scholarly journals Natural variation in a short region of the Acidovorax citrulli type III-secreted effector AopW1 is associated with differences in cytotoxicity

2021 ◽  
Author(s):  
IRENE JIMENEZ-GUERRERO ◽  
MONICA SONAWANE ◽  
NOAM ECKSHTAIN-LEVI ◽  
GUSTAVO M. DA SILVA ◽  
FRANCISCO PEREZ-MONTANO ◽  
...  
Keyword(s):  
Amino Acid ◽  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Variable Region ◽  
Callose Deposition ◽  
Type Iii ◽  
Acidovorax Citrulli ◽  
Group I ◽  
Group Ii

Bacterial fruit blotch (BFB) is a serious disease of melon and watermelon caused by the Gram-negative bacterium Acidovorax citrulli. The strains of the pathogen can be divided into two major genetic groups, I and II. While group I strains are strongly associated with melon, group II strains are more aggressive on watermelon. Like many pathogenic bacteria, A. citrulli secretes a variety of protein effectors to the host cell via the type III secretion system. In the present study, we characterized AopW1, an A. citrulli type III-secreted effector that shares similarity with the actin cytoskeleton-disrupting effector HopW1 of Pseudomonas syringae and with effectors from other plant-pathogenic bacterial species. aopW1 is present in group I and II strains, encoding products of 485 amino acids. Although highly conserved in most of the sequence, AopW1 has a highly variable region (HVR) within amino acid positions 147 to 192, including 14 amino acid differences between groups. Here we show that group I AopW1 is more toxic to yeast and plant cells than group II AopW1, having a stronger actin filament disruption activity, and increased ability to reduce plant callose deposition. We demonstrate the role of some of these 14 amino acid positions in determining the phenotypic differences between the two versions of the effector. Moreover, cellular analyses revealed that in addition to the interaction with actin filaments, AopW1 is localized to the endoplasmic reticulum, chloroplasts, and early and recycling plant endosomes, with differences observed between the two AopW1 versions. Finally, we show that overexpression of the endosome-associated protein EHD1 that increases cellular recycling, attenuates the toxic effects exerted by AopW1 and increases defence responses. This study provides insights into the HopW1 family of bacterial effectors and their interactions with the plant cell and provides first evidence on the involvement of EHD1 in response to biotic stress.

scholarly journals Comparative Analysis of Type III Secreted Effector Genes Reflects Divergence of Acidovorax citrulli Strains into Three Distinct Lineages

2014 ◽  
Vol 104 (11) ◽  
pp. 1152-1162 ◽  
Author(s):  
Noam Eckshtain-Levi ◽  
Tamar Munitz ◽  
Marija Živanović ◽  
Sy M. Traore ◽  
Cathrin Spröer ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Type Iii Secretion ◽  
Pathogenic Bacteria ◽  
Citrullus Lanatus ◽  
Housekeeping Genes ◽  
Type Iii ◽  
Effector Genes ◽  
Acidovorax Citrulli ◽  
Group I ◽  
Group Ii

Acidovorax citrulli causes bacterial fruit blotch of cucurbits, a serious economic threat to watermelon (Citrullus lanatus) and melon (Cucumis melo) production worldwide. Based on genetic and biochemical traits, A. citrulli strains have been divided into two distinct groups: group I strains have been mainly isolated from various non-watermelon hosts, while group II strains have been generally isolated from and are highly virulent on watermelon. The pathogen depends on a functional type III secretion system for pathogenicity. Annotation of the genome of the group II strain AAC00-1 revealed 11 genes encoding putative type III secreted (T3S) effectors. Due to the crucial role of type III secretion for A. citrulli pathogenicity, we hypothesized that group I and II strains differ in their T3S effector repertoire. Comparative analysis of the 11 effector genes from a collection of 22 A. citrulli strains confirmed this hypothesis. Moreover, this analysis led to the identification of a third A. citrulli group, which was supported by DNA:DNA hybridization, DNA fingerprinting, multilocus sequence analysis of conserved genes, and virulence assays. The effector genes assessed in this study are homologous to effectors from other plant-pathogenic bacteria, mainly belonging to Xanthomonas spp. and Ralstonia solanacearum. Analyses of the effective number of codons and gas chromatography content of effector genes relative to a representative set of housekeeping genes support the idea that these effector genes were acquired by lateral gene transfer. Further investigation is required to identify new T3S effectors of A. citrulli and to determine their contribution to virulence and host preferential association.

scholarly journals Characterization of the hrpC and hrpRSOperons of Pseudomonas syringae Pathovars Syringae, Tomato, and Glycinea and Analysis of the Ability of hrpF,hrpG, hrcC, hrpT, and hrpVMutants To Elicit the Hypersensitive Response and Disease in Plants

1998 ◽  
Vol 180 (17) ◽  
pp. 4523-4531 ◽  
Author(s):  
Wen-Ling Deng ◽  
Gail Preston ◽  
Alan Collmer ◽  
Chun-Jung Chang ◽  
Hsiou-Chen Huang
Keyword(s):  
Amino Acid ◽  
Outer Membrane ◽  
Pseudomonas Syringae ◽  
Hypersensitive Response ◽  
Amino Acid Identity ◽  
The Other ◽  
Wild Type ◽  
Acid Identity ◽  
Type Iii ◽  
Group I

The species Pseudomonas syringae encompasses plant pathogens with differing host specificities and corresponding pathovar designations. P. syringae requires the Hrp (type III protein secretion) system, encoded by a 25-kb cluster ofhrp and hrc genes, in order to elicit the hypersensitive response (HR) in nonhosts or to be pathogenic in hosts. DNA sequence analysis of the hrpC and hrpRSoperons of P. syringae pv. syringae 61 (brown spot of beans), P. syringae pv. glycinea U1 (bacterial blight of soybeans), and P. syringae pv. tomato DC3000 (bacterial speck of tomatos) revealed that the 13 genes comprising the right half of the hrp cluster (including those in the previously sequenced hrpZ operon) are conserved and identically arranged. The hrpC operon is comprised of hrpF,hrpG, hrcC, hrpT, and hrpV. hrcC encodes a putative outer membrane protein that is conserved in all type III secretion systems. The other four genes appear to be characteristic of group I Hrp systems, such as those possessed byP. syringae and Erwinia amylovora. The predicted products of these four genes in P. syringae pv. syringae 61 are HrpF (8 kDa), HrpG (15.4 kDa), HrpT (7.5 kDa), and HrpV (13.4 kDa). HrpT is a putative outer membrane lipoprotein. HrpF, HrpG, and HrpV are all hydrophilic proteins lacking N-terminal signal peptides. The HrpG, HrcC, HrpT, and HrpV proteins of P. syringae pathovars syringae and tomato (the two most divergent pathovars) had at least 76% amino acid identity with each other, whereas the HrpF proteins of these two pathovars had only 36% amino acid identity. The HrpF proteins of P. syringae pathovars syringae and glycinea also showed significant similarity to the HrpA pilin protein of P. syringae pathovar tomato. Functionally nonpolar mutations were introduced into each of the genes in thehrpC operon of P. syringae pv. syringae 61 by insertion of an nptII cartridge lacking a transcription terminator. The mutants were assayed for their ability to elicit the HR in nonhost tobacco leaves or to multiply and cause disease in host bean leaves. Mutations in hrpF, hrcC, andhrpT abolished or greatly reduced the ability of P. syringae pv. syringae 61 to elicit the HR in tobacco. ThehrpG mutant had only weakly reduced HR activity, and the activity of the hrpV mutant was indistinguishable from that of the wild type. Each of the mutations could be complemented, but surprisingly, the hrpV subclone caused a reduction in the HR elicitation ability of the ΔhrpV::nptIImutant. The hrpF and hrcC mutants caused no disease in beans, whereas the hrpG, hrpT, and hrpV mutants had reduced virulence. Similarly, thehrcC mutant grew little in beans, whereas the other mutants grew to intermediate levels in comparison with the wild type. These results indicate that HrpC and HrpF have essential functions in the Hrp system, that HrpG and HrpT contribute quantitatively but are not essential, and that HrpV is a candidate negative regulator of the Hrp system.

scholarly journals Discovery and Characterization of Low-Molecular Weight Inhibitors of Erwinia tracheiphila

2020 ◽  
Vol 110 (5) ◽  
pp. 989-998
Author(s):  
Cláudio M. Vrisman ◽  
Loïc Deblais ◽  
Yosra A. Helmy ◽  
Reed Johnson ◽  
Gireesh Rajashekara ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
High Throughput Screening ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Bacillus Species ◽  
Erwinia Tracheiphila ◽  
Static Activity ◽  
Low Toxicity

Plant pathogenic bacteria in the genus Erwinia cause economically important diseases, including bacterial wilt of cucurbits caused by Erwinia tracheiphila. Conventional bactericides are insufficient to control this disease. Using high-throughput screening, 464 small molecules (SMs) with either cidal or static activity at 100 µM against a cucumber strain of E. tracheiphila were identified. Among them, 20 SMs (SM1 to SM20), composed of nine distinct chemical moiety structures, were cidal to multiple E. tracheiphila strains at 100 µM. These lead SMs had low toxicity to human cells and honey bees at 100 µM. No phytotoxicity was observed on melon plants at 100 µM, except when SM12 was either mixed with Silwet L-77 and foliar sprayed or when delivered through the roots. Lead SMs did not inhibit the growth of beneficial Pseudomonas and Enterobacter species but inhibited the growth of Bacillus species. Nineteen SMs were cidal to Xanthomonas cucurbitae and showed >50% growth inhibition against Pseudomonas syringae pv. lachrymans. In addition, 19 SMs were cidal or static against Erwinia amylovora in vitro. Five SMs demonstrated potential to suppress E. tracheiphila when foliar sprayed on melon plants at 2× the minimum bactericidal concentration. Thirteen SMs reduced Et load in melon plants when delivered via roots. Temperature and light did not affect the activity of SMs. In vitro cidal activity was observed after 3 to 10 h of exposure to these five SMs. Here, we report 19 SMs that provide chemical scaffolds for future development of bactericides against plant pathogenic bacterial species.

Effect of amino acid infusion on renal hemodynamics in humans: a dose-response study

1994 ◽  
Vol 267 (5) ◽  
pp. F703-F708 ◽  
Author(s):  
M. Giordano ◽  
P. Castellino ◽  
E. L. McConnell ◽  
R. A. DeFronzo
Keyword(s):  
Amino Acid ◽  
Dose Response ◽  
Renal Hemodynamics ◽  
Group Iv ◽  
Group V ◽  
Group Iii ◽  
Amino Acid Infusion ◽  
Group I ◽  
Basal Plasma ◽  
Group Ii

We evaluated the dose-response relationship between the plasma amino acid (AA) concentration and renal hemodynamics in eight normal subjects. After an overnight fast, a balanced 10% AA solution was infused for 180 min at five separate infusion rates: 0.5 (group I), 1.0 (group II), 2.0 (group III), 4.0 (group IV), and 6.0 (group V) ml.kg-1.min-1 on separate days. Basal plasma AA concentration was 1.87 +/- 0.1 mmol/l and increased to 2.26 +/- 0.1 (group I), 2.66 +/- 0.2 (group II), 3.79 +/- 0.5 (group III), 5.81 +/- 0.4 (group IV), and 7.41 +/- 0.4 mmol/l (group V). Basal glomerular filtration rate (GFR) and renal plasma flow (RPF) averaged 95 +/- 4 and 476 +/- 29 ml.1.73 m-2.min-1, respectively, and rose to 98 +/- 5 and 506 +/- 40 (group I) [P = not significant (NS)], 102 +/- 3 and 533 +/- 30 (group II) (P < 0.05 vs. basal), 110 +/- 4 and 567 +/- 29 (group III), 115 +/- 7 and 610 +/- 55 (group IV), and 117 +/- 7 and 614 +/- 66 ml.1.73 m-2.min-1 (group V) (P = NS vs. group IV). Basal plasma glucagon concentration averaged 68 +/- 10 pg/ml and increased to 74 +/- 10 (group I), 83 +/- 11 (group II) (P < 0.05 vs. basal), 100 +/- 14 (group III), 121 +/- 14 (group IV), and 229 +/- 35 pg/ml (group V) (P < 0.01 vs. basal). Increases in plasma growth hormone (GH) and insulin levels were observed only during groups IV and V.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Pathomechanism of Insulin Resistance in Men with Central Obesity: Correlation of GGT, GPx, hs-CRP and Plasma Total Cysteine

2013 ◽  
Vol 5 (2) ◽  
pp. 101 ◽  
Author(s):  
Ritawaty Ritawaty ◽  
Indriyanti Rafi Sukmawati ◽  
Ilhamjaya Patellongi ◽  
Ferry Sandra
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Amino Acid ◽  
Fatty Liver ◽  
Central Obesity ◽  
Group Iv ◽  
Group Iii ◽  
Group I ◽  
Group Ii ◽  
Hs Crp

BACKGROUND: Gamma glutamyltransferase (GGT) was reported recently to be associated with inflammation, oxidative stress and increased amino acid. However, role of GGT in insulin resistance pathomechanism is not exactly known. Therefore correlation of GGT with inflammation, oxidative stress and elevated amino acid, in men with central obesity need to be confirmed.METHODS: A cross-sectional study was designed. Men with central obesity were recruited and selected. Anthropometric parameters, creatinine, hs-CRP, fasting glucose, fasting insulin, glutathione peroxidase (GPx) activity, GGT, plasma total cysteine (tCys) and fatty liver were measured. Subjects were then divided in 4 groups based on waist circumference (WC) and fatty liver: Group I: WC ≤100 cm, without fatty liver; Group II: WC ≤100 cm, with fatty liver; Group III: WC >100 cm, without fatty liver; Group IV: WC >100 cm, with fatty liver. All biochemical characteristics in each group were then statistically analyzed.RESULTS: Seventy-two men with central obesity were selected. Numbers of subjects in each group were: Group I: n=33; Group II: n=5; Group III: n=17; Group IV: n=17. We found significant difference of HOMA-IR between Group I and IV, significant correlation between GGT and HOMAIR, and significant negative correlation between tCys with HOMA-IR in Group IV.CONCLUSION: GGT was significantly correlated with HOMA-IR in men with WC >100 cm and fatty liver. Further investigation with more subjects is necessary to determine clear GGT cut-off to distinguish subjects with fatty liver and insulin resistance.KEYWORDS: GGT, hs-CRP, GPx, tCys, HOMA-IR, insulin resistance

scholarly journals Identification of Novel Type III Secretion Effectors in Xanthomonas oryzae pv. oryzae

2009 ◽  
Vol 22 (1) ◽  
pp. 96-106 ◽  
Author(s):  
Ayako Furutani ◽  
Minako Takaoka ◽  
Harumi Sanada ◽  
Yukari Noguchi ◽  
Takashi Oku ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Type Iii Secretion ◽  
Pathogenic Bacteria ◽  
Regulatory Protein ◽  
Effector Proteins ◽  
Xanthomonas Oryzae ◽  
Dependent Manner ◽  
Plant Pathogenic Bacteria ◽  
Type Iii ◽  
Genes Encoding

Many gram-negative bacteria secrete so-called effector proteins via a type III secretion (T3S) system. Through genome screening for genes encoding potential T3S effectors, 60 candidates were selected from rice pathogen Xanthomonas oryzae pv. oryzae MAFF311018 using these criteria: i) homologs of known T3S effectors in plant-pathogenic bacteria, ii) genes with expression regulated by hrp regulatory protein HrpX, or iii) proteins with N-terminal amino acid patterns associated with T3S substrates of Pseudomonas syringae. Of effector candidates tested with the Bordetella pertussis calmodulin-dependent adenylate cyclase reporter for translocation into plant cells, 16 proteins were translocated in a T3S system-dependent manner. Of these 16 proteins, nine were homologs of known effectors in other plant-pathogenic bacteria and seven were not. Most of the effectors were widely conserved in Xanthomonas spp.; however, some were specific to X. oryzae. Interestingly, all these effectors were expressed in an HrpX-dependent manner, suggesting coregulation of effectors and the T3S system. In X. campestris pv. vesicatoria, HpaB and HpaC (HpaP in X. oryzae pv. oryzae) have a central role in recruiting T3S substrates to the secretion apparatus. Secretion of all but one effector was reduced in both HpaB– and HpaP– mutant strains, indicating that HpaB and HpaP are widely involved in efficient secretion of the effectors.

scholarly journals The Effect of Parenteral Infusion of Amino Acids in Burn Patient

2013 ◽  
Vol 24 (1) ◽  
pp. 12-15
Author(s):  
Kamrun Nahar ◽  
Zeba-un Naher ◽  
Matira Khanam ◽  
Shaheen Akhter ◽  
Tahmina Bashar ◽  
...  
Keyword(s):  
Amino Acid ◽  
Serum Albumin ◽  
Total Protein ◽  
Burn Injury ◽  
Burn Patients ◽  
Serum Total Protein ◽  
Female Ratio ◽  
Group I ◽  
The Mean ◽  
Group Ii

Adequate nutritional support may prevent weight loss  following severe burn injury. However, persistently low  levels of serum albumin, transferring and serum total  protein in burn patients have suggested that a protein  deficiency may continue to exist which is out of proportion  to energy requirements.  This interventional study cross sectional study was done in  the Department of Biochemistry, Bangabandhu Sheikh  Mujib Medical University (BSMMU), Dhaka, Bangladesh  during January 2008 to December 2008. A total of 40 acute  burn injury (within 24 hours of burn) patients of 20-45  years age with 15%-30% burn were selected for this study  as case. The study subjects were divided into two groups:  Group I represent superficial burn & Group II represents  deep burn.  The mean age of 28.35±6.81 years and 30.85±7.32 years in  group I and group II respectively. The number of male in  Group-I was 08 and Group-II was 08 and male female ratio  was 2:3. The mean serum total protein before infusion of  amino acid in Group-I was 55.31±3.58 g/L and in Group-II  was 52.01±2.26 g/L (p<0.001). The mean serum total  protein after infusion of amino acid in Group-I was  68.02±2.04 g/L and in Group-II was 61.86±2.49g/L  (p<0.001). The mean serum albumin before infusion of  amino acid in Group-I was 27.6±2.88 g/L and in Group-II  was 25.57±1.89 g/L (p<0.001). The mean serum albumin  after infusion of amino acid in Group-I was 22.29±3.50 g/L  and in Group-II was 19.83±2.86 g/L (p<0.001). In group-I,  serum total protein was increased by 22.98% after infusion  and in group-II, that was increased by 18.94% (p<0.01).  In group-I, serum albumin was decreased by 19.24% after  infusion and in group-II, that was decreased by 22.45%  (p<0.05). Serum total protein significantly increased after  infusion of amino acid but serum albumin significantly  decreased after infusion of amino acid. DOI: http://dx.doi.org/10.3329/medtoday.v24i1.14107 Medicine TODAY Vol.24(1) 2012 pp.12-15

scholarly journals Genome-Assisted Development of a Diagnostic Protocol for Distinguishing High Virulence Pseudomonas syringae pv. tomato Strains

Plant Disease ◽  
2015 ◽  
Vol 99 (4) ◽  
pp. 527-534 ◽  
Author(s):  
Lisa A. Jones ◽  
Surya Saha ◽  
Alan Collmer ◽  
Christine D. Smart ◽  
Magdalen Lindeberg
Keyword(s):  
New York ◽  
Pseudomonas Syringae ◽  
Genome Comparison ◽  
Type Iii Effectors ◽  
Type Iii ◽  
Host Interaction ◽  
Group I ◽  
Virulent Strains ◽  
High Virulence ◽  
Relationship Of

A severe outbreak of bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, occurred in central New York in 2009. Isolate 09150, collected from this outbreak and subsequently named NYS-T1, was found to be highly virulent on tomato. To better understand the relationship of 09150 to other P. syringae strains and develop a diagnostic assay for aggressive strains of this pathogen, the 09150 genome was sequenced. Genome comparison revealed it to be highly similar to a previously sequenced isolate, T1. Genetic factors linked to host interaction including type III effectors, toxin biosynthetic genes, and elicitors of host innate immunity were identified. Type III effector repertoires were compared with other strains in the high virulence T1-like subgroup and lower virulence DC3000/P. syringae pv. maculicola subgroup within P. syringae phylogenetic Group I. Primers for conventional PCR were developed using sequences for avrA, hopW, conserved in the former subgroup and hopN, present in the latter. These were tested on isolates in the two subgroups, other pseudomonads, and other bacterial pathogens of tomato. Primers developed for avaA and hopW were diagnostic for more virulent strains of P. syringae pv. tomato while primers for hopN were diagnostic for P. syringae pv. tomato DC3000 and related P. syringe pv. maculicola strains. Primers designed against hopR distinguished both of these P. syringae subgroups from other P. syringae strains.

scholarly journals Genetically Distinct Acidovorax citrulli Strains Display Cucurbit Fruit Preference Under Field Conditions

2020 ◽  
Vol 110 (5) ◽  
pp. 973-980 ◽  
Author(s):  
Mei Zhao ◽  
Bhabesh Dutta ◽  
Xuelin Luo ◽  
Saul Burdman ◽  
Ron Walcott
Keyword(s):  
Field Conditions ◽  
Distribution Data ◽  
Specific Pcr ◽  
Acidovorax Citrulli ◽  
Group I ◽  
Fruit Preference ◽  
Direct Data ◽  
Group Ii ◽  
Specific Pcr Assay ◽  
Field Plots

Strains of Acidovorax citrulli, the causal agent of bacterial fruit blotch (BFB) of cucurbits, can be assigned to two groups, I and II. The natural association of group I and II strains with different cucurbit species suggests host preference; however, there are no direct data to support this hypothesis under field conditions. Hence, the objective of this study was to assess differences in the prevalence of group I and II A. citrulli strains on cucurbit species in the field. From 2017 to 2019, we used group I and II strains to initiate BFB outbreaks in field plots planted with four cucurbit species. At different times, we collected symptomatic tissues and assayed them for group I and II strains using a group-specific PCR assay. Binary distribution data analysis revealed that the odds of melon, pumpkin, and squash foliage infection by group I strains were 21.7, 11.5, and 22.1 times greater, respectively, than the odds of watermelon foliage infection by the group I strain (P < 0.0001). More strikingly, the odds of melon fruit infection by the group I strain were 97.5 times greater than watermelon fruit infection by the same strain (P < 0.0001). Unexpectedly, some of the group II isolates recovered from the 2017 and 2019 studies were different from the group II strains used as inocula. Overall, data from these experiments confirm that A. citrulli strains exhibit a preference for watermelon and melon, which is more pronounced in fruit tissues.

Plasma glucose and insulin responses in growing rats fed a total parenteral nutrition diet either intravenously or intragastrically

1984 ◽  
Vol 62 (7) ◽  
pp. 775-780 ◽  
Author(s):  
Norman S. Track ◽  
Ernest Cutz ◽  
Barbara H. Witt
Keyword(s):  
Amino Acid ◽  
Parenteral Nutrition ◽  
Total Parenteral Nutrition ◽  
Plasma Glucose ◽  
Plasma Insulin ◽  
Glucose Levels ◽  
Group I ◽  
Plasma Insulin Levels ◽  
Group Ii ◽  
Insulin Responses

The effect of administering either intravenously (group I) or intragastrically (group II) a glucose – amino acid total parenteral nutrition diet over a 12-day period upon plasma glucose and insulin responses was examined in adolescent rats. Infusion of the 25% glucose – 12.2% amino acid diet at a rate of 300 kCal∙kg body weight−1∙24 h−1 supported normal weight gain over the 12-day study period in both intravenously (group I) and intragastrically (group II) alimented rats. Mean plasma glucose levels rose dramatically in both groups by the end of day 1; group I had significantly higher mean plasma insulin levels. By day 3, the group I mean plasma glucose value decreased significantly while the group II mean glucose value remained virtually unchanged. Mean plasma insulin values more than doubled in both groups with the group I level still remaining significantly above the group II level. At days 6 and 12, group I mean plasma glucose levels were significantly below group II while both groups had similar plasma insulin levels. Data from this 12-day intravenous–intragastric alimentation study reveals quite different metabolic responses compared with acute (120–180 min) studies of the enteroinsular axis.

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