scholarly journals Effects of Light and Daytime on the Regulation of Chitosan-Induced Stomatal Responses and Defence in Tomato Plants

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 59 ◽  
Author(s):  
Zalán Czékus ◽  
Péter Poór ◽  
Irma Tari ◽  
Attila Ördög
Keyword(s):  
Stomatal Closure ◽  
Plant Defence ◽  
Guard Cells ◽  
Ethylene Response Factor ◽  
Mesophyll Cells ◽  
Dark Light ◽  
Tomato Plants ◽  
Pathogenesis Related ◽  
Defence Responses ◽  
Plant Defence Responses

Closure of stomata upon pathogenesis is among the earliest plant immune responses. However, our knowledge is very limited about the dependency of plant defence responses to chitosan (CHT) on external factors (e.g., time of the day, presence, or absence of light) in intact plants. CHT induced stomatal closure before dark/light transition in leaves treated at 17:00 hrs and stomata were closed at 09:00 hrs in plants treated at dawn and in the morning. CHT was able to induce generation of reactive oxygen species (ROS) in guard cells in the first part of the light phase, but significant nitric oxide production was observable only at 15:00 hrs. The actual quantum yield of PSII electron transport (ΦPSII) decreased upon CHT treatments at 09:00 hrs in guard cells but it declined only at dawn in mesophyll cells after the treatment at 17:00 hrs. Expression of Pathogenesis-related 1 (PR1) and Ethylene Response Factor 1 were already increased at dawn in the CHT-treated leaves but PR1 expression was inhibited in the dark. CHT-induced systemic response was also observed in the distal leaves of CHT-treated ones. Our results suggest a delayed and daytime-dependent defence response of tomato plants after CHT treatment at night and under darkness.

scholarly journals Activation of Local and Systemic Defence Responses by Flg22 Is Dependent on Daytime and Ethylene in Intact Tomato Plants

2021 ◽  
Vol 22 (15) ◽  
pp. 8354
Author(s):  
Zalán Czékus ◽  
András Kukri ◽  
Kamirán Áron Hamow ◽  
Gabriella Szalai ◽  
Irma Tari ◽  
...  
Keyword(s):  
Stomatal Closure ◽  
Plant Defence ◽  
Time Of Day ◽  
Light Period ◽  
Ethylene Response Factor ◽  
Wild Type ◽  
Tomato Plants ◽  
Production Of Hydrogen ◽  
Pathogenesis Related ◽  
Defence Responses

The first line of plant defence responses against pathogens can be induced by the bacterial flg22 and can be dependent on various external and internal factors. Here, we firstly studied the effects of daytime and ethylene (ET) using Never ripe (Nr) mutants in the local and systemic defence responses of intact tomato plants after flg22 treatments. Flg22 was applied in the afternoon and at night and rapid reactions were detected. The production of hydrogen peroxide and nitric oxide was induced by flg22 locally, while superoxide was induced systemically, in wild type plants in the light period, but all remained lower at night and in Nr leaves. Flg22 elevated, locally, the ET, jasmonic acid (JA) and salicylic acid (SA) levels in the light period; these levels did not change significantly at night. Expression of Pathogenesis-related 1 (PR1), Ethylene response factor 1 (ERF1) and Defensin (DEF) showed also daytime- and ET-dependent changes. Enhanced ERF1 and DEF expression and stomatal closure were also observable in systemic leaves of wild type plants in the light. These data demonstrate that early biotic signalling in flg22-treated leaves and distal ones is an ET-dependent process and it is also determined by the time of day and inhibited in the early night phase.

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.

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 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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