scholarly journals Colonisation of Oncidium orchid roots by the endophyte Piriformospora indica restricts Erwinia chrysanthemi infection, stimulates accumulation of NBS-LRR resistance gene transcripts and represses their targeting micro-RNAs in leaves

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Wei Ye ◽  
Jinlan Jiang ◽  
Yuling Lin ◽  
Kai-Wun Yeh ◽  
Zhongxiong Lai ◽  
...  
Keyword(s):  
Root Colonization ◽  
Soft Rot ◽  
Piriformospora Indica ◽  
Erwinia Chrysanthemi ◽  
Disease Development ◽  
Bioinformatic Tools ◽  
Regulatory Circuit ◽  
Micro Rnas ◽  
Salicylic Acid Accumulation ◽  
Gene Transcripts

Abstract Background Erwinia chrysanthemi (Ec) is a destructive pathogen which causes soft-rot diseases in diverse plant species including orchids. We investigated whether colonization of Oncidium roots by the endophytic fungus Piriformospora indica (Pi) restricts Ec-induced disease development in leaves, and whether this might be related to the regulation of nucleotide binding site-leucine rich repeat (NBS-LRR) Resistance (R) genes. Results Root colonization of Oncidium stackings by Pi restricts progression of Ec-induced disease development in the leaves. Since Pi does not inhibit Ec growth on agar plates, we tested whether NBS-LRR R gene transcripts and the levels of their potential target miRNAs in Oncidium leaves might be regulated by Pi. Using bioinformatic tools, we first identified NBS-LRR R gene sequences from Oncidium, which are predicted to be targets of miRNAs. Among them, the expression of two R genes was repressed and the accumulation of several regulatory miRNA stimulated by Ec in the leaves of Oncidium plants. This correlated with the progression of disease development, jasmonic and salicylic acid accumulation, ethylene synthesis and H2O2 production after Ec infection of Oncidium leaves. Interestingly, root colonization by Pi restricted disease development in the leaves, and this was accompanied by higher expression levels of several defense-related R genes and lower expression level of their target miRNA. Conclusion Based on these data we propose that Pi controls the levels of NBS-LRR R mRNAs and their target miRNAs in leaves. This regulatory circuit correlates with the protection of Oncidium plants against Ec infection, and molecular and biochemical investigations will demonstrate in the future whether, and if so, to what extent these two observations are related to each other.

scholarly journals Complete Genome Sequence of Dickeya dadantii subsp. dieffenbachiae Strain S3-1, Isolated from a White-Flowered Calla Lily in Taiwan

2021 ◽  
Vol 10 (37) ◽  
Author(s):  
Yung-An Lee ◽  
Kuan-Pei Chen
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Soft Rot ◽  
Erwinia Chrysanthemi ◽  
Bacterial Soft Rot ◽  
Plant Host ◽  
Dickeya Dadantii ◽  
Content Type ◽  
Calla Lily

Erwinia chrysanthemi S3-1 is a bacterial soft rot pathogen of the white-flowered calla lily. The complete genome sequence of the strain was determined and used to reclassify the strain as Dickeya dadantii subsp. dieffenbachiae . The sequence will be useful to study plant host-driven speciation in strains of D. dadantii .

scholarly journals The Erwinia chrysanthemi 3937 PhoQ Sensor Kinase Regulates Several Virulence Determinants

2006 ◽  
Vol 188 (8) ◽  
pp. 3088-3098 ◽  
Author(s):  
Balakrishnan Venkatesh ◽  
Lavanya Babujee ◽  
Hui Liu ◽  
Pete Hedley ◽  
Takashi Fujikawa ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Regulatory System ◽  
Soft Rot ◽  
Erwinia Chrysanthemi ◽  
Pcr Analysis ◽  
Sensor Kinase ◽  
Virulence Determinants ◽  
Gene Encoding ◽  
Reverse Transcription Pcr ◽  
Two Component

ABSTRACT The PhoPQ two-component system regulates virulence factors in Erwinia chrysanthemi, a pectinolytic enterobacterium that causes soft rot in several plant species. We characterized the effect of a mutation in phoQ, the gene encoding the sensor kinase PhoQ of the PhoPQ two-component regulatory system, on the global transcriptional profile of E. chrysanthemi using cDNA microarrays and further confirmed our results by quantitative reverse transcription-PCR analysis. Our results indicate that a mutation in phoQ affects transcription of at least 40 genes, even in the absence of inducing conditions. Enhanced expression of several genes involved in iron metabolism was observed in the mutant, including that of the acs operon that is involved in achromobactin biosynthesis and transport. This siderophore is required for full virulence of E. chrysanthemi, and its expression is governed by the global repressor protein Fur. Changes in gene expression were also observed for membrane transporters, stress-related genes, toxins, and transcriptional regulators. Our results indicate that the PhoPQ system governs the expression of several additional virulence factors and may also be involved in interactions with other regulatory systems.

scholarly journals Cytokinin-Regulated Expression of Arabidopsis thaliana PAP Genes and Its Implication for the Expression of Chloroplast-Encoded Genes

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1658
Author(s):  
Aleksandra A. Andreeva ◽  
Radomira Vankova ◽  
Ivan A. Bychkov ◽  
Natalia V. Kudryakova ◽  
Maria N. Danilova ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Nuclear Genes ◽  
Promoter Regions ◽  
Knock Out ◽  
Regulatory Circuit ◽  
Associated Proteins ◽  
Gene Transcripts ◽  
Plastid Rna Polymerase ◽  
Underlying Mechanisms

Cytokinins (CKs) are known to regulate the biogenesis of chloroplasts under changing environmental conditions and at different stages of plant ontogenesis. However, the underlying mechanisms are still poorly understood. Apparently, the mechanisms can be duplicated in several ways, including the influence of nuclear genes that determine the expression of plastome through the two-component CK regulatory circuit. In this study, we evaluated the role of cytokinins and CK signaling pathway on the expression of nuclear genes for plastid RNA polymerase-associated proteins (PAPs). Cytokinin induced the expression of all twelve Arabidopsis thalianaPAP genes irrespective of their functions via canonical CK signaling pathway but this regulation might be indirect taking into consideration their different functions and versatile structure of promoter regions. The disruption of PAP genes contributed to the abolishment of positive CK effect on the accumulation of the chloroplast gene transcripts and transcripts of the nuclear genes for plastid transcription machinery as can be judged from the analysis of pap1 and pap6 mutants. However, the CK regulatory circuit in the mutants remained practically unperturbed. Knock-out of PAP genes resulted in cytokinin overproduction as a consequence of the strong up-regulation of the genes for CK synthesis.

scholarly journals PecS and PecT Coregulate the Synthesis of HrpN and Pectate Lyases, Two Virulence Determinants in Erwinia chrysanthemi 3937

2005 ◽  
Vol 18 (11) ◽  
pp. 1205-1214 ◽  
Author(s):  
William Nasser ◽  
Sylvie Reverchon ◽  
Regine Vedel ◽  
Martine Boccara
Keyword(s):  
Regulatory Region ◽  
Soft Rot ◽  
Erwinia Chrysanthemi ◽  
Virulence Determinants ◽  
Pectate Lyases ◽  
Heat Stable ◽  
Pectinolytic Enzymes ◽  
Transcript Elongation ◽  
Dna Protein Interaction

Erwinia chrysanthemi strain 3937 is a necrotrophic bacterial plant pathogen. Pectinolytic enzymes and, in particular, pectate lyases play a key role in soft rot symptoms; however, the efficient colonization of plants by E. chrysanthemi requires additional factors. These factors include HrpN (harpin), a heat-stable, glycine-rich hydrophilic protein, which is secreted by the type III secretion system. We investigated the expression of hrpN in E. chrysanthemi 3937 in various environmental conditions and different regulatory backgrounds. Using lacZ fusions, hrpN expression was markedly influenced by the carbon source, osmolarity, growth phase, and growth substrate. hrpN was repressed when pectinolysis started and negatively regulated by the repressors of ectate lyase synthesis, PecS and PecT. Primer extension data and in vitro DNA-protein interaction experiments support a model whereby PecS represses hrpN expression by binding to the hrpN regulatory region and inhibiting transcript elongation. The results suggest coordinated regulation of HrpN and pectate lyases by PecS and PecT. A putative model of the synthesis of these two virulence factors in E. chrysanthemi during pathogenesis is presented.

scholarly journals Influence of Soil Saturation and Temperature on Erwinia chrysanthemi Soft Rot of Carrot

Plant Disease ◽  
2000 ◽  
Vol 84 (6) ◽  
pp. 665-668 ◽  
Author(s):  
J. J. Farrar ◽  
J. J. Nunez ◽  
R. M. Davis
Keyword(s):  
Disease Severity ◽  
High Temperatures ◽  
Weight Reduction ◽  
Soft Rot ◽  
Saturated Soil ◽  
Erwinia Chrysanthemi ◽  
Optimum Conditions ◽  
First Report ◽  
Soil Temperatures ◽  
Increasing Temperature

In 1998, soft rot caused by Erwinia chrysanthemi resulted in an estimated loss of 1,800 tons of carrots in California. The disease appeared to be related to unusually high temperatures and excessive irrigation. To determine the optimum conditions for development of soft rot under controlled conditions, pots of carrots inoculated with E. chrysanthemi were saturated with water and incubated at 20, 25, 30, or 35°C. Plants were harvested and examined for disease 12, 24, 36, 48, 72, and 96 h after inoculation. Negligible disease occurred after 12 h. Disease severity and incidence increased with increasing temperature and duration of saturation from 24 to 96 h. In a second experiment, carrot disks were inoculated with three isolates each of E. chrysanthemi and E. carotovora subsp. carotovora and incubated at 15, 20, 25, 30, and 35°C. After 48 h, the disks were washed to remove rotted tissue and reweighed. Neither bacterium reduced carrot disk weight at 15°C. In general, moderate weight reduction occurred at 20 and 25°C. The greatest degree of soft rot was caused by E. chrysanthemi at 30 and 35°C. E. carotovora subsp. carotovora isolates were relatively less virulent than E. chrysanthemi at 30°C and none of the E. carotovora subsp. carotovora isolates reduced carrot disk weight at 35°C. This is the first report of E. chrysanthemi causing soft rot of carrot in California. Based on these results, growers should limit the length of time carrot roots are exposed to saturated soil, especially at high soil temperatures.

scholarly journals Expression of Erwinia chrysanthemi Pectinase Genes pelI, pelL, and pelZ During Infection of Potato Tubers

1999 ◽  
Vol 12 (10) ◽  
pp. 845-851 ◽  
Author(s):  
Sylwia Jafra ◽  
Izabela Figura ◽  
Nicole Hugouvieux-Cotte-Pattat ◽  
Ewa Lojkowska
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Pectate Lyase ◽  
Soft Rot ◽  
Erwinia Chrysanthemi ◽  
Potato Tubers ◽  
Wild Type ◽  
In Planta ◽  
Gene Encoding ◽  
Glucuronidase Activity

Erwinia chrysanthemi mutants, containing transcriptional fusions of one of the minor pectate lyase genes (pelI, pelL, pelZ) with the reporter gene encoding β-glucuronidase activity, were studied for their ability to cause disease symptoms and to synthesize pectinases after inoculation of potato tubers. The strains affected in pelI and pelL genes displayed reduced virulence on potato tubers, demonstrating the important role of these isoenzymes in soft rot disease. Inactivation of the pelZ gene slightly influences the ability to macerate. Analysis of the bacterial population showed rapid multiplication of bacteria during infection. Similar kinetics of growth were observed for all mutants and for the wild-type strain. Comparison of the mutants and the wild-type strain showed that the pelI, pelL, and pelZ mutants synthesized reduced levels of Pels. The expression of pelZ is fivefold higher in planta than in bacterial cultures. In contrast, both pelI and pelL are highly (10-fold factor) induced in planta, which is characteristic of the plant-inducible pectate lyases.

scholarly journals First Report of Bacterial Soft Rot of White Flowered Calla Lily Caused by Erwinia chrysanthemi in Taiwan

Plant Disease ◽  
2002 ◽  
Vol 86 (11) ◽  
pp. 1273-1273 ◽  
Author(s):  
Y.-A. Lee ◽  
K.-P. Chen ◽  
Y.-C. Chang
Keyword(s):  
Soft Rot ◽  
Sweet Pepper ◽  
Erwinia Chrysanthemi ◽  
Maximum Temperature ◽  
Gram Negative ◽  
First Report ◽  
Zantedeschia Aethiopica ◽  
Calla Lily ◽  
Arginine Dihydrolase ◽  
Indole Production

In 2002, soft rot symptoms on white flowered calla lily (Zantedeschia aethiopica) were found in some nurseries in the Yang Ming Shan area, Taipei, Taiwan. The disease was characterized by foul smelling rot and collapse of flower stems. Isolations from diseased flower stems consistently yielded bacterial colonies that were translucent, white, and glistening on nutrient agar. Ten representative isolates were chosen for further characterization. All isolates were gram-negative rods, facultatively anaerobic, sensitive to erythromycin (25 μg/ml), negative for oxidase and arginine dihydrolase, and positive for catalase, phosphatase, tryptophanase (indole production), and lecithinase. They fermented glucose and reduced nitrates to nitrites. The maximum temperature for growth was 37°C. The isolates hydrolyzed gelatin and esculin, produced acids from utilizing D(+)-glucose, melibiose, amygdalin, L(+)-arabinose, D-mannitol, and sucrose, but not from trehalose, lactose, D-sorbitol, or maltose. They degraded pectate and rotted potato, carrot, sweet pepper, and onion slices. Bacterial suspensions (108 CFU/ml) were injected in stems of white flowered calla lily to fulfill Koch's postulates. Control plants were inoculated with sterile distilled water. Inoculated plants were kept in a growth chamber at 30°C. Symptoms developed 1 to 2 days in all four inoculated plants and appeared to be identical to those observed on diseased material in nurseries. The four control plants did not rot. The bacterium was readily reisolated from diseased plants, confirmed to be the inoculated pathogen, and identified as Erwinia chrysanthemi. E. carotovora subsp. carotovora has been reported to cause soft rot of other calla lilies, such as Zantedeschia sp. cvs. Black Magic and Pink Persuasion and Z. elliottiana in Taiwan (1). However, to our knowledge, this is the first report of soft rot caused by E. chrysanthemi on white flowered calla lily in Taiwan. Reference: (1) S. T. Hsu and K. C. Tzeng. Pages 9–18 in: Proc. Int. Conf. Plant Path. Bact., 5th. J. C. Lozano, ed. CIAT, Cali, Colombia, 1981.

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