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Plants cope with various recurring stress conditions that often induce DNA damage, ultimately affecting plant genome integrity, growth, and productivity. The CROWDED NUCLEI (CRWN) family comprises lamin-like proteins with multiple functions, such as regulating gene expression, genome organization, and DNA damage repair in Arabidopsis (Arabidopsis thaliana). However, the mechanisms and consequences of CRWNs in DNA damage repair are largely unknown. Here, we reveal that CRWNs maintain genome stability by forming repairing nuclear bodies at DNA double-strand breaks. We demonstrate that CRWN1 and CRWN2 physically associate with the DNA damage repair proteins RAD51D and SUPPRESSOR OF NPR1-1 Inducible 1 (SNI1) and act in the same genetic pathway to mediate this process. Moreover, CRWN1 and CRWN2 partially localize at γ-H2AX foci upon DNA damage. Notably, CRWN1 and CRWN2 undergo liquid-liquid phase separation to form highly dynamic droplet-like structures with RAD51D and SNI1 to promote the DNA damage response (DDR). Collectively, our data shed light on the function of plant lamin-like proteins in the DDR and maintenance of genome stability.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Laminas/metabolismo , Proteínas Nucleares/metabolismo , Daño del ADN/genética , Reparación del ADN/genética , Inestabilidad Genómica , Proteínas Represoras/metabolismoRESUMEN
Reprograming of chromatin structures and changes in gene expression are critical for plant male gamete development, and epigenetic marks play an important role in these processes. Histone variant H3.3 is abundant in euchromatin and is largely associated with transcriptional activation. The precise function of H3.3 in gamete development remains unclear in plants. Here, we report that H3.3 is abundantly expressed in Arabidopsis anthers and its knockout mutant h3.3-1 is sterile due to male sterility. Transcriptome analysis of young inflorescence has identified 2348 genes downregulated in h3.3-1 mutant, among which 1087 target genes are directly bound by H3.3, especially at their 3' ends. As a group, this set of H3.3 targets is enriched in the reproduction-associated processes including male gamete generation, pollen sperm cell differentiation and pollen tube growth. The function of H3.3 in male gamete development is dependent on the Anti-Silencing Factor 1A/1B (ASF1A/1B)-Histone regulator A (HIRA)-mediated pathway. Our results suggest that ASF1A/1B-HIRA-mediated H3.3 deposition at its direct targets for transcription activation forms the regulatory networks responsible for male gamete development.
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Arabidopsis , Histonas , Histonas/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Semillas/metabolismo , Fertilidad , Células Germinativas/metabolismo , Cromatina/metabolismoRESUMEN
The Arabidopsis CROWDED NUCLEI (CRWN) family proteins form a lamina-like meshwork beneath the nuclear envelope with multiple functions, including maintenance of nuclear morphology, genome organization, DNA damage repair and transcriptional regulation. CRWNs can form homodimers/heterodimers through proteinâprotein interactions; however, the exact molecular mechanism of CRWN dimer formation and the diverse functions of different CRWN domains are not clear. In this report, we show that the N-terminal coiled-coil domain of CRWN1 facilitates its homodimerization and heterodimerization with the coiled-coil domains of CRWN2-CRWN4. We further demonstrated that the N-terminus but not the C-terminus of CRWN1 is sufficient to rescue the defect in nuclear morphology of the crwn1 crwn2 mutant to the WT phenotype. Moreover, both the N- and C-terminal fragments of CRWN1 are necessary for its normal function in the regulation of plant development. Collectively, our data shed light on the mechanism of plant lamina network formation and the functions of different domains in plant lamin-like proteins.
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Proteínas de Arabidopsis , Arabidopsis , Núcleo Celular , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/química , Núcleo Celular/metabolismo , Dominios Proteicos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/química , Multimerización de Proteína , Regulación de la Expresión Génica de las Plantas , MutaciónRESUMEN
Extreme environmental changes threaten plant survival and worldwide food production. In response to osmotic stress, the plant hormone abscisic acid (ABA) activates stress responses and restricts plant growth. However, the epigenetic regulation of ABA signaling and crosstalk between ABA and auxin are not well known. Here, we report that the histone variant H2A.Z-knockdown mutant in Arabidopsis Col-0, h2a.z-kd, has altered ABA signaling and stress responses. RNA-sequencing data showed that a majority of stress-related genes are activated in h2a.z-kd. In addition, we found that ABA directly promotes the deposition of H2A.Z on SMALL AUXIN UP RNAs (SAURs), and that this is involved in ABA-repression of SAUR expression. Moreover, we found that ABA represses the transcription of H2A.Z genes through suppressing the ARF7/19-HB22/25 module. Our results shed light on a dynamic and reciprocal regulation hub through H2A.Z deposition on SAURs and ARF7/19-HB22/25-mediated H2A.Z transcription to integrate ABA/auxin signaling and regulate stress responses in Arabidopsis.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Ácido Abscísico/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Histonas/metabolismo , Epigénesis Genética , ARN/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Auxin is a critical phytohormone that is involved in the regulation of most plant growth and developmental responses. In particular, epigenetic mechanisms, like histone modifications and DNA methylation, were reported to affect auxin biosynthesis and transport. However, the involvement of other epigenetic factors, such as histone variant H2A.Z, in the auxin-related developmental regulation remains unclear. We report that the histone variant H2A.Z knockdown mutant in Arabidopsis Col-0 ecotype, h2a.z-kd, has more lateral roots and weak gravitational responses related to auxin-regulated growth performances. Further study revealed that auxin promotes the eviction of H2A.Z from the auxin-responsive genes SMALL AUXIN-UP RNAs (SAURs) to activate their transcriptions. We found that IAA promotes the transcription of H2A.Z genes through HOMEOBOX PROTEIN 22/25 (AtHB22/25) transcription factors which work as downstream targets of ARF7/19 in auxin signaling. Double mutant of hb22 hb25 showed similar lateral root and gravitropism phenotypes to h2a.z-kd. Our results shed light on a reciprocal regulation hub through INOSITOL AUXOTROPHY 80-mediated H2A.Z eviction and ARF7/19-HB22/25-mediated H2A.Z transcription to modulate the activation of SAURs and plant growth in Arabidopsis.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Histonas/metabolismo , Retroalimentación , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas/metabolismo , Mutación/genéticaRESUMEN
Verticillium dahliae is a soil-borne fungus that causes vascular wilt on numerous plants worldwide. The fungus survives in the soil for up to 14 years by producing melanized microsclerotia. The protective function of melanin in abiotic stresses is well documented. Here, we found that the V. dahliae tetraspan transmembrane protein VdSho1, a homolog of the Saccharomyces cerevisiae Sho1, acts as an osmosensor, and is required for plant penetration and melanin biosynthesis. The deletion mutant ΔSho1 was incubated on a cellophane membrane substrate that mimics the plant epidermis, revealing that the penetration of ΔSho1 strain was reduced compared to the wild-type strain. Furthermore, VdSho1 regulates melanin biosynthesis by a signalling mechanism requiring a kinase-kinase signalling module of Vst50-Vst11-Vst7. Strains, ΔVst50, ΔVst7 and ΔVst11 also displayed defective penetration and melanin production like the ΔSho1 strain. Defects in penetration and melanin production in ΔSho1 were restored by overexpression of Vst50, suggesting that Vst50 lies downstream of VdSho1 in the regulatory pathway governing penetration and melanin biosynthesis. Data analyses revealed that the transmembrane portion of VdSho1 was essential for both membrane penetration and melanin production. This study demonstrates that Vst50-Vst11-Vst7 module regulates VdSho1-mediated plant penetration and melanin production in V. dahliae, contributing to virulence.
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Proteínas Fúngicas/metabolismo , Gossypium/microbiología , Melaninas/biosíntesis , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Enfermedades de las Plantas/microbiología , Verticillium/metabolismo , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , Metabolismo Secundario , Eliminación de Secuencia , Transducción de Señal , Verticillium/genética , Verticillium/patogenicidad , VirulenciaRESUMEN
Verticillium dahliae is a broad host-range pathogen that causes vascular wilts in plants. Interactions between three hosts and specific V. dahliae genotypes result in severe defoliation. The underlying mechanisms of defoliation are unresolved. Genome resequencing, gene deletion and complementation, gene expression analysis, sequence divergence, defoliating phenotype identification, virulence analysis, and quantification of V. dahliae secondary metabolites were performed. Population genomics previously revealed that G-LSR2 was horizontally transferred from the fungus Fusarium oxysporum f. sp. vasinfectum to V. dahliae and is exclusively found in the genomes of defoliating (D) strains. Deletion of seven genes within G-LSR2, designated as VdDf genes, produced the nondefoliation phenotype on cotton, olive, and okra but complementation of two genes restored the defoliation phenotype. Genes VdDf5 and VdDf6 associated with defoliation shared homology with polyketide synthases involved in secondary metabolism, whereas VdDf7 shared homology with proteins involved in the biosynthesis of N-lauroylethanolamine (N-acylethanolamine (NAE) 12:0), a compound that induces defoliation. NAE overbiosynthesis by D strains also appears to disrupt NAE metabolism in cotton by inducing overexpression of fatty acid amide hydrolase. The VdDfs modulate the synthesis and overproduction of secondary metabolites, such as NAE 12:0, that cause defoliation either by altering abscisic acid sensitivity, hormone disruption, or sensitivity to the pathogen.
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Genómica , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Verticillium/genética , Verticillium/patogenicidad , Secuencia de Bases , Etanolaminas/metabolismo , Genes Fúngicos , Variación Genética , Genoma Fúngico , Gossypium/genética , Ácidos Láuricos/metabolismo , Modelos Biológicos , Familia de Multigenes , Fenotipo , Metabolismo Secundario/genéticaRESUMEN
Water and organic amendments are the two most important factors that control methane (CH4) emissions from rice fields, the combined effect of which on CH4 emissions has been rarely studied. Thus, a field experiment in a split-plot design was conducted to investigate the combined effect of straw and water management on CH4 emissions. Main plots had water treatments: continuous flooding (CF), flooding - midseason drying - flooding (FDF), and flooding for transplanting - rainfed (RF); and subplots had straw treatments: straw incorporated into soil (SI), straw mulching (SM), and without straw. Results showed that the presence of water layer led to substantial increase in CH4 emissions which were enhanced by straw application. Cumulative CH4 emissions were influenced by water, straw, and their interactions significantly (Pâ¯<â¯0.05). The cumulative CH4 emissions were 505.3, 241.2, and 56.5â¯kgâ¯ha-1 for CF, FDF, and RF, respectively. By contrast, SI under CF, FDF, and RF increased CH4 emissions by 265.4, 271.4, and 175.6â¯kgâ¯ha-1, respectively. And SM under CF, FDF, and RF increased CH4 emissions by 213.3, 112.8, and 14.6â¯kgâ¯ha-1, respectively. The results indicated that SM resulted in less CH4 emissions compared with SI, especially in plots frequently with absence of water layer. Besides, SM had a potential to increase rice yield in rice paddies that had a lack of water. Therefore, in-season straw application should be avoided in lowland rice paddies, and straw mulching is practical in rice paddies lack of water.
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Oryza , Agricultura , Metano , Óxido Nitroso , Suelo , AguaRESUMEN
Objective: To explore the relationship between the laccase activity and growth of Ganoderma spp.,to screen the highproducing laccase strains. Methods: The mycelium was cultured in PDA solid medium,and the laccase activity was measured by ABTS+method. The content of polysaccharide was determined by phenol sulfuric acid method. Results: Ganoderma gibbosum grew more rapidly in the early stage,and the laccase activity reached maximum( 1 476. 64 U/g) in the 4th day,which was 11. 37 times larger than that of sweet Ganoderma lucidum. Ganoderma gibbosum had the significant advantage after a comprehensive analysis. The polysaccharide content of Ganoderma lucidum of Shinshu was lower; the growth rate of Ganoderma lucidum strain S3 was stable, and the content of polysaccharide was medium. Conclusion: There are some differences in the growth rate of Ganoderma spp., and there is a certain correlation between the laccase activity and growth. Ganoderma gibbosum is the highest-producing laccase strain among the screening strains.
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Aggregation-induced emission (AIE) materials are attracting great attention in biomedical fields such as sensors, bioimaging, and cancer treatment, et al. due to their strong fluorescence emission in the aggregated state. In this contribution, a series of tetraphenylene-acetonitrile AIE compounds with D-A-D' structures were synthesized by Suzuki coupling reaction and Knoevenagel condensation, and their relationship of chemical structure and fluorescence properties was investigated in detail, among which TPPA compound was selected as the monomer owing to the longest emission wavelength at about 530â¯nm with low energy band gap ΔE 3.09â¯eV of neutral TPPA and 1.43â¯eV of protonated TPPA. Novel amphiphilic AIE PEG-TA copolymers were prepared by RAFT polymerization of TPPA and PEGMA with about 1.44×104 Mw and narrow PDI, and the molar ratio of TPPA in the PEG-TA1 and PEG-TA2 copolymers was about 23.4â¯% and 29.6â¯%. The as-prepared PEG-TA copolymers would self-assembled in aqueous solution to form core-shell structures with a diameter of 150-200â¯nm, and their emission wavelength could reversibly convert from 545â¯nm to 650â¯nm with excellent pH sensitivity. The CLSM images showed that the PEG-TA FONs and PTX drugs-loaded PTX-TA FONs could be endocytosed by cells and mainly enriched in the cytoplasm, and CCK-8 results showed that the PEG-TA FONs had excellent biocompatibility but PTX-TA FONs had high inhibition ratio for A549 cells, moreover, the flow cytometry also showed that PTX-TA FONs could result in the apoptosis of A549 cells with some extent anti-tumor effect.
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Sugar is a primary determinant of citrus fruit flavour, but undergoes varied accumulation processes across different citrus varieties owing to high genetic variability. Sucrose phosphate synthase (SPS), a key enzyme in glucose metabolism, plays a crucial role in this context. Despite its significance, there is limited research on sugar component quality and the expression and regulatory prediction of SPS genes during citrus fruit development. Therefore, we analysed the sugar quality formation process in 'Kiyomi' and 'Succosa', two citrus varieties, and performed a comprehensive genome-wide analysis of citrus CsSPSs. We observed that the accumulation of sugar components significantly differs between the two varieties, with the identification of four CsSPSs in citrus. CsSPS sequences were highly conserved, featuring typical SPS protein domains. Expression analysis revealed a positive correlation between CsSPS expression and sugar accumulation in citrus fruits. However, CsSPS expression displays specificity to different citrus tissues and varieties. Transcriptome co-expression network analysis suggests the involvement of multiple transcription factors in shaping citrus fruit sugar quality through the regulation of CsSPSs. Notably, the expression levels of four CsWRKYs (CsWRKY2, CsWRKY20, CsWRKY28, CsWRKY32), were significantly positively correlated with CsSPSs and CsWRKY20 might can activate sugar accumulation in citrus fruit through CsSPS2. Collectively, we further emphasize the potential importance of CsWRKYs in citrus sugar metabolism, our findings serve as a reference for understanding sugar component formation and predicting CsSPS expression and regulation during citrus fruit development.
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'Fengtang' plums soften quickly and lose flavor after harvest. This study comprehensively evaluated the effect of exogenous melatonin on the fruit quality of 'Fengtang' plums. According to our findings, exogenous melatonin prevented plum fruit from losing water, delayed the decline in firmness, and preserved a high TSS/TA level. Additionally, exogenous melatonin also enhanced the activity of antioxidant enzymes and increased the non-enzymatic antioxidants, thereby further increasing the antioxidant capacity of plum fruit. Notably, exogenous melatonin delayed the degradation of covalent soluble pectin (CSP), cellulose, and hemicellulose, as well as the rise in water-soluble pectin (WSP) concentration and the activity of cell wall degrading enzymes. Further investigation using atomic force microscopy (AFM) revealed that the chain-like structure of ionic-soluble pectin (ISP) and the self-assembly network structures of CSP were depolymerized, and melatonin treatment retarded the depolymerization of pectin structures. Our results showed that exogenous melatonin preserved the postharvest quality of plum fruits by controlling fruit softness and antioxidant capacity during storage.
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Histone H2A monoubiquitination (H2Aub1) functions as a conserved posttranslational modification in eukaryotes to maintain gene expression and guarantee cellular identity. Arabidopsis H2Aub1 is catalyzed by the core components AtRING1s and AtBMI1s of polycomb repressive complex 1 (PRC1). Because PRC1 components lack known DNA binding domains, it is unclear how H2Aub1 is established at specific genomic locations. Here, we show that the Arabidopsis cohesin subunits AtSYN4 and AtSCC3 interact with each other, and AtSCC3 binds to AtBMI1s. H2Aub1 levels are reduced in atsyn4 mutant or AtSCC3 artificial microRNA knockdown plants. ChIP-seq assays indicate that most binding events of AtSYN4 and AtSCC3 are associated with H2Aub1 along the genome where transcription is activated independently of H3K27me3. Finally, we show that AtSYN4 binds directly to the G-box motif and directs H2Aub1 to these sites. Our study thus reveals a mechanism for cohesin-mediated recruitment of AtBMI1s to specific genomic loci to mediate H2Aub1.
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Proteínas de Arabidopsis , Arabidopsis , Histonas , Complejo Represivo Polycomb 1 , Procesamiento Proteico-Postraduccional , Ubiquitinación , CohesinasRESUMEN
Sugars and organic acids are the main factors determining the flavor of citrus fruit. The WRKY transcription factor family plays a vital role in plant growth and development. However, there are still few studies about the regulation of citrus WRKY transcription factors (CsWRKYs) on sugars and organic acids in citrus fruit. In this work, a genome-wide analysis of CsWRKYs was carried out in the citrus genome, and a total of 81 CsWRKYs were identified, which contained conserved WRKY motifs. Cis-regulatory element analysis revealed that most of the CsWRKY promoters contained several kinds of hormone-responsive and abiotic-responsive cis-elements. Furthermore, gene expression analysis and fruit quality determination showed that multiple CsWRKYs were closely linked to fruit sugars and organic acids with the development of citrus fruit. Notably, transcriptome co-expression network analysis further indicated that three CsWRKYs, namely, CsWRKY3, CsWRKY47, and CsWRKY46, co-expressed with multiple genes involved in various pathways, such as Pyruvate metabolism and Citrate cycle. These CsWRKYs may participate in the metabolism of fruit sugars and organic acids by regulating carbohydrate metabolism genes in citrus fruit. These findings provide comprehensive knowledge of the CsWRKY family on the regulation of fruit quality.
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The arms race between fungal pathogens and plant hosts involves recognition of fungal effectors to induce host immunity. Although various fungal effectors have been identified, the effector functions of ribonucleases are largely unknown. Herein, we identified a ribonuclease secreted by Verticillium dahliae (VdRTX1) that translocates into the plant nucleus to modulate immunity. The activity of VdRTX1 causes hypersensitive response (HR)-related cell death in Nicotiana benthamiana and cotton. VdRTX1 possesses a signal peptide but is unlikely to be an apoplastic effector because its nuclear localization in the plant is necessary for cell death induction. Knockout of VdRTX1 significantly enhanced V. dahliae virulence on tobacco while V. dahliae employs the known suppressor VdCBM1 to escape the immunity induced by VdRTX1. VdRTX1 homologs are widely distributed in fungi but transient expression of 24 homologs from other fungi did not yield cell death induction, suggesting that this function is specific to the VdRTX1 in V. dahliae. Expression of site-directed mutants of VdRTX1 in N. benthamiana leaves revealed conserved ligand-binding sites that are important for VdRTX1 function in inducing cell death. Thus, VdRTX1 functions as a unique HR-inducing effector in V. dahliae that contributes to the activation of plant immunity.
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Verticillium , Acremonium , Gossypium/genética , Enfermedades de las Plantas/microbiología , Inmunidad de la Planta , Ribonucleasas/metabolismo , Nicotiana/microbiologíaRESUMEN
B-box transcription factors (BBXs) are important regulators of flowering, photomorphogenesis, shade-avoidance, abiotic and biotic stresses and plant hormonal pathways. In Arabidopsis, 32 BBX proteins have been identified and classified into five groups based on their structural domains. Little is known about the fifth group members (BBX26-BBX32) and the detailed molecular mechanisms relevant to their functions. Here we identified B-box transcription factor 28 (BBX28) that interacts with Constans (CO), a transcriptional activator of Flowering Locus T (FT). Overexpressing BBX28 leads to late flowering with dramatically decreased FT transcription, and bbx28 deficient mutant displays a weak early flowering phenotype under long days (LD), indicating that BBX28 plays a negative and redundant role in flowering under LD. Additionally, the interaction between BBX28 and CO decreases the recruitment of CO to FT locus without affecting the transcriptional activation activity of CO. Moreover, the N-terminal cysteines, especially those within the B-box domain, are indispensable for the heterodimerization between BBX28 and CO and activation of CO on FT transcription. Genetic evidences show that the later flowering caused by BBX28 overexpression is compromised by CO ectopic expression. Collectively, these results supported that BBX28 functions with CO and FT to negatively regulate Arabidopsis flowering, in which the N-terminal conserved cysteines of BBX28 might play a central role.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiología , Proteínas de Unión al ADN/metabolismo , Flores/fisiología , Factores de Transcripción/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Células Cultivadas , Regulación de la Expresión Génica de las Plantas , Proteínas de Dominio MADS/genética , Proteínas de Dominio MADS/metabolismo , Mutación , Fenotipo , Fenómenos Fisiológicos de las Plantas , Plantas Modificadas Genéticamente , Unión Proteica , Factores de Transcripción/genéticaRESUMEN
Integrated rice-duck farming (IRDF) has proven to decrease methane (CH4) emissions due to increased dissolved oxygen caused by duck bioturbation. The duck bioturbation, however, also causes many bubbles of CH4 that were overlooked in previous studies. Therefore, it is uncertain whether IRDF could decrease CH4 emissions. We hypothesize that the effect of IRDF on CH4 emissions is related with the intensity of duck bioturbation. We simulated duck's disturbance (trampling and foraging) by stirring and aerating the surface soil in flooded rice fields. Three treatments were disturbed with an interval of 12 h (D12), 24 h (D24), and 48 h (D48), respectively, with non-disturbance as the control (CK). CH4 emissions as bubbles during the disturbance period (CH4-A) were investigated. Besides, CH4 emissions were investigated every 2 h (CH4-B), which lasted for 4 days during the rice elongation stage. Compared with CK, D12, D24, and D48 decreased CH4-B emissions by 17.1%, 14.0%, and 10.1%, respectively. However, the CH4-A emissions under D12, D24, and D48 were equivalent to 14.2%, 14.0%, and 11.9% of CH4 emissions under CK, respectively. On the whole, simulated duck bioturbation had limited effects on the reduction of total CH4 emissions.
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Metano/análisis , Óxido Nitroso/análisis , Agricultura , Animales , China , Patos , Granjas , Metano/química , Óxido Nitroso/química , Oryza , Oxígeno , SueloRESUMEN
Secreted small cysteine-rich proteins (SCPs) play a critical role in modulating host immunity in plant-pathogen interactions. Bioinformatic analyses showed that the fungal pathogen Verticillium dahliae encodes more than 100 VdSCPs, but their roles in host-pathogen interactions have not been fully characterized. Transient expression of 123 VdSCP-encoding genes in Nicotiana benthamiana identified three candidate genes involved in host-pathogen interactions. The expression of these three proteins, VdSCP27, VdSCP113, and VdSCP126, in N. benthamiana resulted in cell death accompanied by a reactive oxygen species burst, callose deposition, and induction of defence genes. The three VdSCPs mainly localized to the periphery of the cell. BAK1 and SOBIR1 (associated with receptor-like protein) were required for the immunity triggered by these three VdSCPs in N. benthamiana. Site-directed mutagenesis showed that cysteine residues that form disulphide bonds are essential for the functioning of VdSCP126, but not VdSCP27 and VdSCP113. VdSCP27, VdSCP113, and VdSCP126 individually are not essential for V. dahliae infection of N. benthamiana and Gossypium hirsutum, although there was a significant reduction of virulence on N. benthamiana and G. hirsutum when inoculated with the VdSCP27/VdSCP126 double deletion strain. These results illustrate that the SCPs play a critical role in the V. dahliae-plant interaction via an intrinsic virulence function and suppress immunity following infection.
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Ascomicetos/patogenicidad , Moléculas de Patrón Molecular Asociado a Patógenos/metabolismo , Enfermedades de las Plantas/microbiología , Regulación de la Expresión Génica de las Plantas , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/fisiología , Enfermedades de las Plantas/genética , VirulenciaRESUMEN
Improving genetic resistance is a preferred method to manage Verticillium wilt of cotton and other hosts. Identifying host resistance is difficult because of the dearth of resistance genes against this pathogen. Previously, a novel candidate gene involved in Verticillium wilt resistance was identified by a genome-wide association study using a panel of Gossypium hirsutum accessions. In this study, we cloned the candidate resistance gene from cotton that encodes a protein sharing homology with the TIR-NBS-LRR receptor-like defence protein DSC1 in Arabidopsis thaliana (hereafter named GhDSC1). GhDSC1 expressed at higher levels in response to Verticillium wilt and jasmonic acid (JA) treatment in resistant cotton cultivars as compared to susceptible cultivars and its product was localized to nucleus. The transfer of GhDSC1 to Arabidopsis conferred Verticillium resistance in an A. thaliana dsc1 mutant. This resistance response was associated with reactive oxygen species (ROS) accumulation and increased expression of JA-signalling-related genes. Furthermore, the expression of GhDSC1 in response to Verticillium wilt and JA signalling in A. thaliana displayed expression patterns similar to GhCAMTA3 in cotton under identical conditions, suggesting a coordinated DSC1 and CAMTA3 response in A. thaliana to Verticillium wilt. Analyses of GhDSC1 sequence polymorphism revealed a single nucleotide polymorphism (SNP) difference between resistant and susceptible cotton accessions, within the P-loop motif encoded by GhDSC1. This SNP difference causes ineffective activation of defence response in susceptible cultivars. These results demonstrated that GhDSC1 confers Verticillium resistance in the model plant system of A. thaliana, and therefore represents a suitable candidate for the genetic engineering of Verticillium wilt resistance in cotton.