scholarly journals Nitrate Efflux Is an Essential Component of the Cryptogein Signaling Pathway Leading to Defense Responses and Hypersensitive Cell Death in Tobacco

2002 ◽  
Vol 14 (8) ◽  
pp. 1937-1951 ◽  
Author(s):  
David Wendehenne ◽  
Olivier Lamotte ◽  
Jean-Marie Frachisse ◽  
Hélène Barbier-Brygoo ◽  
Alain Pugin
Keyword(s):  
Cell Death ◽  
Signaling Pathway ◽  
Defense Responses ◽  
Hypersensitive Cell Death ◽  
Essential Component

scholarly journals Induction of Hypersensitive Cell Death by a Fungal Protein in Cultures of Tobacco Cells

1998 ◽  
Vol 11 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Akira Yano ◽  
Kaoru Suzuki ◽  
Hirofumi Uchimiya ◽  
Hideaki Shinshi
Keyword(s):  
Cell Death ◽  
Specific Interaction ◽  
Trichoderma Viride ◽  
Defense Responses ◽  
Hypersensitive Reaction ◽  
Hypersensitive Cell Death ◽  
Tobacco Cells ◽  
Bright Yellow ◽  
Cell Death Program ◽  
Cellular Signal

Treatment of suspension-cultured tobacco (Nicotiana tabacum cv. Xanthi) cells (line XD6S) with fungal proteinaceous elicitors, namely, xylanase (EC 3.2.1.8) from Trichoderma viride (TvX) and xylanase from T. reesei (TrX), induced shrinkage of the cytoplasm, condensation of the nucleus, and, finally, cell death, which were accompanied by typical defense responses that included an oxidative burst and expression of defense genes. A Ca2+ channel blocker, Gd3+, inhibited the typical response of XD6S cells to TvX, which resembled the hypersensitive reaction (HR). These results suggested that the influx of Ca2+ ions plays an important role as a secondary signal. The HR was not observed in TvX-treated tobacco cells (line BY-2) derived from cv. Bright Yellow 2. This result suggests that key features of cultivar-specific interaction can be observed in cultures of tobacco cells. Xylanase from Bacillus circulans (BcX) and B. subtilis (BsX), which has enzymatic properties similar to those of TvX but an amino acid sequence different from that of TvX, did not induce the HR-like response in XD6S cells. These results suggest that the elicitor action of TvX is not due to its ability to hydrolyze cell walls but requires the TvX-specific recognition factors in plant cells. Thus, TvX-induced cell death was not due to some general toxic effect, but seems to be mediated by the activation of a specific cellular signal-transduction cascade that converges with a pathway that activates the intracellular cell death program.

Infection-induced rapid cell death in plants: a means of efficient pathogen defense

1995 ◽  
Vol 73 (S1) ◽  
pp. 426-434 ◽  
Author(s):  
Elmon Schmelzer ◽  
Beatrix Naton ◽  
Sibylle Freytag ◽  
Ila Rouhara ◽  
Bernhard Küster ◽  
...  
Keyword(s):  
Cell Death ◽  
Defense Response ◽  
Pathogenic Bacteria ◽  
Cultured Cells ◽  
Defense Responses ◽  
Hypersensitive Reaction ◽  
Cellular Level ◽  
Comprehensive Description ◽  
Hypersensitive Cell Death ◽  
Transient Activation

The hypersensitive reaction represents one of the major means by which plants actively defend themselves against infection by pathogenic bacteria, fungi, viruses, and nematodes. This complex defense reaction, often associated with the synthesis of phytoalexins (antimicrobial secondary metabolites), involves at the cellular level highly dynamic cytoplasmic rearrangements, rapid metabolic changes, and finally cell death. It also correlates with the rapid and transient activation of various defense-related genes in a region of tissue surrounding infection sites and later, with the systemic increase in expression of a number of other genes. Examination of the reactions of individual living cells of potato leaves infected with Phytophthora infestans enabled the comprehensive description of the dynamic aspects of all stages of the defense response. Cytochemical investigations, employing cultured cells of parsley infected with P. infestans as a versatile model system, have contributed to a better understanding of cytoplasmic and metabolic processes occurring during the defense response, and suggest that hypersensitive cell death requires the preceding activation of respiration and specific metabolic pathways. Key words: defense responses, defense-related genes, hypersensitive reaction, programmed cell death.

scholarly journals The Elicitor Protein AsES Induces a Systemic Acquired Resistance Response Accompanied by Systemic Microbursts and Micro–Hypersensitive Responses in Fragaria ananassa

2018 ◽  
Vol 31 (1) ◽  
pp. 46-60 ◽  
Author(s):  
Verónica Hael-Conrad ◽  
Silvia Marisa Perato ◽  
Marta Eugenia Arias ◽  
Martín Gustavo Martínez-Zamora ◽  
Pía de los Ángeles Di Peto ◽  
...  
Keyword(s):  
Cell Death ◽  
Systemic Acquired Resistance ◽  
Calcium Influx ◽  
Wide Spectrum ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Death Process ◽  
Fragaria Ananassa ◽  
Hypersensitive Cell Death ◽  
Acremonium Strictum

The elicitor AsES (Acremonium strictum elicitor subtilisin) is a 34-kDa subtilisin-like protein secreted by the opportunistic fungus Acremonium strictum. AsES activates innate immunity and confers resistance against anthracnose and gray mold diseases in strawberry plants (Fragaria × ananassa Duch.) and the last disease also in Arabidopsis. In the present work, we show that, upon AsES recognition, a cascade of defense responses is activated, including: calcium influx, biphasic oxidative burst (O2⋅− and H2O2), hypersensitive cell-death response (HR), accumulation of autofluorescent compounds, cell-wall reinforcement with callose and lignin deposition, salicylic acid accumulation, and expression of defense-related genes, such as FaPR1, FaPG1, FaMYB30, FaRBOH-D, FaRBOH-F, FaCHI23, and FaFLS. All these responses occurred following a spatial and temporal program, first induced in infiltrated leaflets (local acquired resistance), spreading out to untreated lateral leaflets, and later, to distal leaves (systemic acquired resistance). After AsES treatment, macro-HR and macro–oxidative bursts were localized in infiltrated leaflets, while micro-HRs and microbursts occurred later in untreated leaves, being confined to a single cell or a cluster of a few epidermal cells that differentiated from the surrounding ones. The differentiated cells initiated a time-dependent series of physiological and anatomical changes, evolving to idioblasts accumulating H2O2 and autofluorescent compounds that blast, delivering its content into surrounding cells. This kind of systemic cell-death process in plants is described for the first time in response to a single elicitor. All data presented in this study suggest that AsES has the potential to activate a wide spectrum of biochemical and molecular defense responses in F. ananassa that may explain the induced protection toward pathogens of opposite lifestyle, like hemibiotrophic and necrotrophic fungi.

Dynamic intracellular reorganization of cytoskeletons and the vacuole in defense responses and hypersensitive cell death in plants

2011 ◽  
Vol 124 (3) ◽  
pp. 315-324 ◽  
Author(s):  
Takumi Higaki ◽  
Takamitsu Kurusu ◽  
Seiichiro Hasezawa ◽  
Kazuyuki Kuchitsu
Keyword(s):  
Cell Death ◽  
Defense Responses ◽  
Hypersensitive Cell Death

scholarly journals Identification of Specific Fragments of HpaGXooc, a Harpin from Xanthomonas oryzae pv. oryzicola, that Induce Disease Resistance and Enhance Growth in Plants

2008 ◽  
Vol 98 (7) ◽  
pp. 781-791 ◽  
Author(s):  
Lei Chen ◽  
Jun Qian ◽  
Shuping Qu ◽  
Juying Long ◽  
Qian Yin ◽  
...  
Keyword(s):  
Cell Death ◽  
Disease Resistance ◽  
Amino Acid ◽  
Pathogenic Bacteria ◽  
Magnaporthe Grisea ◽  
Defense Responses ◽  
Xanthomonas Oryzae ◽  
Hypersensitive Cell Death ◽  
Beneficial Effects ◽  
Parent Protein

Harpin proteins from gram-negative plant-pathogenic bacteria can stimulate hypersensitive cell death (HCD) and pathogen defense as well as enhance growth in plants. Two of these diverse activities clearly are beneficial and may depend on particular functional regions of the proteins. Identification of beneficial and deleterious regions might facilitate the beneficial use of harpin-related proteins on crops without causing negative effects like cell death. Here, we report the identification and testing of nine functional fragments of HpaGXooc, a 137-amino-acid harpin protein from Xanthomonas oryzae pv. oryzicola, the pathogen that causes bacterial leaf streak of rice. Polymerase chain reaction-based mutagenesis generated nine proteinaceous fragments of HpaGXooc; these caused different responses following their application to Nicotiana tabacum (tobacco) and Oryza sativa (rice). Fragment HpaG62-137, which spans the indicated amino acid residues of the HpaG, induced more intense HCD; in contrast, HpaG10-42 did not cause evident cell death in tobacco. However, both fragments stimulated stronger defense responses and enhanced more growth in rice than the full-length parent protein, HpaGXooc. Of the nine fragments, the parent protein and one deletion mutant of HpaGXooc tested, HpaG10-42, stimulated higher levels of rice growth and resulted in greater levels of resistance to X. oryzae pv. oryzae and Magnaporthe grisea. These pathogens cause bacterial leaf blight and rice blast, respectively, the two most important diseases of rice world-wide. HpaG10-42 was more active than HpaGXooc in inducing expression of several genes that regulate rice defense and growth processes and activating certain signaling pathways, which may explain the greater beneficial effects observed from treatment with that fragment. Overall, our results suggest that HpaG10-42 holds promise for practical agricultural use to induce disease resistance and enhance growth of rice.

scholarly journals Microtubule Polymerization Functions in Hypersensitive Response and Accumulation of H2O2in Wheat Induced by the Stripe Rust

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Juan Wang ◽  
Yang Wang ◽  
Xinjie Liu ◽  
Yuanliu Xu ◽  
Qing Ma
Keyword(s):  
Cell Death ◽  
Stripe Rust ◽  
Hypersensitive Response ◽  
Puccinia Striiformis ◽  
Rust Fungus ◽  
Defense Responses ◽  
Microtubule Inhibitor ◽  
Hypersensitive Cell Death ◽  
Wheat Leaves ◽  
Plant Cytoskeleton

The plant cytoskeleton, including microtubules and microfilaments, is one of the important factors in determining the polarity of cell division and growth, as well as the interaction of plants with invading pathogens. In defense responses of wheat against the stripe rust (Puccinia striiformisf. sp.tritici) infection, hypersensitive response is the most crucial event to prevent the spread of pathogens. In order to reveal the effect of microtubules on the hypersensitive cell death and H2O2accumulation in the interaction of wheat (Triticum aestivum) cv. Suwon 11 with an incompatible race, CYR23, wheat leaves were treated with microtubule inhibitor, oryzalin, before inoculation. The results showed that the frequency of infection sites with hypersensitive response occurrence was significantly reduced, and hypersensitive cell death in wheat leaves was suppressed compared to the control. In addition, the frequency and the incidence of infected cells with H2O2accumulation were also reduced after the treatment with oryzalin. Those results indicated that microtubules are related to hypersensitive response and H2O2accumulation in wheat induced by the stripe rust, and depolymerization of microtubules reduces the resistance of plants to pathogen infection in incompatible interaction, suggesting that microtubules play a potential role in the expression of resistance of wheat against the stripe rust fungus.

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