scholarly journals A glutamate synthase mutant of Bradyrhizobium sp. strain ORS285 is unable to induce nodules on Nod factor-independent Aeschynomene species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nico Nouwen ◽  
Clémence Chaintreuil ◽  
Joel Fardoux ◽  
Eric Giraud
Keyword(s):  
Wild Type Strain ◽  
Plant Defence ◽  
Glutamate Synthase ◽  
Nitrogen Sources ◽  
Symbiotic Interaction ◽  
Nod Factor ◽  
Bradyrhizobium Sp ◽  
Defence Responses ◽  
Plant Defence Responses ◽  
Free Living Conditions

AbstractThe Bradyrhizobium sp. strain ORS285 is able to establish a nitrogen-fixing symbiosis with both Nod factor (NF) dependent and NF-independent Aeschynomene species. Here, we have studied the growth characteristics and symbiotic interaction of a glutamate synthase (GOGAT; gltD::Tn5) mutant of Bradyrhizobium ORS285. We show that the ORS285 gltD::Tn5 mutant is unable to use ammonium, nitrate and many amino acids as nitrogen source for growth and is unable to fix nitrogen under free-living conditions. Moreover, on several nitrogen sources, the growth rate of the gltB::Tn5 mutant was faster and/or the production of the carotenoid spirilloxanthin was much higher as compared to the wild-type strain. The absence of GOGAT activity has a drastic impact on the symbiotic interaction with NF-independent Aeschynomene species. With these species, inoculation with the ORS285 gltD::Tn5 mutant does not result in the formation of nodules. In contrast, the ORS285 gltD::Tn5 mutant is capable to induce nodules on NF-dependent Aeschynomene species, but these nodules were ineffective for nitrogen fixation. Interestingly, in NF-dependent and NF-independent Aeschynomene species inoculation with the ORS285 gltD::Tn5 mutant results in browning of the plant tissue at the site of the infection suggesting that the mutant bacteria induce plant defence responses.

Microbial elicitors of plant defence responses activate transcription of a retrotransposon

1994 ◽  
Vol 5 (4) ◽  
pp. 535-542 ◽  
Author(s):  
Sylvie Pouteau ◽  
Marie-Angele Grandbastien ◽  
Martine Boccara
Keyword(s):  
Plant Defence ◽  
Defence Responses ◽  
Plant Defence Responses

scholarly journals Zinc phosphate protects tomato plants against Pseudomonas syringae pv. tomato

2021 ◽  
Author(s):  
Mara Quaglia ◽  
Marika Bocchini ◽  
Benedetta Orfei ◽  
Roberto D’Amato ◽  
Franco Famiani ◽  
...  
Keyword(s):  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Zinc Phosphate ◽  
Plant Defence ◽  
In Planta ◽  
Tomato Plants ◽  
Pathogenesis Related Protein ◽  
Defence Responses ◽  
Plant Defence Responses

AbstractThe purpose of this study was to determine whether zinc phosphate treatments of tomato plants (Solanum lycopersicum L.) can attenuate bacterial speck disease severity through reduction of Pseudomonas syringae pv. tomato (Pst) growth in planta and induce morphological and biochemical plant defence responses. Tomato plants were treated with 10 ppm (25.90 µM) zinc phosphate and then spray inoculated with strain DAPP-PG 215, race 0 of Pst. Disease symptoms were recorded as chlorosis and/or necrosis per leaf (%) and as numbers of necrotic spots. Soil treatments with zinc phosphate protected susceptible tomato plants against Pst, with reductions in both disease severity and pathogen growth in planta. The reduction of Pst growth in planta combined with significantly higher zinc levels in zinc-phosphate-treated plants indicated direct antimicrobial toxicity of this microelement, as also confirmed by in vitro assays. Morphological (i.e. callose apposition) and biochemical (i.e., expression of salicylic-acid-dependent pathogenesis-related protein PR1b1 gene) defence responses were induced by the zinc phosphate treatment, as demonstrated by histochemical and qPCR analyses, respectively. In conclusion, soil treatments with zinc phosphate can protect tomato plants against Pst attacks through direct antimicrobial activity and induction of morphological and biochemical plant defence responses.

scholarly journals Integrating metabolomics and targeted gene expression to uncover potential biomarkers of fungal/oomycetes-associated disease susceptibility in grapevine

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marisa Maia ◽  
António E. N. Ferreira ◽  
Rui Nascimento ◽  
Filipa Monteiro ◽  
Francisco Traquete ◽  
...  
Keyword(s):  
Gene Expression ◽  
Plant Defence ◽  
Breeding Programs ◽  
Analysis Group ◽  
Expression Of Genes ◽  
Leucoanthocyanidin Reductase ◽  
Defence Responses ◽  
Targeted Gene Expression ◽  
Plant Defence Responses ◽  
First Time

Abstract Vitis vinifera, one of the most cultivated fruit crops, is susceptible to several diseases particularly caused by fungus and oomycete pathogens. In contrast, other Vitis species (American, Asian) display different degrees of tolerance/resistance to these pathogens, being widely used in breeding programs to introgress resistance traits in elite V. vinifera cultivars. Secondary metabolites are important players in plant defence responses. Therefore, the characterization of the metabolic profiles associated with disease resistance and susceptibility traits in grapevine is a promising approach to identify trait-related biomarkers. In this work, the leaf metabolic composition of eleven Vitis genotypes was analysed using an untargeted metabolomics approach. A total of 190 putative metabolites were found to discriminate resistant/partial resistant from susceptible genotypes. The biological relevance of discriminative compounds was assessed by pathway analysis. Several compounds were selected as promising biomarkers and the expression of genes coding for enzymes associated with their metabolic pathways was analysed. Reference genes for these grapevine genotypes were established for normalisation of candidate gene expression. The leucoanthocyanidin reductase 2 gene (LAR2) presented a significant increase of expression in susceptible genotypes, in accordance with catechin accumulation in this analysis group. Up to our knowledge this is the first time that metabolic constitutive biomarkers are proposed, opening new insights into plant selection on breeding programs.

Influence of selected plant amines on probing behaviour of bird cherry-oat aphid (Rhopalosiphum padi L.)

2016 ◽  
Vol 106 (3) ◽  
pp. 368-377 ◽  
Author(s):  
C. Sempruch ◽  
S. Goławska ◽  
P. Osiński ◽  
B. Leszczyński ◽  
P. Czerniewicz ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Rhopalosiphum Padi ◽  
Plant Defence ◽  
Study Results ◽  
Electrical Penetration Graphs ◽  
Defence Responses ◽  
Plant Defence Responses ◽  
Common Plant ◽  
Probing Behaviour

AbstractThe study aimed to quantify the influence of common plant polyamines and tyramine on probing behaviour in the bird cherry-oat aphid (Rhopalosiphum padi L.). Electrical penetration graphs (DC) were used to monitor the probing and feeding behaviour of R. padi exposed to the amines agmatine, cadaverine, putrescine, spermidine, spermine and tyramine. The study results showed that the analyzed amines tended to shorten the stylet activity of aphids in the gels (as indicated by the g-C pattern), prolong the duration of non-probing behaviour (g-np pattern) and decrease salivation into the gels (g-E1pattern) and ingestion from the gels (g-G pattern). The 10 mM concentration of the studied amines, especially cadaverine, reduced or completely inhibited aphid ingestion. The obtained results demonstrate that plant amines participate in plant defence responses to R. padi through disturbance of its probing behaviour and the intensity of such effects is concentration dependent.

Plant-specific VQ-domain proteins as interaction partners of WRKY transcription factors

2014 ◽  
Vol 12 (S1) ◽  
pp. S121-S124
Author(s):  
Soon Il Kwon ◽  
D. J. Hwang
Keyword(s):  
Transcription Factors ◽  
Biological Effects ◽  
Plant Stress ◽  
Plant Defence ◽  
Genomic Analysis ◽  
Wrky Transcription Factors ◽  
Defence Mechanisms ◽  
Interaction Partners ◽  
Defence Responses ◽  
Plant Defence Responses

VQ-domain proteins are known to interact with WRKY transcription factors and have been reported to be involved in plant defence responses to environmental stresses in Arabidopsis. Thus, elucidation of the defence mechanisms during the interaction of VQ-domain proteins and WRKY transcription factors could provide useful insights into the regulation of VQ-domain protein-mediated WRKY transcription factors. As the focus of this review, we summarize the genomic analysis of the VQ-domain proteins as one of the WRKY-interacting proteins and their biological effects during plant stress conditions in Arabidopsis and rice.

The SEN1 gene of Arabidopsis is regulated by signals that link plant defence responses and senescence

2005 ◽  
Vol 43 (10-11) ◽  
pp. 997-1005 ◽  
Author(s):  
Peer M. Schenk ◽  
Kemal Kazan ◽  
Anca G. Rusu ◽  
John M. Manners ◽  
Donald J. Maclean
Keyword(s):  
Plant Defence ◽  
Defence Responses ◽  
Plant Defence Responses

scholarly journals Biological effects of oomycetes elicitins

2019 ◽  
Vol 56 (No. 1) ◽  
pp. 1-8
Author(s):  
Martina Janků ◽  
Lucie Činčalová ◽  
Lenka Luhová ◽  
Jan Lochman ◽  
Marek Petřivalský
Keyword(s):  
Molecular Mechanisms ◽  
Biological Effects ◽  
Plant Defence ◽  
Plant Host ◽  
Low Concentrations ◽  
Specific Pathogen ◽  
Defence Responses ◽  
Structure Perception ◽  
Molecular Patterns ◽  
Plant Defence Responses

Successful plant defence responses to pathogen challenges are based on fast and specific pathogen recognition and plant reaction mechanisms. Elicitins, proteinaceous elicitors secreted by the Phytophthora and Pythium species, were first described in Phytophthora culture filtrates as proteins able to induce a hypersensitive response (HR) and resistance in tobacco at low concentrations. Later, they were classified as microbial-associated molecular patterns (MAMPs) able to induce defences in a variety of plant species. In this review, we present a comprehensive summary of the actual knowledge on the representative elicitins and their structure, perception and activation of plant signalling pathways. The current research of elicitins has been focused on a detailed understanding of the molecular mechanisms of the elicitin recognition by plant cells. Moreover, the possibility of elicitin involvement in the establishment and enhancement of plant host resistance to a broad spectrum of pathogens has been intensively studied.

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