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1.
Open Biol ; 14(6): 230427, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38862020

RESUMO

Hypertrophic cardiomyopathy (HCM) is a monogenic cardiac disorder commonly induced by sarcomere gene mutations. However, the mechanism for HCM is not well defined. Here, we generated transgenic MYH7 R453C and MYH6 R453C piglets and found both developed typical cardiac hypertrophy. Unexpectedly, we found serious fibrosis and cardiomyocyte loss in the ventricular of MYH7 R453C, not MYH6 R453C piglets, similar to HCM patients. Then, RNA-seq analysis and western blotting identified the activation of ERK1/2 and PI3K-Akt pathways in MYH7 R453C. Moreover, we observed an increased expression of fetal genes and an excess of reactive oxygen species (ROS) in MYH7 R453C piglet models, which was produced by Nox4 and subsequently induced inflammatory response. Additionally, the phosphorylation levels of Smad2/3, ERK1/2 and NF-kB p65 proteins were elevated in cardiomyocytes with the MYH7 R453C mutation. Furthermore, epigallocatechin gallate, a natural bioactive compound, could be used as a drug to reduce cell death by adjusting significant downregulation of the protein expression of Bax and upregulated Bcl-2 levels in the H9C2 models with MYH7 R453C mutation. In conclusion, our study illustrated that TGF-ß/Smad2/3, ERK1/2 and Nox4/ROS pathways have synergistic effects on cardiac remodelling and inflammation in MYH7 R453C mutation.


Assuntos
Cadeias Pesadas de Miosina , NADPH Oxidase 4 , NF-kappa B , Espécies Reativas de Oxigênio , Transdução de Sinais , Fator de Crescimento Transformador beta , Animais , Cadeias Pesadas de Miosina/metabolismo , Cadeias Pesadas de Miosina/genética , Fator de Crescimento Transformador beta/metabolismo , NADPH Oxidase 4/metabolismo , NADPH Oxidase 4/genética , Espécies Reativas de Oxigênio/metabolismo , NF-kappa B/metabolismo , Suínos , Miócitos Cardíacos/metabolismo , Humanos , Miosinas Cardíacas/metabolismo , Miosinas Cardíacas/genética , Modelos Animais de Doenças , Sistema de Sinalização das MAP Quinases , Animais Geneticamente Modificados , Proteína Smad2/metabolismo , Proteína Smad2/genética , Mutação , Proteína Smad3/metabolismo , Proteína Smad3/genética , Remodelação Ventricular , Cardiomiopatia Hipertrófica/metabolismo , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/patologia , Ratos
2.
Arterioscler Thromb Vasc Biol ; 43(1): e11-e28, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36412196

RESUMO

BACKGROUND: Elevated plasma Lp-PLA2 (lipoprotein-associated phospholipase A2) activity is closely associated with an increased risk of cardiovascular events. However, whether and how Lp-PLA2 is directly involved in the pathogenesis of atherosclerosis is still unclear. To examine the hypothesis that Lp-PLA2 could be a potential preventative target of atherosclerosis, we generated Lp-PLA2 knockout rabbits and investigated the pathophysiological functions of Lp-PLA2. METHODS: Lp-PLA2 knockout rabbits were generated using CRISPR/Cas9 system to assess the role of Lp-PLA2 in plasma lipids regulation and identify its underlying molecular mechanisms. Homozygous knockout rabbits along with wild-type rabbits were fed a cholesterol-rich diet for up to 14 weeks and their atherosclerotic lesions were compared. Moreover, the effects of Lp-PLA2 deficiency on the key cellular behaviors in atherosclerosis were assessed in vitro. RESULTS: When rabbits were fed a standard diet, Lp-PLA2 deficiency led to a significant reduction in plasma lipids. The decreased protein levels of SREBP2 (sterol regulatory element-binding protein 2) and HMGCR (3-hydroxy-3-methylglutaryl coenzyme A reductase) in livers of homozygous knockout rabbits indicated that the cholesterol biosynthetic pathway was impaired with Lp-PLA2 deficiency. In vitro experiments further demonstrated that intracellular Lp-PLA2 efficiently enhanced SREBP2-related cholesterol biosynthesis signaling independently of INSIGs (insulin-induced genes). When fed a cholesterol-rich diet, homozygous knockout rabbits exhibited consistently lower level of hypercholesterolemia, and their aortic atherosclerosis lesions were significantly reduced by 60.2% compared with those of wild-type rabbits. The lesions of homozygous knockout rabbits were characterized by reduced macrophages and the expression of inflammatory cytokines. Macrophages of homozygous knockout rabbits were insensitive to M1 polarization and showed reduced DiI-labeled lipoprotein uptake capacity compared with wild-type macrophages. Lp-PLA2 deficiency also inhibited the adhesion between monocytes and endothelial cells. CONCLUSIONS: These results demonstrate that Lp-PLA2 plays a causal role in regulating blood lipid homeostasis and Lp-PLA2 deficiency protects against dietary cholesterol-induced atherosclerosis in rabbits. Lp-PLA2 could be a potential target for the prevention of atherosclerosis.


Assuntos
Aterosclerose , Hiperlipidemias , Animais , Coelhos , 1-Alquil-2-acetilglicerofosfocolina Esterase/genética , Lipoproteína(a) , Fosfolipases , Células Endoteliais/metabolismo , Aterosclerose/genética , Aterosclerose/prevenção & controle , Lipídeos , Colesterol
3.
Nat Commun ; 13(1): 6960, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36379956

RESUMO

Germline determination is essential for species survival and evolution in multicellular organisms. In most flowering plants, formation of the female germline is initiated with specification of one megaspore mother cell (MMC) in each ovule; however, the molecular mechanism underlying this key event remains unclear. Here we report that spatially restricted auxin signaling promotes MMC fate in Arabidopsis. Our results show that the microRNA160 (miR160) targeted gene ARF17 (AUXIN RESPONSE FACTOR17) is required for promoting MMC specification by genetically interacting with the SPL/NZZ (SPOROCYTELESS/NOZZLE) gene. Alterations of auxin signaling cause formation of supernumerary MMCs in an ARF17- and SPL/NZZ-dependent manner. Furthermore, miR160 and ARF17 are indispensable for attaining a normal auxin maximum at the ovule apex via modulating the expression domain of PIN1 (PIN-FORMED1) auxin transporter. Our findings elucidate the mechanism by which auxin signaling promotes the acquisition of female germline cell fate in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , MicroRNAs , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Células Germinativas/metabolismo , Fatores de Transcrição/metabolismo
4.
Chin Med ; 17(1): 61, 2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35643582

RESUMO

Traditional Chinese medicine (TCM) has a long history, rich clinical experience, and unique advantages in the prevention and treatment of diseases. The quality and safety of Chinese medicinal materials (CMMs) directly affect the clinical efficacy and development of the TCM industry. However, confused provenance, counterfeiting and adulteration of CMMs hinder the acceptance of its therapeutic benefits in modern society. Therefore, the establishment and improvement of a TCM traceability system would be conducive to the transparency of the CMMs production, distribution, and circulation, thereby improving drug safety and promoting industry development. This review discusses the challenges faced in the development of TCM traceability system, the technologies currently available for tracing CMMs, and the potential application of Barcoded Microbial Spores (BMS) to improve CMMs origin traceability and TCM traceability systems.

5.
Front Plant Sci ; 13: 826473, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35222484

RESUMO

In flowering plants, male reproductive development is highly susceptible to heat stress. In this mini-review, we summarized different anomalies in tapetum, microspores, and pollen grains during anther development under heat stress. We then discussed how epigenetic control, particularly DNA methylation, is employed to cope with heat stress in male reproduction. Further understanding of epigenetic mechanisms by which plants manage heat stress during male reproduction will provide new genetic engineering and molecular breeding tools for generating heat-resistant crops.

6.
Front Plant Sci ; 11: 171, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32210987

RESUMO

FES1A is a heat shock protein 70 binding protein. Mutation of FES1A leads to a defect in thermotolerance of Arabidopsis; however, independent fes1a mutants exhibit a range in the extent of thermosensitivity. Here, we found that BRF2, a gene adjacent to FES1A and encoding a component of transcription factor IIIB, affects the thermosensitivity of fes1a mutants. Knockout of BRF2 suppressed fes1a thermosensitivity, while overexpression of BRF2 increased thermosensitivity of fes1a. BRF2 in fes1a mutants regulates the transcriptional strength of RNA Polymerase II and accumulation of heat shock proteins and eventually affects the thermotolerance of fes1a. There is a cross-talking between RNA Pol III and Pol II. The cross-talking is initiated by BRF, magnified by the mutation of FES1A, and finally has an effect on thermotolerance.

7.
Plant Cell ; 32(1): 206-225, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31732703

RESUMO

Cys2His2-like fold group (C2H2)-type zinc finger proteins promote root hair growth and development by regulating their target genes. However, little is known about their potential negative roles in root hair initiation and elongation. Here, we show that the C2H2-type zinc finger protein named ZINC FINGER PROTEIN1 (AtZP1), which contains an ERF-associated amphiphilic repression (EAR) motif, negatively regulates Arabidopsis (Arabidopsis thaliana) root hair initiation and elongation. Our results demonstrate that AtZP1 is highly expressed in root hairs and that AtZP1 inhibits transcriptional activity during root hair development. Plants overexpressing AtZP1 lacked root hairs, while loss-of-function mutants had longer and more numerous root hairs than the wild type. Transcriptome analysis indicated that AtZP1 downregulates genes encoding basic helix-loop-helix (bHLH) transcription factors associated with root hair cell differentiation and elongation. Mutation or deletion of the EAR motif substantially reduced the inhibitory activity of AtZP1. Chromatin immunoprecipitation assays, AtZP1:glucocorticoid receptor (GR) induction experiments, electrophoretic mobility shift assays, and yeast one-hybrid assays showed that AtZP1 directly targets the promoters of bHLH transcription factor genes, including the key root hair initiation gene ROOT HAIR DEFECTIVE6 (RHD6) and root hair elongation genes ROOT HAIR DEFECTIVE 6-LIKE 2 (RSL2) and RSL4, and suppresses root hair development. Our findings suggest that AtZP1 functions downstream of GL2 and negatively regulates root hair initiation and elongation, by suppressing RHD6, RSL4, and RSL2 transcription via the GL2/ZP1/RSL pathway.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Homeodomínio/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Dedos de Zinco/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Mutação , Organogênese Vegetal , Fenótipo , Raízes de Plantas/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Dedos de Zinco/genética
8.
Life Sci ; 227: 201-211, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31002917

RESUMO

AIMS: Colorectal cancer syndrome has been one of the greatest concerns in the world. Although several epidemiological studies have shown that hepatic low lipoprotein lipase (LPL) mRNA expression may be associated with dyslipidemia and tumor progression, it is still not known whether the liver plays an essential role in hyperlipidemia of ApcMin/+ mice. MAIN METHODS: We measured the expression of metabolic enzymes that involved fatty acid uptake, de novo lipogenesis (DNL), ß-oxidation and investigated hepatic triglyceride production in the liver of wild-type and ApcMin/+ mice. KEY FINDINGS: We found that hepatic fatty acid uptake and DNL decreased, but there was no significant difference in fatty acid ß-oxidation. Interestingly, the production of hepatic very low-density lipoprotein-triglyceride (VLDL-TG) decreased at 20 weeks of age, but marked steatosis was observed in the livers of the ApcMin/+ mouse. To further explore hypertriglyceridemia, we assessed the function of hepatic glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1) for the first time. GPIHBP1 is governed by the transcription factor octamer-binding transcription factor-1 (Oct-1) which are involved in the nuclear factor-κB (NF-κB) signaling pathway in the liver of ApcMin/+ mice. Importantly, it was also confirmed that sn50 (100 µg/mL, an inhibitor of the NF-κB) reversed the tumor necrosis factor α (TNFα)-induced Oct-1 and GPIHBP1 reduction in HepG2 cells. SIGNIFICANCE: Altogether, these findings highlighted a novel role of GPIHBP1 that might be responsible for hypertriglyceridemia in ApcMin/+ mice. Hypertriglyceridemia in these mice may be associated with their hepatic lipid metabolism development.


Assuntos
Fígado/metabolismo , Receptores de Lipoproteínas/fisiologia , Triglicerídeos/metabolismo , Animais , Caquexia/metabolismo , Caquexia/fisiopatologia , Neoplasias do Colo/fisiopatologia , Ácidos Graxos/metabolismo , Fígado Gorduroso/patologia , Regulação da Expressão Gênica/genética , Células Hep G2 , Humanos , Hiperlipidemias/genética , Metabolismo dos Lipídeos/genética , Lipídeos/fisiologia , Lipogênese/fisiologia , Lipólise/fisiologia , Lipoproteínas VLDL/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 1 de Transcrição de Octâmero/fisiologia , Receptores de Lipoproteínas/genética , Receptores de Lipoproteínas/metabolismo , Triglicerídeos/genética , Fator de Necrose Tumoral alfa/fisiologia
9.
J Infect Public Health ; 12(6): 789-793, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31003836

RESUMO

BACKGROUND: Infection analysisamongst malignant cancer patients remains elusive. The objective of this study is to investigate the characteristics of both infection and anti-infection treatments in patients group with malignant cancer. METHODS: We retrospectively studied the clinical data of 148 patients with malignant cancer and 171 benign patients enrolled in the pharmacist consultation from April 2015 to April 2017. Statistical analysis was performed by chi-square test to compare the classification of primary disease, sites of infection, composition of pathogenic bacteria, and the effectiveness of drug treatment. P value <0.05 was considered statistically significant. RESULTS: A total of 102 pathogen strains were detected in the patients with malignant cancer and 129 pathogen strains were noted in the benign patient group, respectively. Statistics indicated that more abdominal infections were observed in malignant cancer patients rather than in non-cancer patients. Additionally, more pseudomonas aeruginosa infection was found in the malignant cancer patient group while more Klebsiella pneumonia infection was noted in the benign group. These findings were supported by statistical evidence. There were fewer extended-spectrum ß-lactamases (ESBL) that produced Escherichia coli, which was commonly found in a gastrointestinal cancer patient group compared to patients under other types of cancer; it accounted for 51.3% of all malignant cases involved in the current study. CONCLUSIONS: Patients with malignant cancer are more likely to suffer from an infection containing pathogenic bacteria in comparison to benign patients. There have been considerable differences in the composition of pathogenic bacteria and its resistance to drugs. Overall, evaluating pathogens plays an essential role in the anti-infection treatment of patients with malignant cancer.


Assuntos
Antibacterianos/uso terapêutico , Bactérias/classificação , Bactérias/isolamento & purificação , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/epidemiologia , Neoplasias/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Criança , Pré-Escolar , Farmacorresistência Bacteriana , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Farmacêuticos , Encaminhamento e Consulta , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
10.
J Cardiovasc Pharmacol ; 73(5): 334-342, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30855405

RESUMO

To investigate the therapeutic effects of cyclodextrin on the development of atherosclerosis in rabbits, we evaluated the effects of (2-hydroxypropyl)-ß-cyclodextrin (HPßCD) therapy on the organ coefficient, lipid profiles, inflammatory cytokines, and atherosclerotic plaques in rabbits fed a high-fat diet. Our results demonstrated that HPßCD therapy reduced plasma triglyceride levels and inflammatory cytokine levels but increased plasma high-density lipoprotein cholesterol levels. HPßCD therapy produced a significant decrease in the atherosclerotic lesion area and reduced macrophage and collagen content in the lesions. The expression levels of inflammatory genes in aortic plaques were significantly reduced by HPßCD treatment, but the expression of ATP-binding cassette (ABC) transporters A1 (ABCA1) and G1 (ABCG1) in aortic plaques and livers increased significantly. HPßCD therapy may produce additional antiatherosclerotic benefits likely via increasing high-density lipoprotein cholesterol levels.


Assuntos
2-Hidroxipropil-beta-Ciclodextrina/farmacologia , Anti-Inflamatórios/farmacologia , Aorta/efeitos dos fármacos , Doenças da Aorta/prevenção & controle , Aterosclerose/prevenção & controle , HDL-Colesterol/sangue , Citocinas/sangue , Mediadores da Inflamação/sangue , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Aorta/metabolismo , Aorta/patologia , Doenças da Aorta/sangue , Doenças da Aorta/patologia , Aterosclerose/sangue , Aterosclerose/patologia , Biomarcadores/sangue , Dieta Hiperlipídica , Modelos Animais de Doenças , Progressão da Doença , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Placa Aterosclerótica , Coelhos , Regulação para Cima
11.
Int J Clin Exp Pathol ; 12(3): 759-767, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31933883

RESUMO

Colorectal cancer syndrome has been one of the greatest concerns in the world, particularly in developed countries. Several epidemiological studies have shown that dyslipidemia may be associated with the progression of intestinal cachexia, but there is little research on the function of the small intestine, which is involved in blood lipid metabolism, in dyslipidemia. In the present study, we aimed to explore the function of intestinal cholesterol absorption in the ApcMin/+ mouse model using an intestinal lipid absorption test. We found that both triglyceride (TG) and total cholesterol (TC) uptake were inhibited in the intestine of ApcMin/+ mice with age and the intestinal peroxisome proliferator-activated receptor α (PPARα) downregulated the processes of ß-oxidation, oxidative stress response, and cholesterol absorption in APC-deficient mice. In addition, reduced expression levels of farnesoid X receptor (FXR) and apical sodium-dependent bile acid transporter (ASBT) indicated that bile acid metabolism might be associated with intestinal cholesterol absorption in ApcMin/+ mice. Thus, our data suggested that the intestine plays an essential role in cholesterol uptake and that bile acid metabolism seems to cause a decrease in intestinal cholesterol uptake in ApcMin/+ mice.

12.
J Integr Plant Biol ; 60(7): 591-607, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29575603

RESUMO

Hydrogen peroxide (H2 O2 ) is generated in many metabolic processes. As a signaling molecule, H2 O2 plays important roles in plant growth and development, as well as environmental stress response. In Arabidopsis, there are three catalase genes, CAT1, CAT2, and CAT3. The encoded catalases are predominately peroxisomal proteins and are critical for scavenging H2 O2 . Since CAT1 and CAT3 are linked on chromosome 1, it has been almost impossible to generate cat1/3 and cat1/2/3 mutants by traditional genetic tools. In this study, we constructed cat1/3 double mutants and cat1/2/3 triple mutants by CRISPR/Cas9 to investigate the role of catalases. The cat1/2/3 triple mutants displayed severe redox disturbance and growth defects under physiological conditions compared with wild-type and the cat2/3 double mutants. Transcriptome analysis showed a more profound transcriptional response in the cat1/2/3 triple mutants compared to the cat2/3 mutants. These differentially expressed genes are involved in plant growth regulation as well as abiotic and biotic stress responses. In addition, expression of OXI1 (OXIDATIVE SIGNAL INDUCIBLE 1) and several MAPK cascade genes were changed dramatically in the catalase triple mutant, suggesting that H2 O2 produced in peroxisomes could serve as a peroxisomal retrograde signal.


Assuntos
Arabidopsis/enzimologia , Arabidopsis/crescimento & desenvolvimento , Catalase/genética , Mutação/genética , Peroxissomos/metabolismo , Desenvolvimento Vegetal , Transdução de Sinais , Arabidopsis/genética , Arabidopsis/fisiologia , Sequência de Bases , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Oxirredução , Desenvolvimento Vegetal/genética , Reprodução , Estresse Fisiológico/genética , Transcriptoma/genética
13.
Plant Cell ; 29(6): 1335-1356, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28522549

RESUMO

Plants extensively employ leucine-rich repeat receptor-like kinases (LRR-RLKs), the largest family of RLKs, to control a wide range of growth and developmental processes as well as defense responses. To date, only a few direct downstream effectors for LRR-RLKs have been identified. We previously showed that the LRR-RLK EMS1 (EXCESS MICROSPOROCYTES1) and its ligand TPD1 (TAPETUM DETERMINANT1) are required for the differentiation of somatic tapetal cells and reproductive microsporocytes during early anther development in Arabidopsis thaliana Here, we report the identification of ß-carbonic anhydrases (ßCAs) as the direct downstream targets of EMS1. EMS1 biochemically interacts with ßCA proteins. Loss of function of ßCA genes caused defective tapetal cell differentiation, while overexpression of ßCA1 led to the formation of extra tapetal cells. EMS1 phosphorylates ßCA1 at four sites, resulting in increased ßCA1 activity. Furthermore, phosphorylation-blocking mutations impaired the function of ßCA1 in tapetal cell differentiation; however, a phosphorylation mimic mutation promoted the formation of tapetal cells. ßCAs are also involved in pH regulation in tapetal cells. Our findings highlight the role of ßCA in controlling cell differentiation and provide insights into the posttranslational modification of carbonic anhydrases via receptor-like kinase-mediated phosphorylation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/metabolismo , Proteínas Quinases/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Anidrases Carbônicas/genética , Anidrases Carbônicas/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Regulação da Expressão Gênica de Plantas , Mutação , Plantas Geneticamente Modificadas , Proteínas Quinases/genética
15.
PLoS One ; 12(1): e0165195, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28052078

RESUMO

Sorghum (Sorghum bicolor L. Moench) is one of the most important grain crops in the world. The nuclear male sterility (NMS) trait, which is caused by mutations on the nuclear gene, is valuable for hybrid breeding and genetic studies. Several NMS mutants have been reported previously, but none of them were well characterized. Here, we present our detailed morphological characterization of a new and easily recognizable NMS sorghum mutant male sterile 8 (ms8) isolated from an elite inbred BTx623 mutagenized by ethyl methane sulfonate (EMS). Our results show that the ms8 mutant phenotype was caused by a mutation on a single recessive nuclear gene that is different from all available NMS loci reported in sorghum. In fertile sorghum plants, yellow anthers appeared first during anthesis, while in the ms8 mutant, white hairy stigma emerged first and only small white anthers were observed, making ms8 plants easily recognizable when flowering. The ovary development and seed production after manual pollination are normal in the ms8 mutant, indicating it is female fertile and male sterile only. We found that ms8 anthers did not produce pollen grains. Further analysis revealed that ms8 anthers were defective in tapetum development, which led to the arrest of pollen formation. As a stable male sterile mutant across different environments, greenhouses, and fields in different locations, the ms8 mutant could be a useful breeding tool. Moreover, ms8 might be an important for elucidating male gametophyte development in sorghum and other plants.


Assuntos
Núcleo Celular/genética , Mutação/genética , Sorghum/anatomia & histologia , Sorghum/genética , Fertilidade/genética , Loci Gênicos , Infertilidade das Plantas , Pólen/crescimento & desenvolvimento
16.
Front Microbiol ; 8: 2556, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29354099

RESUMO

Rhizobium sp. IRBG74 not only nodulates Sesbania cannabina but also can enhance rice growth; however, the underlying molecular mechanisms are not clear. Here, we show that Rhizobium sp. IRBG74 colonizes the roots of Arabidopsis thaliana, which leads to inhibition in the growth of main root but enhancement in the formation of lateral roots. The promotion of lateral root formation by Rhizobium sp. IRBG74 in the fls2-1 mutant, which is insensitive to flagellin, is similar to the wild-type plant, while the auxin response deficient mutant tir1-1 is significantly less sensitive to Rhizobium sp. IRBG74 than the wild type in terms of the inhibition of main root elongation and the promotion of lateral root formation. Further transcriptome analysis of Arabidopsis roots inoculated with Rhizobium sp. IRBG74 revealed differential expression of 50 and 211 genes at 24 and 48 h, respectively, and a majority of these genes are involved in auxin signaling. Consistent with the transcriptome analysis results, Rhizobium sp. IRBG74 treatment induces expression of the auxin responsive reporter DR5:GUS in roots. Our results suggest that in Arabidopsis Rhizobium sp. IRBG74 colonizes roots and promotes the lateral root formation likely through modulating auxin signaling. Our work provides insight into the molecular mechanisms of interactions between legume-nodulating rhizobia and non-legume plants.

17.
Plant Physiol ; 173(1): 326-337, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27920157

RESUMO

Cell signaling pathways mediated by leucine-rich repeat receptor-like kinases (LRR-RLKs) are essential for plant growth, development, and defense. The EMS1 (EXCESS MICROSPOROCYTES1) LRR-RLK and its small protein ligand TPD1 (TAPETUM DETERMINANT1) play a fundamental role in somatic and reproductive cell differentiation during early anther development in Arabidopsis (Arabidopsis thaliana). However, it is unclear whether other cell surface molecules serve as coregulators of EMS1. Here, we show that SERK1 (SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1) and SERK2 LRR-RLKs act redundantly as coregulatory and physical partners of EMS1. The SERK1/2 genes function in the same genetic pathway as EMS1 in anther development. Bimolecular fluorescence complementation, Förster resonance energy transfer, and coimmunoprecipitation approaches revealed that SERK1 interacted biochemically with EMS1. Transphosphorylation of EMS1 by SERK1 enhances EMS1 kinase activity. Among 12 in vitro autophosphorylation and transphosphorylation sites identified by tandem mass spectrometry, seven of them were found to be critical for EMS1 autophosphorylation activity. Furthermore, complementation test results suggest that phosphorylation of EMS1 is required for its function in anther development. Collectively, these data provide genetic and biochemical evidence of the interaction and phosphorylation between SERK1/2 and EMS1 in anther development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/enzimologia , Linhagem da Célula , Flores/citologia , Flores/enzimologia , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Epistasia Genética , Flores/genética , Flores/crescimento & desenvolvimento , Fluorescência , Modelos Biológicos , Mutação/genética , Fosforilação , Ligação Proteica
18.
Front Plant Sci ; 7: 1503, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27790226

RESUMO

Natural floral organ degeneration or abortion results in unisexual or fully sterile flowers, while abiotic stresses lead to sterility after initiation of floral reproductive organs. Since normal flower development is essential for plant sexual reproduction and crop yield, it is imperative to have a better understanding of plant sterility under regular and stress conditions. Here, we review the functions of ABC genes together with their downstream genes in floral organ degeneration and the formation of unisexual flowers in Arabidopsis and several agriculturally significant cereal grains. We further explore the roles of hormones, including auxin, brassinosteroids, jasmonic acid, gibberellic acid, and ethylene, in floral organ formation and fertility. We show that alterations in genes affecting hormone biosynthesis, hormone transport and perception cause loss of stamens/carpels, abnormal floral organ development, poor pollen production, which consequently result in unisexual flowers and male/female sterility. Moreover, abiotic stresses, such as heat, cold, and drought, commonly affect floral organ development and fertility. Sterility is induced by abiotic stresses mostly in male floral organ development, particularly during meiosis, tapetum development, anthesis, dehiscence, and fertilization. A variety of genes including those involved in heat shock, hormone signaling, cold tolerance, metabolisms of starch and sucrose, meiosis, and tapetum development are essential for plants to maintain normal fertility under abiotic stress conditions. Further elucidation of cellular, biochemical, and molecular mechanisms about regulation of fertility will improve yield and quality for many agriculturally valuable crops.

20.
PLoS Genet ; 12(8): e1006147, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27537183

RESUMO

A fundamental feature of sexual reproduction in plants and animals is the specification of reproductive cells that conduct meiosis to form gametes, and the associated somatic cells that provide nutrition and developmental cues to ensure successful gamete production. The anther, which is the male reproductive organ in seed plants, produces reproductive microsporocytes (pollen mother cells) and surrounding somatic cells. The microsporocytes yield pollen via meiosis, and the somatic cells, particularly the tapetum, are required for the normal development of pollen. It is not known how the reproductive cells affect the differentiation of these somatic cells, and vice versa. Here, we use molecular genetics, cell biological, and biochemical approaches to demonstrate that TPD1 (TAPETUM DETERMINANT1) is a small secreted cysteine-rich protein ligand that interacts with the LRR (Leucine-Rich Repeat) domain of the EMS1 (EXCESS MICROSPOROCYTES1) receptor kinase at two sites. Analyses of the expressions and localizations of TPD1 and EMS1, ectopic expression of TPD1, experimental missorting of TPD1, and ablation of microsporocytes yielded results suggesting that the precursors of microsporocyte/microsporocyte-derived TPD1 and pre-tapetal-cell-localized EMS1 initially promote the periclinal division of secondary parietal cells and then determine one of the two daughter cells as a functional tapetal cell. Our results also indicate that tapetal cells suppress microsporocyte proliferation. Collectively, our findings show that tapetal cell differentiation requires reproductive-cell-secreted TPD1, illuminating a novel mechanism whereby signals from reproductive cells determine somatic cell fate in plant sexual reproduction.


Assuntos
Proteínas de Arabidopsis/genética , Diferenciação Celular/genética , Flores/genética , Proteínas Quinases/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Ciclo Celular/genética , Flores/citologia , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Ligantes , Pólen/genética , Pólen/crescimento & desenvolvimento , Proteínas Quinases/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento
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