scholarly journals Role of ethylene and light in chitosan-induced local and systemic defence responses of tomato plants

2021 ◽  
pp. 153461
Author(s):  
Zalán Czékus ◽  
Nadeem Iqbal ◽  
Boglárka Pollák ◽  
Atina Martics ◽  
Attila Ördög ◽  
...  
Keyword(s):  
Tomato Plants ◽  
Defence Responses

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.

scholarly journals Ralstonia solanacearum Needs Motility for Invasive Virulence on Tomato

2001 ◽  
Vol 183 (12) ◽  
pp. 3597-3605 ◽  
Author(s):  
Julie Tans-Kersten ◽  
Huayu Huang ◽  
Caitilyn Allen
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Soft Agar ◽  
Cell Protein ◽  
In Planta ◽  
Tomato Plants ◽  
Bacterial Wilt Disease ◽  
Virulence Assay ◽  
Flagellar Filament

ABSTRACT Ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. By examining bacteria from the xylem vessels of infected plants, we found thatR. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. To determine the role of pathogen motility in this disease, we cloned, characterized, and mutated two genes in the R. solanacearum flagellar biosynthetic pathway. The genes for flagellin, the subunit of the flagellar filament (fliC), and for the flagellar motor switch protein (fliM) were isolated based on their resemblance to these proteins in other bacteria. As is typical for flagellins, the predicted FliC protein had well-conserved N- and C-terminal regions, separated by a divergent central domain. The predicted R. solanacearum FliM closely resembled motor switch proteins from other proteobacteria. Chromosomal mutants lackingfliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphAcassette was used to make a nonpolar fliM mutation. Both mutants were completely nonmotile on soft agar plates, in minimal broth, and in tomato plants. The fliC mutant lacked flagella altogether; moreover, sheared-cell protein preparations from the fliC mutant lacked a 30-kDa band corresponding to flagellin. The fliM mutant was usually aflagellate, but about 10% of cells had abnormal truncated flagella. In a biologically representative soil-soak inoculation virulence assay, both nonmotile mutants were significantly reduced in the ability to cause disease on tomato plants. However, the fliC mutant had wild-type virulence when it was inoculated directly onto cut tomato petioles, an inoculation method that did not require bacteria to enter the intact host from the soil. These results suggest that swimming motility makes its most important contribution to bacterial wilt virulence in the early stages of host plant invasion and colonization.

ROLE OF ROOTSTOCKS ON ION UPTAKE OF TOMATO PLANTS GROWN UNDER SALINE CONDITIONS

2009 ◽  
pp. 637-642 ◽  
Author(s):  
G.B. Öztekin ◽  
C. Leonardi ◽  
E. Caturano ◽  
M. Martorana ◽  
Y. Tüzel
Keyword(s):  
Ion Uptake ◽  
Tomato Plants

scholarly journals Comparison of defence responses to Botrytis cinerea infection in tomato plants propagated in vitro and grown in vivo

2013 ◽  
Vol 49 (1-2) ◽  
pp. 115-121 ◽  
Author(s):  
Jacek Patykowski ◽  
Elżbieta Kuźniak ◽  
Henryk Urbaniak
Keyword(s):  
Superoxide Dismutase ◽  
Botrytis Cinerea ◽  
Ascorbate Peroxidase ◽  
Guaiacol Peroxidase ◽  
Activity Increase ◽  
Tomato Plants ◽  
Defence Responses ◽  
Defence Reactions

Defence reactions: O<sub>2<sub> - generation, superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase activities after <em>B. cinerea</em> infection in tomato plants propagated <em>in vitro</em> and grown <em>in vivo</em> have been compared. Infection resulted in rapid O<sub>2<sub> - generation. Superoxide dismutase activity increase was slower than O<sub>2<sub> - response. In plants propagated <em>in vitro</em> catalase and guaiacol peroxidase activities after infection were induced less strongly than in plants grown <em>in vivo</em>. K<sub>2<sub>HPO<sub>4<sub> pretreatment of plants grown <em>in vitro</em> enhanced significantly the activities of catalase and guaiacol peroxidase after infection. Slight restriction of <em>B. cinerea</em> infection development in <em>in vitro</em> propagated plants pretreated with K<sub>2<sub>HP0<sub>4<sub> was observed.

Comparative analysis reveals gravity is involved in the MIZ1-regulated root hydrotropism

2020 ◽  
Vol 71 (22) ◽  
pp. 7316-7330
Author(s):  
Ying Li ◽  
Wei Yuan ◽  
Luocheng Li ◽  
Hui Dai ◽  
Xiaolin Dang ◽  
...  
Keyword(s):  
Water Potential ◽  
Double Mutant ◽  
Root Elongation ◽  
Vertical Orientation ◽  
Tomato Plants ◽  
Oblique Orientation ◽  
Experimental Systems ◽  
Potential Gradients ◽  
Insight Into

Abstract Hydrotropism is the directed growth of roots toward the water found in the soil. However, mechanisms governing interactions between hydrotropism and gravitropism remain largely unclear. In this study, we found that an air system and an agar–sorbitol system induced only oblique water-potential gradients; an agar–glycerol system induced only vertical water-potential gradients; and a sand system established both oblique and vertical water-potential gradients. We employed obliquely oriented and vertically oriented experimental systems to study hydrotropism in Arabidopsis and tomato plants. Comparative analyses using different hydrotropic systems showed that gravity hindered the ability of roots to search for obliquely oriented water, whilst facilitating roots’ search for vertically oriented water. We found that the gravitropism-deficient mutant aux1 showed enhanced hydrotropism in the oblique orientation but impaired root elongation towards water in the vertical orientation. The miz1 mutant exhibited deficient hydrotropism in the oblique orientation but normal root elongation towards water in the vertical orientation. Importantly, in contrast to miz1, the miz1/aux1 double mutant exhibited hydrotropic bending in the oblique orientation and attenuated root elongation towards water in the vertical orientation. Our results suggest that gravitropism is required for MIZ1-regulated root hydrotropism in both the oblique orientation and the vertical orientation, providing further insight into the role of gravity in root hydrotropism.

scholarly journals Expression of miR159 Is Altered in Tomato Plants Undergoing Drought Stress

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 201 ◽  
Author(s):  
María José López-Galiano ◽  
Inmaculada García-Robles ◽  
Ana I. González-Hernández ◽  
Gemma Camañes ◽  
Begonya Vicedo ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Regulatory Networks ◽  
Crop Yields ◽  
Insect Pest ◽  
Regulatory Function ◽  
Myb Transcription Factor ◽  
Regulation Of Transcription ◽  
Tomato Plants

In a scenario of global climate change, water scarcity is a major threat for agriculture, severely limiting crop yields. Therefore, alternatives are urgently needed for improving plant adaptation to drought stress. Among them, gene expression reprogramming by microRNAs (miRNAs) might offer a biotechnologically sound strategy. Drought-responsive miRNAs have been reported in many plant species, and some of them are known to participate in complex regulatory networks via their regulation of transcription factors involved in water stress signaling. We explored the role of miR159 in the response of Solanum lycopersicum Mill. plants to drought stress by analyzing the expression of sly-miR159 and its target SlMYB transcription factor genes in tomato plants of cv. Ailsa Craig grown in deprived water conditions or in response to mechanical damage caused by the Colorado potato beetle, a devastating insect pest of Solanaceae plants. Results showed that sly-miR159 regulatory function in the tomato plants response to distinct stresses might be mediated by differential stress-specific MYB transcription factor targeting. sly-miR159 targeting of SlMYB33 transcription factor transcript correlated with accumulation of the osmoprotective compounds proline and putrescine, which promote drought tolerance. This highlights the potential role of sly-miR159 in tomato plants’ adaptation to water deficit conditions.

scholarly journals miR168 targets Argonaute1A mediated miRNAs regulation pathways in response to potassium deficiency stress in tomato

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xin Liu ◽  
Chunchang Tan ◽  
Xin Cheng ◽  
Xiaoming Zhao ◽  
Tianlai Li ◽  
...  
Keyword(s):  
Root Growth ◽  
Transgenic Tomato ◽  
Integrated Analysis ◽  
Regulation Mechanism ◽  
Sequencing Analysis ◽  
Growth Modulation ◽  
Tomato Plants ◽  
Transgenic Tomato Plants ◽  
Low K

Abstract Background Potassium (K+) is an essential ion for most plants, as it is involved in the regulation of growth and development. K+ homeostasis in plant cells has evolved to facilitate plant adaptation to K+-deficiency stress. Argonaute1 (AGO1) is regulated by miR168 to modulate the small RNA regulatory pathway by RNA silencing complex (RISC) in tomatoes. However, the role of miR168-mediated regulation of AGO1 in the context of K+ deficiency stress in tomatoes has not been elucidated yet. Results SlmiR168 and its target gene SlAGO1A were differentially expressed among low-K+-tolerant JZ34 and low-K+-sensitive JZ18 tomato plants. Transgenic tomato plants constitutively expressing pri-SlmiR168a showed stronger root system growth, better leaves development, and higher K+ contents in roots under K+-deficiency stress than those of the transgenic tomato lines expressing rSlAGO1A (SlmiR168-resistant) and the wild type (WT). Deep sequencing analysis showed that 62 known microRNAs (miRNAs) were up-regulated in 35S:rSlAGO1 compared with WT tomatoes. The same miRNAs were down-regulated in 35S:SlmiR168a compared with WT plants. The integrated analysis found 12 miRNA/mRNA pairs from the 62 miRNAs, including the root growth and cytokinin (CTK)/abscisic acid (ABA) pathways. Conclusions The regulation mediated by SlmiR168 of SlAGO1A contributes to the plant development under low-K+ stress. Moreover, this regulation mechanism may influence downstream miRNA pathways in response to low-K+ stress through the CTK/ABA and root growth modulation pathways.

The role of NO in plant response to salt stress: interactions with polyamines

2020 ◽  
Vol 47 (10) ◽  
pp. 865
Author(s):  
Natalia Napieraj ◽  
Małgorzata Reda ◽  
Małgorzata Janicka
Keyword(s):  
Salt Stress ◽  
Higher Plants ◽  
Growth Parameters ◽  
Plant Response ◽  
No Donors ◽  
Signalling Molecule ◽  
Defence Responses ◽  
High Concentrations ◽  
Ionic Effects

Soil salinity is a major abiotic stress that limits plant growth and productivity. High concentrations of sodium chloride can cause osmotic and ionic effects. This stress minimises a plant’s ability to uptake water and minerals, and increases Na+ accumulation in the cytosol, thereby disturbing metabolic processes. Prolonged plant exposure to salt stress can lead to oxidative stress and increased production of reactive oxygen species (ROS). Higher plants developed some strategies to cope with salt stress. Among these, mechanisms involving nitric oxide (NO) and polyamines (PAs) are particularly important. NO is a key signalling molecule that mediates a variety of physiological functions and defence responses against abiotic stresses in plants. Under salinity conditions, NO donors increase growth parameters, reduce Na+ toxicity, maintain ionic homeostasis, stimulate osmolyte accumulation and prevent damages caused by ROS. NO enhances salt tolerance of plants via post-translational protein modifications through S-nitrosylation of thiol groups, nitration of tyrosine residues and modulation of multiple gene expression. Several reviews have reported on the role of polyamines in modulating salt stress plant response and the capacity to enhance PA synthesis upon salt stress exposure, and it is known that NO and PAs interact under salinity. In this review, we focus on the role of NO in plant response to salt stress, paying particular attention to the interaction between NO and PAs.

Role of plant hormones in plant defence responses

2008 ◽  
Vol 69 (4) ◽  
pp. 473-488 ◽  
Author(s):  
Rajendra Bari ◽  
Jonathan D. G. Jones
Keyword(s):  
Plant Hormones ◽  
Plant Defence ◽  
Defence Responses ◽  
Plant Defence Responses
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