scholarly journals Transcriptomic and genetic approaches reveal an essential role of the NAC transcription factor SlNAP1 in the growth and defense response of tomato

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiao Wang ◽  
Chenfei Zheng ◽  
Xiangqi Shao ◽  
Zhangjian Hu ◽  
Jianxin Li ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Defense Response ◽  
Global Climate ◽  
Plant Responses ◽  
Multiple Stresses ◽  
Bacterial Diseases ◽  
Bacterial Wilt Disease ◽  
Transgenic Lines ◽  
Breeding Target

AbstractWith global climate change, plants are frequently being exposed to various stresses, such as pathogen attack, drought, and extreme temperatures. Transcription factors (TFs) play crucial roles in numerous plant biological processes; however, the functions of many tomato (Solanum lycopersicum L.) TFs that regulate plant responses to multiple stresses are largely unknown. Here, using an RNA-seq approach, we identified SlNAP1, a NAC TF-encoding gene, which was strongly induced by various stresses. By generating SlNAP1 transgenic lines and evaluating their responses to biotic and abiotic stresses in tomato, we found that SlNAP1-overexpressing plants showed significantly enhanced defense against two widespread bacterial diseases, leaf speck disease, caused by Pseudomonas syringae pv. tomato (Pst) DC3000, and root-borne bacterial wilt disease, caused by Ralstonia solanacearum. In addition, SlNAP1 overexpression dramatically improved drought tolerance in tomato. Although the SlNAP1-overexpressing plants were shorter than the wild-type plants during the early vegetative stage, eventually, their fruit yield increased by 10.7%. Analysis of different hormone contents revealed a reduced level of physiologically active gibberellins (GAs) and an increased level of salicylic acid (SA) and abscisic acid (ABA) in the SlNAP1-overexpressing plants. Moreover, EMSAs and ChIP-qPCR assays showed that SlNAP1 directly activated the transcription of multiple genes involved in GA deactivation and both SA and ABA biosynthesis. Our findings reveal that SlNAP1 is a positive regulator of the tomato defense response against multiple stresses and thus may be a potential breeding target for improving crop yield and stress resistance.

scholarly journals Heterologous Expression of the Grapevine JAZ7 Gene in Arabidopsis Confers Enhanced Resistance to Powdery Mildew but Not to Botrytis cinerea

2018 ◽  
Vol 19 (12) ◽  
pp. 3889 ◽  
Author(s):  
Muhammad Hanif ◽  
Mati Rahman ◽  
Min Gao ◽  
Jinhua Yang ◽  
Bilal Ahmad ◽  
...  
Keyword(s):  
Heterologous Expression ◽  
Botrytis Cinerea ◽  
Pseudomonas Syringae ◽  
Pathogen Resistance ◽  
Resistance Function ◽  
Wild Grapevine ◽  
Golovinomyces Cichoracearum ◽  
Transgenic Lines ◽  
Inducible Genes

Jasmonate ZIM-domain (JAZ) family proteins comprise a class of transcriptional repressors that silence jasmonate-inducible genes. Although a considerable amount of research has been carried out on this gene family, there is still very little information available on the role of specific JAZ gene members in multiple pathogen resistance, especially in non-model species. In this study, we investigated the potential resistance function of the VqJAZ7 gene from a disease-resistant wild grapevine, Vitis quinquangularis cv. “Shang-24”, through heterologous expression in Arabidopsis thaliana. VqJAZ7-expressing transgenic Arabidopsis were challenged with three pathogens: the biotrophic fungus Golovinomyces cichoracearum, necrotrophic fungus Botrytis cinerea, and semi-biotrophic bacteria Pseudomonas syringae pv. tomato DC3000. We found that plants expressing VqJAZ7 showed greatly reduced disease symptoms for G. cichoracearum, but not for B. cinerea or P. syringae. In response to G cichoracearum infection, VqJAZ7-expressing transgenic lines exhibited markedly higher levels of cell death, superoxide anions (O2¯, and H2O2 accumulation, relative to nontransgenic control plants. Moreover, we also tested the relative expression of defense-related genes to comprehend the possible induced pathways. Taken together, our results suggest that VqJAZ7 in grapevine participates in molecular pathways of resistance to G. cichoracearum, but not to B. cinerea or P. syringae.

Quantitative proteomics reveals a role of JAZ7 in plant defense response to Pseudomonas syringae DC3000

2018 ◽  
Vol 175 ◽  
pp. 114-126 ◽  
Author(s):  
Tong Zhang ◽  
Li Meng ◽  
Wenwen Kong ◽  
Zepeng Yin ◽  
Yang Wang ◽  
...  
Keyword(s):  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Defense Response ◽  
Quantitative Proteomics ◽  
Plant Defense Response

scholarly journals Citrus reticulata CrRAP2.2 Transcriptional Factor Shares Similar Functions to the Arabidopsis Homolog and Increases Resistance to Xylella fastidiosa

2020 ◽  
Vol 33 (3) ◽  
pp. 519-527
Author(s):  
Willian Pereira ◽  
Marco Takita ◽  
Maeli Melotto ◽  
Alessandra de Souza
Keyword(s):  
Defense Response ◽  
Xylella Fastidiosa ◽  
Transcriptional Factor ◽  
Sources Of Resistance ◽  
Transgenic Lines ◽  
Global Threat ◽  
Arabidopsis Homolog ◽  
Factor Shares ◽  
Made In

Xylella fastidiosa is a worldwide multihost pathogen that causes diseases in different crops. It is considered a new global threat and substantial efforts have been made in order to identify sources of resistance. Indeed, many genes have been associated with resistance to X. fastidiosa, but without functional validation. Here, we describe a C. reticulata gene homologous to the transcriptional factor RAP2.2 from Arabidopsis thaliana that increases resistance to citrus variegated chlorosis (CVC). This gene was previously detected in C. reticulata challenged with X. fastidiosa. Bioinformatics analysis together with subcellular localization and auto-activation assays indicated that RAP2.2 from C. reticulata (CrRAP2.2) is a transcriptional factor orthologous to AtRAP2.2. Thus, we used A. thaliana as a model host to evaluate the functional role of CrRAP2.2 in X. fastidiosa resistance. The inoculation of X. fastidiosa in the A. thaliana rap2.2 mutant resulted in a larger bacterial population, which was complemented by CrRAP2.2. In addition, symptoms of anthocyanin accumulation were higher in the mutant, whose phenotype was restored by CrRAP2.2, indicating that they have conserved functions in plant defense response. We therefore transformed C. sinensis with CrRAP2.2 and verified a positive correlation between CVC resistance and gene expression in transgenic lines. This is the first study using A. thaliana as model host that characterizes the function of a gene related to X. fastidiosa defense response and its application in genetic engineering to obtain citrus resistance to CVC.

Role of potassium transporter KUP8 in plant responses to heavy metals

2021 ◽  
Author(s):  
María Sanz‐Fernández ◽  
Alejandro Rodríguez‐González ◽  
Luisa M. Sandalio ◽  
María C. Romero‐Puertas
Keyword(s):  
Heavy Metals ◽  
Plant Responses ◽  
Potassium Transporter

Ammonium application mitigates the effects of elevated carbon dioxide on the carbon/nitrogen balance of Phoebe bournei seedlings

2021 ◽  
Author(s):  
Xiao Wang ◽  
Xiaoli Wei ◽  
Gaoyin Wu ◽  
Shengqun Chen
Keyword(s):  
Carbon Dioxide ◽  
Enzyme Activities ◽  
Atmospheric Carbon Dioxide ◽  
Global Climate ◽  
Co2 Concentration ◽  
Rubisco Activase ◽  
Plant Responses ◽  
N Metabolism ◽  
C And N ◽  
Phoebe Bournei

Abstract The study of plant responses to increases in atmospheric carbon dioxide (CO2) concentration is crucial to understand and to predict the effect of future global climate change on plant adaptation and evolution. Increasing amount of nitrogen (N) can promote the positive effect of CO2, while how N forms would modify the degree of CO2 effect is rarely studied. The aim of this study was to determine whether the amount and form of nitrogen (N) could mitigate the effects of elevated CO2 (eCO2) on enzyme activities related to carbon (C) and N metabolism, the C/N ratio, and growth of Phoebe bournei (Hemsl.) Y.C. Yang. One-year-old P. bournei seedlings were grown in an open-top air chamber under either an ambient CO2 (aCO2) (350 ± 70 μmol•mol−1) or an eCO2 (700 ± 10 μmol•mol−1) concentration and cultivated in soil treated with either moderate (0.8 g per seedling) or high applications (1.2 g per seedling) of nitrate or ammonium. In seedlings treated with a moderate level of nitrate, the activities of key enzymes involved in C and N metabolism (i.e., Rubisco, Rubisco activase and glutamine synthetase) were lower under eCO2 than under aCO2. By contrast, key enzyme activities (except GS) in seedlings treated with high nitrate or ammonium were not significantly different between aCO2 and eCO2 or higher under eCO2 than under aCO2. The C/N ratio of seedlings treated with moderate or high nitrate under eCO2was significantly changed compared with the seedlings grown under aCO2, whereas the C/N ratio of seedlings treated with ammonium was not significantly different between aCO2 and eCO2. Therefore, under eCO2, application of ammonium can be beneficial C and N metabolism and mitigate effects on the C/N ratio.

scholarly journals Susceptibility of Midge and Mosquito Vectors to SARS-CoV-2

2021 ◽  
Author(s):  
Velmurugan Balaraman ◽  
Barbara S Drolet ◽  
Natasha N Gaudreault ◽  
William C Wilson ◽  
Jeana Owens ◽  
...  
Keyword(s):  
Cell Lines ◽  
Potential Role ◽  
Animal Origin ◽  
Culex Tarsalis ◽  
Biting Midges ◽  
Bacterial Diseases ◽  
Culicoides Sonorensis ◽  
Insect Cell Lines ◽  
Intrathoracic Inoculation

Abstract SARS-CoV-2 is a recently emerged, highly contagious virus and the cause of the current COVID-19 pandemic. It is a zoonotic virus, although its animal origin is not clear yet. Person-to-person transmission occurs by inhalation of infected droplets and aerosols, or by direct contact with contaminated fomites. Arthropods transmit numerous viral, parasitic, and bacterial diseases; however, the potential role of arthropods in SARS-CoV-2 transmission is not fully understood. Thus far, a few studies have demonstrated that SARS-CoV-2 replication is not supported in cells from certain insect species nor in certain species of mosquitoes after intrathoracic inoculation. In this study, we expanded the work of SARS-CoV-2 susceptibility to biting insects after ingesting a SARS-CoV-2-infected bloodmeal. Species tested included Culicoides sonorensis (Wirth & Jones) (Diptera: Ceratopogonidae) biting midges, as well as Culex tarsalis (Coquillett) and Culex quinquefasciatus (Say) mosquitoes (Diptera: Culicidae), all known biological vectors for numerous RNA viruses. Arthropods were allowed to feed on SARS-CoV-2-spiked blood and at a time point postinfection analyzed for the presence of viral RNA and infectious virus. Additionally, cell lines derived from C. sonorensis (W8a), Aedes aegypti (Linnaeus) (Diptera: Culicidae) (C6/36), Cx. quinquefasciatus (HSU), and Cx. tarsalis (CxTrR2) were tested for SARS-CoV-2 susceptibility. Our results indicate that none of the biting insects, nor the insect cell lines evaluated support SARS-CoV-2 replication, suggesting that these species are unable to be biological vectors of SARS-CoV-2.

scholarly journals Ralstonia solanacearum Needs Motility for Invasive Virulence on Tomato

2001 ◽  
Vol 183 (12) ◽  
pp. 3597-3605 ◽  
Author(s):  
Julie Tans-Kersten ◽  
Huayu Huang ◽  
Caitilyn Allen
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Soft Agar ◽  
Cell Protein ◽  
In Planta ◽  
Tomato Plants ◽  
Bacterial Wilt Disease ◽  
Virulence Assay ◽  
Flagellar Filament

ABSTRACT Ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. By examining bacteria from the xylem vessels of infected plants, we found thatR. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. To determine the role of pathogen motility in this disease, we cloned, characterized, and mutated two genes in the R. solanacearum flagellar biosynthetic pathway. The genes for flagellin, the subunit of the flagellar filament (fliC), and for the flagellar motor switch protein (fliM) were isolated based on their resemblance to these proteins in other bacteria. As is typical for flagellins, the predicted FliC protein had well-conserved N- and C-terminal regions, separated by a divergent central domain. The predicted R. solanacearum FliM closely resembled motor switch proteins from other proteobacteria. Chromosomal mutants lackingfliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphAcassette was used to make a nonpolar fliM mutation. Both mutants were completely nonmotile on soft agar plates, in minimal broth, and in tomato plants. The fliC mutant lacked flagella altogether; moreover, sheared-cell protein preparations from the fliC mutant lacked a 30-kDa band corresponding to flagellin. The fliM mutant was usually aflagellate, but about 10% of cells had abnormal truncated flagella. In a biologically representative soil-soak inoculation virulence assay, both nonmotile mutants were significantly reduced in the ability to cause disease on tomato plants. However, the fliC mutant had wild-type virulence when it was inoculated directly onto cut tomato petioles, an inoculation method that did not require bacteria to enter the intact host from the soil. These results suggest that swimming motility makes its most important contribution to bacterial wilt virulence in the early stages of host plant invasion and colonization.

Over-expression of the rice OsAMT1-1 gene increases ammonium uptake and content, but impairs growth and development of plants under high ammonium nutrition

2006 ◽  
Vol 33 (2) ◽  
pp. 153 ◽  
Author(s):  
Mohammad S. Hoque ◽  
Josette Masle ◽  
Michael K. Udvardi ◽  
Peter R. Ryan ◽  
Narayana M. Upadhyaya
Keyword(s):  
Transgenic Plants ◽  
Ammonium Assimilation ◽  
Ammonium Transporter ◽  
Ammonium Uptake ◽  
Vegetative Stage ◽  
Over Expression ◽  
Transgenic Lines ◽  
Ammonium Nutrition ◽  
Maize Ubiquitin Promoter

A transgenic approach was undertaken to investigate the role of a rice ammonium transporter (OsAMT1-1) in ammonium uptake and consequent ammonium assimilation under different nitrogen regimes. Transgenic lines overexpressing OsAMT1-1 were produced by Agrobacterium-mediated transformation of two rice cultivars, Taipei 309 and Jarrah, with an OsAMT1-1 cDNA gene construct driven by the maize ubiquitin promoter. Transcript levels of OsAMT1-1 in both Taipei 309 and Jarrah transgenic lines correlated positively with transgene copy number. Shoot and root biomass of some transgenic lines decreased during seedling and early vegetative stage compared to the wild type, especially when grown under high (2 mm) ammonium nutrition. Transgenic plants, particularly those of cv. Jarrah recovered in the mid-vegetative stage under high ammonium nutrition. Roots of the transgenic plants showed increased ammonium uptake and ammonium content. We conclude that the decreased biomass of the transgenic lines at early stages of growth might be caused by the accumulation of ammonium in the roots owing to the inability of ammonium assimilation to match the greater ammonium uptake.

Decomposing the time-mean Atlantic Meridional Overturning Circulation and its variability with latitude.

2021 ◽  
Author(s):  
Tomas Jonathan ◽  
Mike Bell ◽  
Helen Johnson ◽  
David Marshall
Keyword(s):  
Global Climate ◽  
Dominant Role ◽  
Meridional Overturning Circulation ◽  
Western Boundary ◽  
Relative Role ◽  
Overturning Circulation ◽  
Near Surface ◽  
Boundary Density ◽  
Meridional Overturning

<p>The Atlantic Meridional Overturning Circulations (AMOC) is crucial to our global climate, transporting heat and nutrients around the globe. Detecting  potential climate change signals first requires a careful characterisation of inherent natural AMOC variability. Using a hierarchy of global coupled model  control runs (HadGEM-GC3.1, HighResMIP) we decompose the overturning circulation as the sum of (near surface) Ekman, (depth-dependent) bottom velocity, eastern and western boundary density components, as a function of latitude. This decomposition proves a useful low-dimensional characterisation of the full 3-D overturning circulation. In particular, the decomposition provides a means to investigate and quantify the constraints which boundary information imposes on the overturning, and the relative role of eastern versus western contributions on different timescales. </p><p>The basin-wide time-mean contribution of each boundary component to the expected streamfunction is investigated as a function of depth, latitude and spatial resolution. Regression modelling supplemented by Correlation Adjusted coRrelation (CAR) score diagnostics provide a natural ranking of the contributions of the various components in explaining the variability of the total streamfunction. Results reveal the dominant role of the bottom component, western boundary and Ekman components at short time-scales, and of boundary density components at decadal and longer timescales.</p>

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