scholarly journals Interacting Signal Pathways Control Defense Gene Expression in Arabidopsis in Response to Cell Wall-Degrading Enzymes from Erwinia carotovora

2000 ◽  
Vol 13 (4) ◽  
pp. 430-438 ◽  
Author(s):  
Cecilia Norman-Setterblad ◽  
Sabina Vidal ◽  
E. Tapio Palva
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Target Genes ◽  
Plant Cell Wall ◽  
Erwinia Carotovora ◽  
Signal Pathways ◽  
Cell Wall Degrading Enzymes ◽  
Defense Gene Expression ◽  
Defense Gene ◽  
Degrading Enzymes

We have characterized the role of salicylic acid (SA)-independent defense signaling in Arabidopsis thaliana in response to the plant pathogen Erwinia carotovora subsp. carotovora. Use of pathway-specific target genes as well as signal mutants allowed us to elucidate the role and interactions of ethylene, jasmonic acid (JA), and SA signal pathways in this response. Gene expression studies suggest a central role for both ethylene and JA pathways in the regulation of defense gene expression triggered by the pathogen or by plant cell wall-degrading enzymes (CF) secreted by the pathogen. Our results suggest that ethylene and JA act in concert in this regulation. In addition, CF triggers another, strictly JA-mediated response inhibited by ethylene and SA. SA does not appear to have a major role in activating defense gene expression in response to CF. However, SA may have a dual role in controlling CF-induced gene expression, by enhancing the expression of genes synergistically induced by ethylene and JA and repressing genes induced by JA alone.

scholarly journals Oligogalacturonide-Mediated Induction of a Gene Involved in Jasmonic Acid Synthesis in Response to the Cell-Wall-Degrading Enzymes of the Plant Pathogen Erwinia carotovora

1999 ◽  
Vol 12 (7) ◽  
pp. 640-644 ◽  
Author(s):  
Cecilia Norman ◽  
Sabina Vidal ◽  
E. Tapio Palva
Keyword(s):  
Cell Wall ◽  
Plant Cell Wall ◽  
Extracellular Enzymes ◽  
Erwinia Carotovora ◽  
Acid Synthesis ◽  
Allene Oxide ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
High Sequence Homology ◽  
Oxide Synthase

Identification of Arabidopsis thaliana genes responsive to plant cell-wall-degrading enzymes of Erwinia carotovora subsp. carotovora led to the isolation of a cDNA clone with high sequence homology to the gene for allene oxide synthase, an enzyme involved in the biosynthesis of jasmonates. Expression of the corresponding gene was induced by the extracellular enzymes from this pathogen as well as by treatment with methyl jasmonate and short oligogalacturonides (OGAs). This suggests that OGAs are involved in the induction of the jasmonate pathway during plant defense response to E. carotovora subsp. carotovora attack.

scholarly journals Two-Component Regulators Involved in the Global Control of Virulence in Erwinia carotovora subsp. carotovora

1998 ◽  
Vol 11 (8) ◽  
pp. 743-752 ◽  
Author(s):  
Anders R. B. Eriksson ◽  
Robert A. Andersson ◽  
Minna Pirhonen ◽  
E. Tapio Palva
Keyword(s):  
Cell Wall ◽  
Gene Product ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Response Regulator ◽  
Erwinia Carotovora ◽  
Sensor Kinase ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Two Component

Production of extracellular, plant cell wall degrading enzymes, the main virulence determinants of the plant pathogen Erwinia carotovora subsp. carotovora, is coordinately controlled by a complex regulatory network. Insertion mutants in the exp (extracellular enzyme production) loci exhibit pleiotropic defects in virulence and the growth-phase-dependent transcriptional activation of genes encoding extracellular enzymes. Two new exp mutations, designated expA and expS, were characterized. Introduction of the corresponding wild-type alleles to the mutants complemented both the lack of virulence and the impaired production of plant cell wall degrading enzymes. The expA gene was shown to encode a 24-kDa polypeptide that is structurally and functionally related to the uvrY gene product of Escherichia coli and the GacA response regulator of Pseudomonas fluorescens. Functional similarity of expA and uvrY was demonstrated by genetic complementation. The expA gene is organized in an operon together with a uvrC-like gene, identical to the organization of uvrY and uvrC in E. coli. The unlinked expS gene encodes a putative sensor kinase that shows 92% identity to the recently described rpfA gene product from another E. carotovora subsp. carotovora strain. Our data suggest that ExpS and ExpA are members of two-component sensor kinase and response regulator families, respectively. These two proteins might interact in controlling virulence gene expression in E. carotovora subsp. carotovora.

scholarly journals The regulatory and transcriptional landscape associated with carbon utilization in a filamentous fungus

2020 ◽  
Vol 117 (11) ◽  
pp. 6003-6013 ◽  
Author(s):  
Vincent W. Wu ◽  
Nils Thieme ◽  
Lori B. Huberman ◽  
Axel Dietschmann ◽  
David J. Kowbel ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Carbon Sources ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes ◽  
Genes Encoding

Filamentous fungi, such asNeurospora crassa, are very efficient in deconstructing plant biomass by the secretion of an arsenal of plant cell wall-degrading enzymes, by remodeling metabolism to accommodate production of secreted enzymes, and by enabling transport and intracellular utilization of plant biomass components. Although a number of enzymes and transcriptional regulators involved in plant biomass utilization have been identified, how filamentous fungi sense and integrate nutritional information encoded in the plant cell wall into a regulatory hierarchy for optimal utilization of complex carbon sources is not understood. Here, we performed transcriptional profiling ofN. crassaon 40 different carbon sources, including plant biomass, to provide data on how fungi sense simple to complex carbohydrates. From these data, we identified regulatory factors inN. crassaand characterized one (PDR-2) associated with pectin utilization and one with pectin/hemicellulose utilization (ARA-1). Using in vitro DNA affinity purification sequencing (DAP-seq), we identified direct targets of transcription factors involved in regulating genes encoding plant cell wall-degrading enzymes. In particular, our data clarified the role of the transcription factor VIB-1 in the regulation of genes encoding plant cell wall-degrading enzymes and nutrient scavenging and revealed a major role of the carbon catabolite repressor CRE-1 in regulating the expression of major facilitator transporter genes. These data contribute to a more complete understanding of cross talk between transcription factors and their target genes, which are involved in regulating nutrient sensing and plant biomass utilization on a global level.

scholarly journals Pyramiding Unmarked Deletions in Ralstonia solanacearum Shows That Secreted Proteins in Addition to Plant Cell-Wall-Degrading Enzymes Contribute to Virulence

2005 ◽  
Vol 18 (12) ◽  
pp. 1296-1305 ◽  
Author(s):  
Huanli Liu ◽  
Shuping Zhang ◽  
Mark A. Schell ◽  
Timothy P. Denny
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Ralstonia Solanacearum ◽  
Plant Cell Wall ◽  
Secreted Proteins ◽  
Cellulolytic Enzymes ◽  
Wild Type ◽  
Cell Wall Degrading Enzymes ◽  
Tomato Plants ◽  
Degrading Enzymes

Ralstonia solanacearum, like many phytopathogenic bacteria, makes multiple extracellular plant cell-wall-degrading enzymes (CWDE), some of which contribute to its ability to cause wilt disease. CWDE and many other proteins are secreted to the milieu via the highly conserved type II protein secretion system (T2SS). R. solanacearum with a defective T2SS is weakly virulent, but it is not known whether this is due to absence of all the CWDE or the loss of other secreted proteins that contribute to disease. These alternatives were investigated by creating mutants of wild-type strain GMI1000 lacking either the T2SS or up to six CWDE and comparing them for virulence on tomato plants. To create unmarked deletions, genomic regions flanking the target gene were polymerase chain reaction (PCR)-amplified, were fused using splice overlap extension PCR, were cloned into a suicide plasmid harboring the sacB counter-selectable marker, and then, were site-specifically introduced into the genome. Various combinations of five deletions (δpehA, δpehB, δpehC, δpme, and δegl) and one inactivated allele (cbhA::aphA-3) resulted in 15 mutants missing one to six CWDE. In soil-drench inoculation assays, virulence of mutants lacking only pectic enzymes (PehA, PehB, PehC, and Pme) was not statistically different from GMI1000, but all the mutants lacking one or both cellulolytic enzymes (Egl or CbhA) wilted plants significantly more slowly than did the wild type. The GMI-6 mutant that lacks all six CWDE was more virulent than the mutant lacking only its two cellulolytic enzymes, and both were significantly more virulent than the T2SS mutant (GMI-D). Very similar results were observed in wounded-petiole inoculation assays, so GMI-6 and GMI-D appear to be less capable of colonizing tomato tissues after invasion. Because the T2SS mutant was much less virulent than the sixfold CWDE mutant, we conclude that other secreted proteins contribute substantially to the ability of R. solanacearum GMI1000 to systemically colonize tomato plants.

scholarly journals Neotropical termite microbiomes as sources of novel plant cell wall degrading enzymes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Matias Romero Victorica ◽  
Marcelo A. Soria ◽  
Ramón Alberto Batista-García ◽  
Javier A. Ceja-Navarro ◽  
Surendra Vikram ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes
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