RESUMO
Hibiscus sabdariffa L. is a widely cultivated herbaceous plant with diverse applications in food, tea, fiber, and medicine. In this study, we present a high-quality genome assembly of H. sabdariffa using more than 33 Gb of high-fidelity (HiFi) long-read sequencing data, corresponding to â¼20× depth of the genome. We obtained 3 genome assemblies of H. sabdariffa: 1 primary and 2 partially haplotype-resolved genome assemblies. These genome assemblies exhibit N50 contig lengths of 26.25, 11.96, and 14.50 Mb, with genome coverage of 141.3, 86.0, and 88.6%, respectively. We also utilized 26 Gb of total RNA sequencing data to predict 154k, 79k, and 87k genes in the respective assemblies. The completeness of the primary genome assembly and its predicted genes was confirmed by the benchmarking universal single-copy ortholog analysis with a completeness rate of 99.3%. Based on our high-quality genomic resources, we constructed genetic networks for phenylpropanoid and flavonoid metabolism and identified candidate biosynthetic genes, which are responsible for producing key intermediates of roselle-specific medicinal natural products. Our comprehensive genomic and functional analysis opens avenues for further exploration and application of valuable natural products in H. sabdariffa.
Assuntos
Produtos Biológicos , Genoma de Planta , Hibiscus , Hibiscus/genética , Produtos Biológicos/metabolismo , Anotação de Sequência Molecular , Genômica/métodos , Plantas Medicinais/genética , Plantas Medicinais/metabolismoRESUMO
Plants, as a sessile organism, produce various secondary metabolites to interact with the environment. These chemicals have fascinated the plant science community because of their ecological significance and notable biological activity. However, predicting the complete biosynthetic pathways from target molecules to metabolic building blocks remains a challenge. Here, we propose retrieval-augmented dual-view retrosynthesis (READRetro) as a practical bio-retrosynthesis tool to predict the biosynthetic pathways of plant natural products. Conventional bio-retrosynthesis models have been limited in their ability to predict biosynthetic pathways for natural products. READRetro was optimized for the prediction of complex metabolic pathways by incorporating cutting-edge deep learning architectures, an ensemble approach, and two retrievers. Evaluation of single- and multi-step retrosynthesis showed that each component of READRetro significantly improved its ability to predict biosynthetic pathways. READRetro was also able to propose the known pathways of secondary metabolites such as monoterpene indole alkaloids and the unknown pathway of menisdaurilide, demonstrating its applicability to real-world bio-retrosynthesis of plant natural products. For researchers interested in the biosynthesis and production of secondary metabolites, a user-friendly website (https://readretro.net) and the open-source code of READRetro have been made available.
Assuntos
Produtos Biológicos , Vias Biossintéticas , Produtos Biológicos/metabolismo , Plantas/metabolismo , Metabolismo Secundário , Aprendizado ProfundoRESUMO
This study explores how elevated carbon dioxide (CO2) levels affects the growth and defense mechanisms of plants. We focused on Aristolochia contorta Bunge (Aristolochiaceae), a wild plant that exhibits growth reduction under elevated CO2 in the previous study. The plant has Sericinus montela Gray (Papilionidae) as a specialist herbivore. By analyzing primary metabolites, understanding both the growth and defense response of plants to herbivory under elevated CO2 conditions is possible. The experiment was conducted across four groups, combining two CO2 concentration conditions (ambient CO2 and elevated CO2) with two herbivory conditions (herbivory treated and untreated). Although many plants exhibit increased growth under elevated CO2 levels, A. contorta exhibited reduced growth with lower height, dry weight, and total leaf area. Under herbivory, A. contorta triggered both localized and systemic responses. More primary metabolites exhibited significant differences due to herbivory treatment in systemic tissue than local leaves that herbivory was directly treated. Herbivory under elevated CO2 level triggered more significant responses in primary metabolites (17 metabolites) than herbivory under ambient CO2 conditions (five metabolites). Several defense-related metabolites exhibited higher concentrations in the roots and lower concentrations in the leaves in response to the herbivory treatment in the elevated CO2 group. This suggests a potential intensification of defensive responses in the underground parts of the plant under elevated CO2 levels. Our findings underscore the importance of considering both abiotic and biotic factors in understanding plant responses to environmental changes. The adaptive strategies of A. contorta suggest a complex response mechanism to elevated CO2 and herbivory pressures.
RESUMO
The environment has been identified as an origin, reservoir, and transmission route of antibiotic resistance genes (ARGs). Among diverse environments, freshwater environments have been recognized as pivotal in the transmission of ARGs between opportunistic pathogens and autochthonous bacteria such as Aeromonas spp. In this study, five environmental strains of Aeromonas spp. exhibiting multidrug resistance (MDR) were selected for whole-genome sequencing to ascertain their taxonomic assignment at the species-level and to delineate their ARG repertoires. Analyses of their genomes revealed the presence of one protein almost identical to AhQnr (A. hydrophila Qnr protein) and four novel proteins similar to AhQnr. To scrutinize the classification and taxonomic distribution of these proteins, all Aeromonas genomes deposited in the NCBI RefSeq genome database (1,222 genomes) were investigated. This revealed that these Aeromonas Qnr (AQnr) proteins are conserved intrinsic resistance determinants of the genus, exhibiting species-specific diversity. Additionally, structure prediction and analysis of contribution to quinolone resistance by AQnr proteins of the isolates, confirmed their functionality as quinolone resistance determinants. Given the origin of mobile qnr genes from aquatic bacteria and the crucial role of Aeromonas spp. in ARG dissemination in aquatic environments, a thorough understanding and strict surveillance of AQnr families prior to the clinical emergence are imperative. In this study, using comparative genome analyses and functional characterization of AQnr proteins in the genus Aeromonas, novel Aeromonas ARGs requiring surveillance has suggested.
Assuntos
Aeromonas , Antibacterianos , Proteínas de Bactérias , Quinolonas , Sequenciamento Completo do Genoma , Aeromonas/genética , Aeromonas/efeitos dos fármacos , Aeromonas/classificação , Quinolonas/farmacologia , Proteínas de Bactérias/genética , Antibacterianos/farmacologia , Filogenia , Genoma Bacteriano , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana Múltipla/genética , Farmacorresistência Bacteriana/genéticaRESUMO
BACKGROUND: Preingestive behavioral modulations of herbivorous insects on the host plant are abundant over insect taxa. Those behaviors are suspected to have functions such as deactivation of host plant defenses, nutrient accumulation, or modulating plant-mediated herbivore interactions. To understand the functional consequence of behavioral modulation of insect herbivore, we studied the girdling behavior of Phytoecia rufiventris Gautier (Lamiinae; Cerambycidae) on its host plant Erigeron annuus L. (Asteraceae) that is performed before endophytic oviposition in the stem. RESULTS: The girdling behavior significantly increased the larval performance in both field monitoring and lab experiment. The upper part of the girdled stem exhibited lack of jasmonic acid induction upon larval attack, lowered protease inhibitor activity, and accumulated sugars and amino acids in compared to non-girdled stem. The girdling behavior had no effect on the larval performance of a non-girdling longhorn beetle Agapanthia amurensis, which also feeds on the stem of E. annuus during larval phase. However, the girdling behavior decreased the preference of A. amurensis females for oviposition, which enabled P. rufiventris larvae to avoid competition with A. amurensis larvae. CONCLUSIONS: In conclusion, the girdling behavior modulates plant physiology and morphology to provide a modulated food source for larva and hide it from the competitor. Our study implies that the insect behavior modulations can have multiple functions, providing insights into adaptation of insect behavior in context of plant-herbivore interaction.
Assuntos
Besouros , Animais , Feminino , Larva/fisiologia , Insetos/fisiologia , Plantas , Herbivoria/fisiologiaRESUMO
Plants exhibit an astonishing ability to regulate organ regeneration upon wounding. Excision of leaf explants promotes the biosynthesis of indole-3-acetic acid (IAA), which is polar-transported to excised regions, where cell fate transition leads to root founder cell specification to induce de novo root regeneration. The regeneration capacity of plants has been utilized to develop in vitro tissue culture technologies. Here, we report that IAA accumulation near the wounded site of leaf explants is essential for callus formation on 2,4-dichlorophenoxyacetic acid (2,4-D)-rich callus-inducing medium (CIM). Notably, a high concentration of 2,4-D does not compensate for the action of IAA because of its limited efflux; rather, it lowers IAA biosynthesis via a negative feedback mechanism at an early stage of in vitro tissue culture, delaying callus initiation. The auxin negative feedback loop in CIM-cultured leaf explants is mediated by an auxin-inducible APETALA2 transcription factor, ENHANCER OF SHOOT REGENERATION 2 (ESR2), along with its interacting partner HISTONE DEACETYLASE 6 (HDA6). The ESR2-HDA6 complex binds directly to, and removes the H3ac mark from, the YUCCA1 (YUC1), YUC7, and YUC9 loci, consequently repressing auxin biosynthesis and inhibiting cell fate transition on 2,4-D-rich CIM. These findings indicate that negative feedback regulation of auxin biosynthesis by ESR2 and HDA6 interferes with proper cell fate transition and callus initiation.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácidos Indolacéticos , Folhas de Planta , Ácido 2,4-Diclorofenoxiacético/metabolismo , Ácido 2,4-Diclorofenoxiacético/farmacologia , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/metabolismo , Histona Desacetilases/genética , Ácidos Indolacéticos/metabolismo , Folhas de Planta/metabolismo , Técnicas de Cultura de Tecidos , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genéticaRESUMO
The urgent demand for effective countermeasures against metallo-ß-lactamases (MBLs) necessitates development of novel metallo-ß-lactamase inhibitors (MBLIs). This study is dedicated to identifying critical chemical moieties within previously developed MBLIs, and critical MBLs should serve as the target in MBLI evaluations. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a systematic literature analysis was conducted, and the NCBI RefSeq genome database was exploited to access the abundance profile and taxonomic distribution of MBLs and their variant types. Through the implementation of two distinct systematic approaches, we elucidated critical chemical moieties of MBLIs, providing pivotal information for rational drug design. We also prioritised MBLs and their variant types, highlighting the imperative need for comprehensive testing to ensure the potency and efficacy of the newly developed MBLIs. This approach contributes valuable information to advance the field of antimicrobial drug discovery.
Assuntos
Inibidores de beta-Lactamases , beta-Lactamases , Inibidores de beta-Lactamases/farmacologia , Antibacterianos/farmacologia , Desenho de FármacosRESUMO
Inflammasomes are multiprotein complexes involved in the host immune response to pathogen infections. Thus, inflammasomes participate in many conditions, such as acne. Recently, it was shown that NETosis, a type of neutrophil cell death, is induced by bacterial infection and is involved in inflammatory diseases such as delayed wound healing in patients with diabetes. However, the relationship between inflammasomes and NETosis in the pathogenesis of inflammatory diseases has not been well studied. In this study, we determined whether NETosis is induced in P. acnes-induced skin inflammation and whether activation of the nucleotide-binding domain, leucine-rich family, and pyrin domain-containing-3 (NLRP3) inflammasome is one of the key factors involved in NETosis induction in a mouse model of acne skin inflammation. We found that NETosis was induced in P. acnes-induced skin inflammation in mice and that inhibition of NETosis ameliorated P. acnes-induced skin inflammation. In addition, our results demonstrated that inhibiting inflammasome activation could suppress NETosis induction in mouse skin. These results indicate that inflammasomes and NETosis can interact with each other to induce P. acnes-induced skin inflammation and suggest that targeting NETosis could be a potential treatment for inflammasome-mediated diseases as well as NETosis-related diseases.
Assuntos
Acne Vulgar , Armadilhas Extracelulares , Inflamassomos , Inflamação , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Inflamassomos/metabolismo , Armadilhas Extracelulares/metabolismo , Armadilhas Extracelulares/imunologia , Acne Vulgar/imunologia , Camundongos , Inflamação/imunologia , Inflamação/patologia , Pele/patologia , Pele/imunologia , Neutrófilos/imunologia , Neutrófilos/metabolismo , Camundongos Endogâmicos C57BL , Humanos , Modelos Animais de DoençasRESUMO
Mosses are vital components of ecosystems, exhibiting remarkable adaptability across diverse habitats from deserts to polar ice caps. Sanionia uncinata (Hedw.) Loeske, a dominant Antarctic moss survives extreme environmental condition through perennial lifecycles involving growth and dormancy alternation. This study explores genetic controls and molecular mechanisms enabling S. uncinata to cope with seasonality of the Antarctic environment. We analysed the seasonal transcriptome dynamics of S. uncinata collected monthly from February 2015 to January 2016 in King George Island, Antarctica. Findings indicate that genes involved in plant growth were predominantly upregulated in Antarctic summer, while those associated with protein synthesis and cell cycle showed marked expression during the winter-to-summer transition. Genes implicated in cellular stress and abscisic acid signalling were highly expressed in winter. Further, validation included a comparison of the Antarctic field transcriptome data with controlled environment simulation of Antarctic summer and winter temperatures, which revealed consistent gene expression patterns in both datasets. This proposes a seasonal gene regulatory model of S. uncinate to understand moss adaptation to extreme environments. Additionally, this data set is a valuable resource for predicting genetic responses to climatic fluctuations, enhancing our knowledge of Antarctic flora's resilience to global climate change.
Assuntos
Briófitas , Briófitas/genética , Ecossistema , Regiões Antárticas , Neve , Ambientes Extremos , Perfilação da Expressão GênicaRESUMO
The effect of tempering temperature on the hydrogen embrittlement characteristics of SCM440 tempered martensitic steels was investigated in terms of their microstructure and hydrogen desorption behavior. The microstructures were characterized using scanning and transmission electron microscopy, as well as X-ray diffraction and electron backscattered diffraction analysis. Thermal desorption analysis (TDA) was performed to examine the amount and trapping behavior of hydrogen. The cementite morphology of the SCM440 tempered martensitic steels gradually changed from a long lamellar shape to a segmented short-rod shape with an increasing tempering temperature. A slow strain rate tensile test was conducted after electrochemical hydrogen charging to evaluate the hydrogen embrittlement resistance. The hydrogen embrittlement resistance of the SCM440 tempered martensitic steels increased with an increasing tempering temperature because of the decrease in the fraction of the low-angle grain boundaries and dislocation density. The low-angle grain boundaries and dislocations, which acted as reversible hydrogen trap sites, were critical factors in determining the hydrogen embrittlement resistance, and this was supported by the decreased diffusible hydrogen content as measured by TDA. Fine carbides formed in the steel tempered at a relatively higher temperature acted as irreversible hydrogen trap sites and contributed to improving the hydrogen embrittlement resistance. Our findings can suggest that the tempering temperature of SCM440 tempered martensitic steel plays an important role in determining its hydrogen embrittlement resistance.
RESUMO
Genome editing approaches, particularly the CRISPR/Cas9 technology, are becoming state-of-the-art for trait development in numerous breeding programs. Significant advances in improving plant traits are enabled by this influential tool, especially for disease resistance, compared to traditional breeding. One of the potyviruses, the turnip mosaic virus (TuMV), is the most widespread and damaging virus that infects Brassica spp. worldwide. We generated the targeted mutation at the eIF(iso)4E gene in the TuMV-susceptible cultivar "Seoul" using CRISPR/Cas9 to develop TuMV-resistant Chinese cabbage. We detected several heritable indel mutations in the edited T0 plants and developed T1 through generational progression. It was indicated in the sequence analysis of the eIF(iso)4E-edited T1 plants that the mutations were transferred to succeeding generations. These edited T1 plants conferred resistance to TuMV. It was shown with ELISA analysis the lack of accumulation of viral particles. Furthermore, we found a strong negative correlation (r = -0.938) between TuMV resistance and the genome editing frequency of eIF(iso)4E. Consequently, it was revealed in this study that CRISPR/Cas9 technique can expedite the breeding process to improve traits in Chinese cabbage plants.
RESUMO
The western flower thrips, Frankliniella occidentalis, is an insect pest, and its aggregation pheromone (AP) plays a crucial role in the recruitment of both sexes. A novel pheromone biosynthesis-activating neuropeptide (PBAN)-like gene is encoded in F. occidentalis genome, but its physiological function has yet to be elucidated. This study hypothesized the physiological role played by PBAN in mediating AP production. AP has been known to be produced only by male adults in F. occidentalis. Surprisingly, our extraction of headspace volatiles contained two AP components in females as well as in males with similar composition. PBAN injection elevated the AP production whereas RNA interference (RNAi) of the gene expression suppressed the AP production in both sexes. A biosynthetic pathway to produce AP components were predicted and the enzymes catalyzing the main steps were confirmed in their expressions. Individual RNAi treatments of these genes significantly suppressed AP production. RNAi of PBAN gene downregulated the expressions of these biosynthesis-associated genes in both sexes. These results suggest that the novel neuropeptide acts as PBAN mediating AP production through stimulating its biosynthetic machinery in F. occidentalis.
Assuntos
Mariposas , Neuropeptídeos , Atrativos Sexuais , Masculino , Feminino , Animais , Feromônios/metabolismo , Neuropeptídeos/metabolismo , Interferência de RNA , Mariposas/fisiologia , Atrativos Sexuais/metabolismoRESUMO
The CRISPR/Cas9 system is an extremely powerful tool for targeted mutagenesis in plants. However, plant genome editing relies on the labor-intensive plant regeneration method for generating gene-edited plants. To overcome this bottleneck, several virus-induced genome editing (VIGE) techniques have been developed. The VIGE system aims to induce targeted mutations in germ cells without plant regeneration. However, due to the delivery issues of a large Cas9 protein, scientists focus on developing a virus-mediated delivery system for guide RNA into Cas9-overproducing plants. Here, we describe how to induce heritable targeted mutations in a non-model plant, Nicotiana attenuata, using VIGE system. This method will be applied for manipulating the target genes in any plants that scientists are interested in.
Assuntos
Edição de Genes , Nicotiana , Edição de Genes/métodos , Nicotiana/genética , Sistemas CRISPR-Cas/genética , Plantas/genética , Genoma de Planta , Plantas Geneticamente Modificadas/genéticaRESUMO
The adolescent social experience is essential for the maturation of the prefrontal cortex in mammalian species. However, it still needs to be determined which cortical circuits mature with such experience and how it shapes adult social behaviors in a sex-specific manner. Here, we examined social-approaching behaviors in male and female mice after postweaning social isolation (PWSI), which deprives social experience during adolescence. We found that the PWSI, particularly isolation during late adolescence, caused an abnormal increase in social approaches (hypersociability) only in female mice. We further found that the PWSI female mice showed reduced parvalbumin (PV) expression in the left orbitofrontal cortex (OFCL). When we measured neural activity in the female OFCL, a substantial number of neurons showed higher activity when mice sniffed other mice (social sniffing) than when they sniffed an object (object sniffing). Interestingly, the PWSI significantly reduced both the number of activated neurons and the activity level during social sniffing in female mice. Similarly, the CRISPR/Cas9-mediated knockdown of PV in the OFCL during late adolescence enhanced sociability and reduced the social sniffing-induced activity in adult female mice via decreased excitability of PV+ neurons and reduced synaptic inhibition in the OFCL Moreover, optogenetic activation of excitatory neurons or optogenetic inhibition of PV+ neurons in the OFCL enhanced sociability in female mice. Our data demonstrate that the adolescent social experience is critical for the maturation of PV+ inhibitory circuits in the OFCL; this maturation shapes female social behavior via enhancing social representation in the OFCL SIGNIFICANCE STATEMENT Adolescent social isolation often changes adult social behaviors in mammals. Yet, we do not fully understand the sex-specific effects of social isolation and the brain areas and circuits that mediate such changes. Here, we found that adolescent social isolation causes three abnormal phenotypes in female but not male mice: hypersociability, decreased PV+ neurons in the left orbitofrontal cortex (OFCL), and decreased socially evoked activity in the OFCL Moreover, parvalbumin (PV) deletion in the OFCL in vivo caused the same phenotypes in female mice by increasing excitation compared with inhibition within the OFCL Our data suggest that adolescent social experience is required for PV maturation in the OFCL, which is critical for evoking OFCL activity that shapes social behaviors in female mice.
Assuntos
Neurônios , Parvalbuminas , Masculino , Camundongos , Animais , Feminino , Parvalbuminas/metabolismo , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Comportamento Social , Isolamento Social , Interneurônios/fisiologia , MamíferosRESUMO
Plant cells in damaged tissue can be reprogrammed to acquire pluripotency and induce callus formation. However, in the aboveground organs of many species, somatic cells that are distal to the wound site become less sensitive to auxin-induced callus formation, suggesting the existence of repressive regulatory mechanisms that are largely unknown. Here we reveal that submergence-induced ethylene signals promote callus formation by releasing post-transcriptional silencing of auxin receptor transcripts in non-wounded regions. We determined that short-term submergence of intact seedlings induces auxin-mediated cell dedifferentiation across the entirety of Arabidopsis thaliana explants. The constitutive triple response 1-1 (ctr1-1) mutation induced callus formation in explants without submergence, suggesting that ethylene facilitates cell dedifferentiation. We show that ETHYLENE-INSENSITIVE 2 (EIN2) post-transcriptionally regulates the abundance of transcripts for auxin receptor genes by facilitating microRNA393 degradation. Submergence-induced calli in non-wounded regions were suitable for shoot regeneration, similar to those near the wound site. We also observed submergence-promoted callus formation in Chinese cabbage (Brassica rapa), indicating that this may be a conserved mechanism in other species. Our study identifies previously unknown regulatory mechanisms by which ethylene promotes cell dedifferentiation and provides a new approach for boosting callus induction efficiency in shoot explants.
Assuntos
Ácidos IndolacéticosRESUMO
Lemna perpusilla and Lemna minor are free-floating plants that often live in the same habitat. However, little is known about how they differ in response to herbivore attacks. In this study, we examined the species-specific resistance of two Lemna species to the duckweed weevil, Tanysphyrus lemnae. The female adults of T. lemnae preferred to lay eggs on L. perpusilla over L. minor. In addition, the larvae of T. lemnae performed better when fed on L. perpusilla than on L. minor. To understand the physiological basis of species-specific resistance in the two Lemna species, we measured the amounts of jasmonic acid (JA), phytosterols, and flavonoids. Attacks by duckweed weevils increased the levels of JA in the two Lemna species, but these levels did not differ significantly between the two species. Interestingly, the levels of flavones (isoorientin, vitexin, and isovitexin) in L. minor species were higher than those in L. perpusilla. The in vitro bioassay showed that three flavones significantly decreased the survival rate of duckweed weevil larvae. Although L. perpusilla was less resistant to duckweed weevil attack compared to L. minor, L. perpusilla grew faster than L. minor regardless of the duckweed weevil attack. These results suggest that these two Lemna species have different defense strategies against the duckweed weevil.
RESUMO
Pectobacterium brasiliense (P. brasiliense) is a necrotrophic bacterium that causes the soft rot disease in Brassica rapa. However, the mechanisms underlying plant immune responses against necrotrophic bacterial pathogens with a broad host range are still not well understood. Using a flg22-triggered seedling growth inhibition (SGI) assay with 455 Brassica rapa inbred lines, we selected six B. rapa flagellin-insensitive lines (Brfin2-7) and three B. rapa flagellin-sensitive lines (Brfs1-3). Brfin lines showed compromised flg22-induced immune responses (oxidative burst, mitogen-activated protein kinase (MAPK) activation, and seedling growth inhibition) compared to the control line R-o-18; nevertheless, they were resistant to P. brasiliense. To explain this, we analyzed the phytohormone content and found that most Brfin lines had higher P. brasiliense-induced jasmonic acid (JA) than Brfs lines. Moreover, MeJA pretreatment enhanced the resistance of B. rapa to P. brasiliense. To explain the correlation between the resistance of Brfin lines to P. brasiliense and activated JA signaling, we analyzed pathogen-induced glucosinolate (GS) content in B. rapa. Notably, in Brfin7, the neoglucobrassicin (NGBS) content among indole glucosinolates (IGS) was significantly higher than that in Brfs2 following P. brasiliense inoculation, and genes involved in IGSs biosynthesis were also highly expressed. Furthermore, almost all Brfin lines with high JA levels and resistance to P. brasiliense had higher P. brasiliense-induced NGBS levels than Brfs lines. Thus, our results show that activated JA-mediated signaling attenuates flg22-triggered immunity but enhances resistance to P. brasiliense by inducing indole glucosinolate biosynthesis in Brassica rapa. This study provides novel insights into the role of JA-mediated defense against necrotrophic bacterial pathogens within a broad host range.
RESUMO
Potato (Solanum tuberosum L.) cultivation is threatened by various environmental stresses, especially disease. Genome editing technologies are effective tools for generating pathogen-resistant potatoes. Here, we established an efficient RNP-mediated CRISPR/Cas9 genome editing protocol in potato to develop Phytophthora infestans resistant mutants by targeting the susceptibility gene, Signal Responsive 4 (SR4), in protoplasts. Mutations in StSR4 were efficiently introduced into the regenerated potato plants, with a maximum efficiency of 34%. High co-expression of StEDS1 and StPAD4 in stsr4 mutants induced the accumulation of salicylic acid (SA), and enhanced the expression of the pathogen resistance marker StPR1. In addition, increased SA content in the stsr4 mutant enhanced its resistance to P. infestans more than that in wild type. However, the growth of stsr4_3-19 and stsr4_3-698 mutants with significantly high SA was strongly inhibited, and a dwarf phenotype was induced. Therefore, it is important to adequate SA accumulation in order to overcome StSR4 editing-triggered growth inhibition and take full advantages of the improved pathogen resistance of stsr4 mutants. This RNP-mediated CRISPR/Cas9-based potato genome editing protocol will accelerate the development of pathogen-resistant Solanaceae crops via molecular breeding.
RESUMO
The timely removal of end-of-purpose flowering organs is as essential for reproduction and plant survival as timely flowering. Despite much progress in understanding the molecular mechanisms of floral organ abscission, little is known about how various environmental factors are integrated into developmental programmes that determine the timing of abscission. Here, we investigated whether reactive oxygen species (ROS), mediators of various stress-related signalling pathways, are involved in determining the timing of abscission and, if so, how they are integrated with the developmental pathway in Arabidopsis thaliana. MSD2, encoding a secretory manganese superoxide dismutase, was preferentially expressed in the abscission zone of flowers, and floral organ abscission was accelerated by the accumulation of ROS in msd2 mutants. The expression of the genes encoding the receptor-like kinase HAESA (HAE) and its cognate peptide ligand INFLORESCENCE DEFICIENT IN ABSCISSION (IDA), the key signalling components of abscission, was accelerated in msd2 mutants, suggesting that MSD2 acts upstream of IDA-HAE. Further transcriptome and pharmacological analyses revealed that abscisic acid and nitric oxide facilitate abscission by regulating the expression of IDA and HAE during MSD2-mediated signalling. These results suggest that MSD2-dependent ROS metabolism is an important regulatory point integrating environmental stimuli into the developmental programme leading to abscission.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Espécies Reativas de Oxigênio/metabolismo , ReproduçãoRESUMO
Effects of environmental change on plants can differ due to sequential changes in their life-history strategies (i.e., ontogenetic variations). The fitness of herbivorous insects by physiological changes of the host plant could be affected depending on their diet breadth. However, little is known regarding the combinational effects of plant ontogeny and climate change on plant-herbivore interactions. This study examined the plant ontogeny-dependent effects of climate change on the interaction between a host plant (Aristolochia contorta), its specialist herbivore (Sericinus montela), and a generalist herbivore (Spodoptera exigua). Plants were grown under a factorial design of two distinct CO2 concentrations (ambient, 400 ppm; elevated, 560 ppm) and two watering frequencies (control, once a week; increased, twice a week). Plant ontogeny ameliorated the effects of climate change by altering its defensive traits, where nutrient-related factors were cumulatively affected by climate change. Herbivore performance was assessed at three different plant ontogenetic stages (1st-year juvenile, 1st-year senescence, and 2nd-year juvenile). Elevated CO2 levels reduced the growth and survival of the specialist herbivore, whereas increased watering frequency partially alleviated this reduced performance. Generalist herbivore performance slightly increased under elevated CO2 levels with progressing ontogenetic stages. The effects of climate change, both elevated CO2 and increased watering frequency were weaker in 2nd-year juveniles than in 1st-year juveniles. Elevated CO2 levels detrimentally affected the nutritional quality of A. contorta leaves. The effects of climate change on both specialist and generalist herbivore performance differed as plant ontogenetic stage proceeded. Increased growth rates and survival of the generalist herbivore at the latter ontogenetic stage might negatively affect the population dynamics of a specialist herbivore. This study suggests that biases are possible when the plant-herbivore interaction under a changing environment is predicted from a singular plant ontogenetic stage.