NGR5 and encodes an AP2 transcription factor. GR5 acts as a transcriptional activator and determines grain size by influencing cell proliferation and expansion. We demonstrated that GR5 physically interacts with five Gγ subunit proteins (RGG1, RGG2, DEP1, GS3, and GGC2) and acts downstream of the G protein complex. Four downstream target genes of GR5 in grain development (DEP2, DEP3, DRW1, and CyCD5;2) were revealed and their core T/CGCAC motif identified by yeast one-hybrid, EMSA, and ChIP-PCR experiments. Our results revealed that GR5 interacts with Gγ subunits and cooperatively determines grain size by regulating the expression of downstream target genes. These findings provide new insight into the genetic regulatory network of the G protein signaling pathway in the control of grain size and provide a potential target for high-yield rice breeding.


Assuntos
Oryza , Oryza/metabolismo , Redes Reguladoras de Genes , Grão Comestível/genética , Grão Comestível/metabolismo , Transdução de Sinais , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo
4.
Plant Biotechnol J ; 22(4): 915-928, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37983630

RESUMO

Grain weight is an important determinant of grain yield. However, the underlying regulatory mechanisms for grain size remain to be fully elucidated. Here, we identify a rice mutant grain weight 9 (gw9), which exhibits larger and heavier grains due to excessive cell proliferation and expansion in spikelet hull. GW9 encodes a nucleus-localized protein containing both C2H2 zinc finger (C2H2-ZnF) and VRN2-EMF2-FIS2-SUZ12 (VEFS) domains, serving as a negative regulator of grain size and weight. Interestingly, the non-frameshift mutations in C2H2-ZnF domain result in increased plant height and larger grain size, whereas frameshift mutations in both C2H2-ZnF and VEFS domains lead to dwarf and malformed spikelet. These observations indicated the dual functions of GW9 in regulating grain size and floral organ identity through the C2H2-ZnF and VEFS domains, respectively. Further investigation revealed the interaction between GW9 and the E3 ubiquitin ligase protein GW2, with GW9 being the target of ubiquitination by GW2. Genetic analyses suggest that GW9 and GW2 function in a coordinated pathway controlling grain size and weight. Our findings provide a novel insight into the functional role of GW9 in the regulation of grain size and weight, offering potential molecular strategies for improving rice yield.


Assuntos
Oryza , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Grão Comestível/genética , Grão Comestível/metabolismo , Ubiquitinação , Regulação da Expressão Gênica de Plantas/genética
5.
Rice (N Y) ; 16(1): 47, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37874376

RESUMO

Soil salinization is one of the most common abiotic stresses of rice, which seriously affects the normal growth of rice. Breeding salt-tolerant varieties have become one of the important ways to ensure food security and sustainable agricultural development. However, the mechanisms underlying salt tolerance control still need to be clarified. In this study, we identified a mutant, termed salt-tolerant and small grains(sts), with salt tolerance and small grains. Gene cloning and physiological and biochemical experiments reveal that sts is a novel mutant allele of Mitogen-activated protein Kinase Kinase 4 (OsMKK4), which controls the grain size, and has recently been found to be related to salt tolerance in rice. Functional analysis showed that OsSTS is constitutively expressed throughout the tissue, and its proteins are localized to the nucleus, cell membrane, and cytoplasm. It was found that the loss of OsSTS function enhanced the salt tolerance of rice seedlings, and further studies showed that the loss of OsSTS function increased the ROS clearance rate of rice seedlings, independent of ionic toxicity. In order to explore the salt tolerance mechanism of sts, we found that the salt tolerance of sts is also regulated by ABA through high-throughput mRNA sequencing. Salt and ABA treatment showed that ABA might alleviate the inhibitory effect of salt stress on root length in sts. These results revealed new functions of grain size gene OsMKK4, expanded new research ideas related to salt tolerance mechanism and hormone regulation network, and provided a theoretical basis for salt-tolerant rice breeding.

6.
BMC Plant Biol ; 23(1): 418, 2023 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-37689677

RESUMO

BACKGROUND: Mitochondrion is the key respiratory organ and participate in multiple anabolism and catabolism pathways in eukaryote. However, the underlying mechanism of how mitochondrial membrane proteins regulate leaf and grain development remains to be further elucidated. RESULTS: Here, a mitochondria-defective mutant narrow leaf and slender grain 1 (nlg1) was identified from an EMS-treated mutant population, which exhibits narrow leaves and slender grains. Moreover, nlg1 also presents abnormal mitochondria structure and was sensitive to the inhibitors of mitochondrial electron transport chain. Map-based cloning and transgenic functional confirmation revealed that NLG1 encodes a mitochondrial import inner membrane translocase containing a subunit Tim21. GUS staining assay and RT-qPCR suggested that NLG1 was mainly expressed in leaves and panicles. The expression level of respiratory function and auxin response related genes were significantly down-regulated in nlg1, which may be responsible for the declination of ATP production and auxin content. CONCLUSIONS: These results suggested that NLG1 plays an important role in the regulation of leaf and grain size development by maintaining mitochondrial homeostasis. Our finding provides a novel insight into the effects of mitochondria development on leaf and grain morphogenesis in rice.


Assuntos
Oryza , Oryza/genética , Membranas Mitocondriais , Folhas de Planta/genética , Mitocôndrias , Grão Comestível/genética , Ácidos Indolacéticos , Proteínas de Membrana/genética
7.
Dev Cell ; 58(16): 1489-1501.e5, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37413992

RESUMO

How reciprocal regulation of carbon and nitrogen metabolism works is a long-standing question. In plants, glucose and nitrate are proposed to act as signaling molecules, regulating carbon and nitrogen metabolism via largely unknown mechanisms. Here, we show that the MYB-related transcription factor ARE4 coordinates glucose signaling and nitrogen utilization in rice. ARE4 is retained in the cytosol in complexing with the glucose sensor OsHXK7. Upon sensing a glucose signal, ARE4 is released, is translocated into the nucleus, and activates the expression of a subset of high-affinity nitrate transporter genes, thereby boosting nitrate uptake and accumulation. This regulatory scheme displays a diurnal pattern in response to circadian changes of soluble sugars. The are4 mutations compromise in nitrate utilization and plant growth, whereas overexpression of ARE4 increases grain size. We propose that the OsHXK7-ARE4 complex links glucose to the transcriptional regulation of nitrogen utilization, thereby coordinating carbon and nitrogen metabolism.


Assuntos
Glucose , Oryza , Glucose/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Oryza/metabolismo , Nitratos/metabolismo , Nitrogênio/metabolismo , Regulação da Expressão Gênica de Plantas
8.
Expert Opin Drug Saf ; 22(1): 59-70, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36737057

RESUMO

OBJECTIVES: This study aimed at providing pooled estimates of the incidence of adverse drug reactions (ADRs) of ubrogepant and rimegepant and to use meta-regression to identify correlations between the occurrence of selected ADRs, socio-demographic, and clinical characteristics from data published in clinical studies. METHODS: Ovid MEDLINE (up to 03/02/2022) was searched along with the references listed in the reviews identified with the research query. Random intercept and slope logistic regression models were used to estimate the logit transformation of the pooled incidence. To examine how selected clinical and socio-demographic characteristics correlated with the pooled incidence rates, we performed random-effects meta-regression. RESULTS: Significant heterogeneity of incidence estimates was observed in clinical studies along with correlations between ADRs and the sociodemographic and clinical characteristics of patients exposed to ubrogepant. In particular, we observed a correlation between ubrogepant dosage and muscle strain and between Body Mass Index (BMI) and liver function values. For rimegepant, significant correlations were observed between age and infections and having aura symptoms at baseline and nausea/dizziness/diarrhea/muscle strain. CONCLUSION: This study provided pooled incidence estimates of ubrogepant and rimegepant's ADRs and highlighted new safety aspects of the pharmacological treatment with ubrogepants and rimigepants from correlations obtained from the meta-regression.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Piridinas , Humanos , Piridinas/efeitos adversos , Piperidinas , Pirróis/efeitos adversos
9.
Plant Biotechnol J ; 21(4): 819-838, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36597711

RESUMO

Plant architecture and stress tolerance play important roles in rice breeding. Specific leaf morphologies and ideal plant architecture can effectively improve both abiotic stress resistance and rice grain yield. However, the mechanism by which plants simultaneously regulate leaf morphogenesis and stress resistance remains elusive. Here, we report that SRL10, which encodes a double-stranded RNA-binding protein, regulates leaf morphology and thermotolerance in rice through alteration of microRNA biogenesis. The srl10 mutant had a semi-rolled leaf phenotype and elevated sensitivity to high temperature. SRL10 directly interacted with catalase isozyme B (CATB), and the two proteins mutually increased one other's stability to enhance hydrogen peroxide (H2 O2 ) scavenging, thereby contributing to thermotolerance. The natural Hap3 (AGC) type of SRL10 allele was found to be present in the majority of aus rice accessions, and was identified as a thermotolerant allele under high temperature stress in both the field and the growth chamber. Moreover, the seed-setting rate was 3.19 times higher and grain yield per plant was 1.68 times higher in near-isogenic line (NIL) carrying Hap3 allele compared to plants carrying Hap1 allele under heat stress. Collectively, these results reveal a new locus of interest and define a novel SRL10-CATB based regulatory mechanism for developing cultivars with high temperature tolerance and stable yield. Furthermore, our findings provide a theoretical basis for simultaneous breeding for plant architecture and stress resistance.


Assuntos
Oryza , Termotolerância , Termotolerância/genética , Oryza/metabolismo , Catalase/genética , Catalase/metabolismo , Isoenzimas/metabolismo , Melhoramento Vegetal , Grão Comestível , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo
10.
Plant Physiol ; 191(1): 280-298, 2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-36102807

RESUMO

Plant height and tiller number are two major factors determining plant architecture and yield. However, in rice (Oryza sativa), the regulatory mechanism of plant architecture remains to be elucidated. Here, we reported a recessive rice mutant presenting dwarf and reduced tillering phenotypes (drt1). Map-based cloning revealed that the phenotypes are caused by a single point mutation in DRT1, which encodes the Class I formin protein O. sativa formin homolog 13 (OsFH13), binds with F-actin, and promotes actin polymerization for microfilament organization. DRT1 protein localized on the plasma membrane (PM) and chloroplast (CP) outer envelope. DRT1 interacted with rice phototropin 2 (OsPHOT2), and the interaction was interrupted in drt1. Upon blue light stimulus, PM localized DRT1 and OsPHOT2 were translocated onto the CP membrane. Moreover, deficiency of DRT1 reduced OsPHOT2 internalization and OsPHOT2-mediated CP relocation. Our study suggests that rice formin protein DRT1/OsFH13 is necessary for plant morphology and CP relocation by modulating the actin-associated cytoskeleton network.


Assuntos
Actinas , Oryza , Actinas/metabolismo , Oryza/metabolismo , Forminas/genética , Forminas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Cloroplastos/metabolismo , Mutação/genética , Regulação da Expressão Gênica de Plantas
11.
Front Pharmacol ; 14: 1279516, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38375209

RESUMO

Introduction: Human basic fibroblast growth factor (hbFGF) is a highly valuable multifunctional protein that plays a crucial role in various biological processes. In this study, we aim to accomplish the scaling-up production of mature hbFGF (146aa) by implementing a high cell-density fermentation and purification process on a 500-L scale, thereby satisfying the escalating demands for both experimental research and clinical applications. Methods: The hbFGF DNA fragment was cloned into a mpET-3c vector containing a kanamycin resistance gene and then inserted into Escherichia coli BL21 (DE3) plysS strain. To optimize the yield of hbFGF protein, various fermentation parameters were systematically optimized using BOX-Behnken design and further validated in large-scale fermentation (500-L). Additionally, a three-step purification protocol involving CM-Sepharose, heparin affinity, and SP-Sepharose column chromatography was developed to separate and purify the hbFGF protein. Isoelectric focusing electrophoresis, MALDI-TOF/MS analysis, amino acid sequencing, CD spectroscopy, and Western blotting were performed to authenticate its identity. The biological efficacy of purified hbFGF was evaluated using an MTT assay as well as in a diabetic deep second-degree scald model. Results: The engineered strain was successfully constructed, exhibiting high expression of hbFGF and excellent stability. Under the optimized fermentation conditions, an impressive bacterial yield of 46.8 ± 0.3 g/L culture with an expression level of hbFGF reaching 28.2% ± 0.2% was achieved in 500-L scale fermentation. Subsequently, during pilot-scale purification, the final yield of purified hbFGF protein was 114.6 ± 5.9 mg/L culture with RP-HPLC, SEC-HPLC, and SDS-PAGE purity exceeding 98%. The properties of purified hbFGF including its molecular weight, isoelectric point (pI), amino sequence, and secondary structure were found to be consistent with theoretical values. Furthermore, the purified hbFGF exhibited potent mitogenic activity with a specific value of 1.05 ± 0.94 × 106 AU/mg and significantly enhanced wound healing in a deep second-degree scald wound diabetic rat model. Conclusion: This study successfully established a stable and efficient large-scale production process of hbFGF, providing a solid foundation for future industrial production.

12.
Front Plant Sci ; 13: 1005203, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36388599

RESUMO

Highly seed vigor (SV) is essential for rice direct seeding (DS). Understanding the genetic mechanism of SV-related traits could contribute to increasing the efficiency of DS. However, only a few genes responsible for SV have been determined in rice, and the regulatory network of SV remains obscure. In this study, the seed germination rate (GR), seedling shoot length (SL), and shoot fresh weight (FW) related to SV traits were measured, and a genome-wide association study (GWAS) was conducted to detect high-quality loci responsible for SV using a panel of 346 diverse accessions. A total of 51 significant SNPs were identified and arranged into six quantitative trait locus (QTL) regions, including one (qGR1-1), two (qSL1-1, qSL1-2), and three (qFW1-1, qFW4-1, and qFW7-1) QTLs associated with GR, SL, and FW respectively, which were further validated using chromosome segment substitution lines (CSSLs). Integrating gene expression, gene annotation, and haplotype analysis, we found 21 strong candidate genes significantly associated with SV. In addition, the SV-related functions of LOC_Os01g11270 and LOC_Os01g55240 were further verified by corresponding CRISPR/Cas9 gene-edited mutants. Thus, these results provide clues for elucidating the genetic basis of SV control. The candidate genes or QTLs would be helpful for improving DS by molecular marker-assisted selection (MAS) breeding in rice.

13.
Int J Mol Sci ; 23(21)2022 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-36362403

RESUMO

Grain number per panicle (GNPP), determined mainly by panicle branching, is vital for rice yield. The dissection of the genetic basis underlying GNPP could help to improve rice yield. However, genetic resources, including quantitative trait loci (QTL) or genes for breeders to enhance rice GNPP, are still limited. Here, we conducted the genome-wide association study (GWAS) on the GNPP, primary branch number (PBN), and secondary branch number (SBN) of 468 rice accessions. We detected a total of 18 QTLs, including six for GNPP, six for PBN, and six for SBN, in the whole panel and the indica and japonica subpanels of 468 accessions. More importantly, qPSG1 was a common QTL for GNPP, PBN, and SBN and was demonstrated by chromosome segment substitution lines (CSSLs). Considering gene annotation, expression, and haplotype analysis, seven novel and strong GNPP-related candidate genes were mined from qPSG1. Our results provide clues to elucidate the molecular regulatory network of GNPP. The identified QTLs and candidate genes will contribute to the improvement of GNPP and rice yield via molecular marker-assisted selection (MAS) breeding and genetic engineering techniques.


Assuntos
Oryza , Locos de Características Quantitativas , Oryza/genética , Estudo de Associação Genômica Ampla , Fenótipo , Grão Comestível/genética
14.
Int J Mol Sci ; 23(19)2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36233316

RESUMO

APETALA2/ethylene response factor (AP2/ERF) is widely found in the plant kingdom and plays crucial roles in transcriptional regulation and defense response of plant growth and development. Based on the research progress related to AP2/ERF genes, this paper focuses on the classification and structural features of AP2/ERF transcription factors, reviews the roles of rice AP2/ERF genes in the regulation of growth, development and stress responses, and discusses rice breeding potential and challenges. Taken together; studies of rice AP2/ERF genes may help to elucidate and enrich the multiple molecular mechanisms of how AP2/ERF genes regulate spikelet determinacy and floral organ development, flowering time, grain size and quality, embryogenesis, root development, hormone balance, nutrient use efficiency, and biotic and abiotic response processes. This will contribute to breeding excellent rice varieties with high yield and high resistance in a green, organic manner.


Assuntos
Oryza , Fatores de Transcrição , Etilenos , Regulação da Expressão Gênica de Plantas , Hormônios , Família Multigênica , Oryza/genética , Oryza/metabolismo , Filogenia , Melhoramento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
Int J Mol Sci ; 23(15)2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35955949

RESUMO

Leaf morphology is one of the important traits related to ideal plant architecture and is an important factor determining rice stress resistance, which directly affects yield. Wax layers form a barrier to protect plants from different environmental stresses. However, the regulatory effect of wax synthesis genes on leaf morphology and salt tolerance is not well-understood. In this study, we identified a rice mutant, leaf tip rumpled 1 (ltr1), in a mutant library of the classic japonica variety Nipponbare. Phenotypic investigation of NPB and ltr1 suggested that ltr1 showed rumpled leaf with uneven distribution of bulliform cells and sclerenchyma cells, and disordered vascular bundles. A decrease in seed-setting rate in ltr1 led to decreased per-plant grain yield. Moreover, ltr1 was sensitive to salt stress, and LTR1 was strongly induced by salt stress. Map-based cloning of LTR1 showed that there was a 2-bp deletion in the eighth exon of LOC_Os02g40784 in ltr1, resulting in a frameshift mutation and early termination of transcription. Subsequently, the candidate gene was confirmed using complementation, overexpression, and knockout analysis of LOC_Os02g40784. Functional analysis of LTR1 showed that it was a wax synthesis gene and constitutively expressed in entire tissues with higher relative expression level in leaves and panicles. Moreover, overexpression of LTR1 enhanced yield in rice and LTR1 positively regulates salt stress by affecting water and ion homeostasis. These results lay a theoretical foundation for exploring the molecular mechanism of leaf morphogenesis and stress response, providing a new potential strategy for stress-tolerance breeding.


Assuntos
Oryza , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Oryza/metabolismo , Melhoramento Vegetal , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Tolerância ao Sal/genética
16.
Angew Chem Int Ed Engl ; 61(30): e202204271, 2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35545533

RESUMO

Herein, we demonstrate that the surface anchoring of black phosphorus quantum dots (BPQDs) and bulk iron-doping in W18 O49 nanowires significantly promotes the photocatalytic activity toward N2 fixation into NH3 . More specifically, a NH3 production rate of up to 187.6 µmol g-1 h-1 could be achieved, nearly one order of magnitude higher than that of pristine W18 O49 (18.9 µmol g-1 h-1 ). Comprehensive experiments and density-functional theory calculations reveal that Fe-doping could enhance the reducing ability of photo-generated electrons by decreasing the work function and elevating the defect band (d-band) centers. Additionally, the surface BPQDs anchoring could facilitate the N2 adsorption/activation owing to the increased adsorption energy and advantaged W-P dimer bonding-mode. Therefore, synergizing the surface BPQD anchoring and bulk Fe-doping remarkably enhanced the photocatalytic activity of W18 O49 nanowires for NH3 production.

17.
Theor Appl Genet ; 135(5): 1751-1766, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35258682

RESUMO

Phytohormones performed critical roles in regulating plant architecture and thus determine grain yield in rice. However, the roles of brassinosteroids (BRs) compared to other phytohormones in shaping rice architecture are less studied. In this study, we report that BR hypersensitive1 (BHS1) plays a negative role in BR signaling and regulate rice architecture. BHS1 encodes the kinesin-13a protein and regulates grain length. We found that bhs1 was hypersensitive to BR, while BHS1-overexpression was less sensitive to BR compare to WT. BHS1 was down-regulated at RNA and protein level upon exogenous BR treatment, and proteasome inhibitor MG132 delayed the BHS1 degradation, indicating that both the transcriptional and posttranscriptional regulation machineries are involved in BHS1-mediated regulation of plant growth and development. Furthermore, we found that the BR-induced degradation of BHS1 was attenuated in Osbri1 and Osbak1 mutants, but not in Osbzr1 and Oslic mutants. Together, these results suggest that BHS1 is a novel component which is involved in negative regulation of the BR signaling downstream player of BRI1.


Assuntos
Brassinosteroides , Oryza , Brassinosteroides/farmacologia , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas , Crescimento e Desenvolvimento , Cinesinas/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
18.
J Genet Genomics ; 49(5): 469-480, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35189402

RESUMO

Nitrogen is an essential macronutrient for all living organisms and is critical for crop productivity and quality. In higher plants, inorganic nitrogen is absorbed through roots and then assimilated into amino acids by the highly conserved glutamine synthetase/glutamine:2-oxoglutarate aminotransferase (GS/GOGAT) cycle. How nitrogen metabolism and nitrogen starvation responses of plants are regulated remains largely unknown. Previous studies revealed that mutations in the rice ABNORMAL CYTOKININ RESPONSE1 (ABC1) gene encoding Fd-GOGAT cause a typical nitrogen deficiency syndrome. Here, we show that ARE2 (for ABC1 REPRESSOR2) is a key regulator of nitrogen starvation responses in rice. The are2 mutations partially rescue the nitrogen-deficient phenotype of abc1 and the are2 mutants show enhanced tolerance to nitrogen deficiency, suggesting that ARE2 genetically interacts with ABC1/Fd-GOGAT. ARE2 encodes a chloroplast-localized RelA/SpoT homolog protein that catalyzes the hydrolysis of guanosine pentaphosphate or tetraphosphate (p)ppGpp, an alarmone regulating the stringent response in bacteria under nutritional stress conditions. The are2 mutants accumulate excessive amounts of (p)ppGpp, which correlate with lower levels of photosynthetic proteins and higher amino acid levels. Collectively, these observations suggest that the alarmone (p)ppGpp mediates nitrogen stress responses and may constitute a highly conserved mechanism from bacteria to plants.


Assuntos
Guanosina Pentafosfato , Oryza , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cloroplastos/metabolismo , Regulação Bacteriana da Expressão Gênica , Guanosina Pentafosfato/metabolismo , Guanosina Tetrafosfato/genética , Guanosina Tetrafosfato/metabolismo , Nitrogênio/metabolismo , Oryza/genética , Oryza/metabolismo , Plantas/metabolismo
19.
New Phytol ; 233(1): 344-359, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34610140

RESUMO

High-temperature stress inhibits normal cellular processes and results in abnormal growth and development in plants. However, the mechanisms by which rice (Oryza sativa) copes with high temperature are not yet fully understood. In this study, we identified a rice high temperature enhanced lesion spots 1 (hes1) mutant, which displayed larger and more dense necrotic spots under high temperature conditions. HES1 encoded a UDP-N-acetylglucosamine pyrophosphorylase, which had UGPase enzymatic activity. RNA sequencing analysis showed that photosystem-related genes were differentially expressed in the hes1 mutant at different temperatures, indicating that HES1 plays essential roles in maintaining chloroplast function. HES1 expression was induced under high temperature conditions. Furthermore, loss-of-function of HES1 affected heat shock factor expression and its mutation exhibited greater vulnerability to high temperature. Several experiments revealed that higher accumulation of reactive oxygen species occurred in the hes1 mutant at high temperature. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and comet experiments indicated that the hes1 underwent more severe DNA damage at high temperature. The determination of chlorophyll content and chloroplast ultrastructure showed that more severe photosystem defects occurred in the hes1 mutant under high temperature conditions. This study reveals that HES1 plays a key role in adaptation to high-temperature stress in rice.


Assuntos
Oryza , Regulação da Expressão Gênica de Plantas , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Temperatura
20.
Nat Commun ; 12(1): 6969, 2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34845221

RESUMO

Developing low-cost and highly efficient catalysts toward the efficient oxygen evolution reaction (OER) is highly desirable for photoelectrochemical (PEC) water splitting. Herein, we demonstrated that N-incorporation could efficiently activate NiFeOx catalysts for significantly enhancing the oxygen evolution activity and stability of BiVO4 photoanodes, and the photocurrent density has been achieved up to 6.4 mA cm-2 at 1.23 V (vs. reversible hydrogen electrode (RHE), AM 1.5 G). Systematic studies indicate that the partial substitution of O sites in NiFeOx catalysts by low electronegative N atoms enriched the electron densities in both Fe and Ni sites. The electron-enriched Ni sites conversely donated electrons to V sites of BiVO4 for restraining V5+ dissolution and improving the PEC stability, while the enhanced hole-attracting ability of Fe sites significantly promotes the oxygen-evolution activity. This work provides a promising strategy for optimizing OER catalysts to construct highly efficient and stable PEC water splitting devices.

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