scholarly journals SPL36 Encodes a Receptor-like Protein Kinase that Regulates Programmed Cell Death and Defense Responses in Rice

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
R. A. O. Yuchun ◽  
J. I. A. O. Ran ◽  
W. A. N. G. Sheng ◽  
W. U. Xianmei ◽  
Y. E. Hanfei ◽  
...  
Keyword(s):  
Cell Death ◽  
Salt Stress ◽  
Protein Kinase ◽  
Programmed Cell Death ◽  
Stress Responses ◽  
Defense Responses ◽  
Base Substitution ◽  
Wild Type ◽  
Salt Stress Response ◽  
Lesion Mimic

AbstractLesion mimic mutants spontaneously produce disease spots in the absence of biotic or abiotic stresses. Analyzing lesion mimic mutants’ sheds light on the mechanisms underlying programmed cell death and defense-related responses in plants. Here, we isolated and characterized the rice (Oryza sativa) spotted leaf 36 (spl36) mutant, which was identified from an ethyl methanesulfonate-mutagenized japonica cultivar Yundao population. spl36 displayed spontaneous cell death and enhanced resistance to rice bacterial pathogens. Gene expression analysis suggested that spl36 functions in the disease response by upregulating the expression of defense-related genes. Physiological and biochemical experiments indicated that more cell death occurred in spl36 than the wild type and that plant growth and development were affected in this mutant. We isolated SPL36 by map-based cloning. A single base substitution was detected in spl36, which results in a cysteine-to-arginine substitution in SPL36. SPL36 is predicted to encode a receptor-like protein kinase containing leucine-rich domains that may be involved in stress responses in rice. spl36 was more sensitive to salt stress than the wild type, suggesting that SPL36 also negatively regulates the salt-stress response. These findings suggest that SPL36 regulates the disease resistance response in rice by affecting the expression of defense- and stress-related genes.

scholarly journals Proteome Analysis of Programmed Cell Death and Defense Signaling Using the Rice Lesion Mimic Mutant cdr2

2005 ◽  
Vol 18 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Hajime Tsunezuka ◽  
Masayuki Fujiwara ◽  
Tsutomu Kawasaki ◽  
Ko Shimamoto
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Proteome Analysis ◽  
Defense Responses ◽  
Spectrometric Analysis ◽  
Wild Type ◽  
High Accumulation ◽  
Defense Signaling ◽  
Lesion Mimic ◽  
Related Proteins

We have previously identified three lesion-mimic mutants, cell death and resistance (cdr), in rice. These mutants induce a series of defense responses, including expression of defense-related genes and high accumulation of phytoalexins, indicating that the cdr mutants are useful materials to study programmed cell death and defense signaling in rice. Here, we carried out a proteome analysis of the cdr2 mutant. Total proteins prepared from the wild type and the cdr2 mutant at three different stages of lesion formation were compared using two-dimensional electrophoresis. We found a total of 37 proteins that were differentially expressed between cdr2 and wild type. Among them, 28 spots were up-regulated and nine were down-regulated in the cdr2 mutant. All the protein spots were identified by mass spectrometric analysis. These differentially regulated proteins included defense-related proteins. In addition, 27 proteins were classified as metabolic enzymes, suggesting that the programmed cell death that occurs in the cdr2 mutant is associated with active metabolic changes. Our study shows that proteome analysis is a useful approach to study programmed cell death and defense signaling in plants.

scholarly journals Harpin Inactivates Mitochondria in Arabidopsis Suspension Cells

2004 ◽  
Vol 17 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Maren Krause ◽  
Jörg Durner
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Pseudomonas Syringae ◽  
Stress Responses ◽  
Time Course ◽  
Defense Responses ◽  
Ros Generation ◽  
Suspension Cells ◽  
Mitochondrial Functions ◽  
Arabidopsis Cells

Harpin is a well-known proteinaceous bacterial elicitor that can induce an oxidative burst and programmed cell death in various host plants. Given the demonstrated roles of mitochondria in animal apoptosis, we investigated the effect of harpin from Pseudomonas syringae on mitochondrial functions in Arabidopsis suspension cells in detail. Fluorescence microscopy in conjunction with double-staining for reactive oxygen species (ROS) and mitochondria suggested co-localization of mitochondria and ROS generation. Plant defense responses or cell death after pathogen attack have been suggested to be regulated by the concerted action of ROS and nitric oxide (NO). However, although Arabidopsis cells respond to harpin treatment with NO generation, time course analyses suggest that NO generation is not involved in initial responses but, rather, is a consequence of cellular decay. Among the fast responses we observed was a decrease of the mitochondrial membrane potential Δψm and, possibly as a direct consequence, of ATP production. Furthermore, treatment of Arabidopsis cells with harpin protein induced a rapid cytochrome C release from mitochondria into the cytosol, which is regarded as a hallmark of programmed cell death or apoptosis. Northern and DNA array analyses showed strong induction of protecting or scavenging systems such as alternative oxidase and small heat shock proteins, components that are known to be associated with cellular stress responses. In sum, the presented data suggest that harpin inactivates mitochondria in Arabidopsis cells.

scholarly journals Arabidopsis EDR1 Protein Kinase Regulates the Association of EDS1 and PAD4 to Inhibit Cell Death

2020 ◽  
Vol 33 (4) ◽  
pp. 693-703 ◽  
Author(s):  
Matthew Neubauer ◽  
Irene Serrano ◽  
Natalie Rodibaugh ◽  
Deepak D. Bhandari ◽  
Jaqueline Bautor ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Kinase ◽  
Defense Responses ◽  
Loss Of Function ◽  
Wild Type ◽  
Independent Function ◽  
Signaling Function ◽  
Golovinomyces Cichoracearum ◽  
Powdery Mildew Pathogen ◽  
Heteromeric Association

ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and PHYTOALEXIN DEFICIENT4 (PAD4) are sequence-related lipase-like proteins that function as a complex to regulate defense responses in Arabidopsis by both salicylic acid–dependent and independent pathways. Here, we describe a gain-of-function mutation in PAD4 (S135F) that enhances resistance and cell death in response to infection by the powdery mildew pathogen Golovinomyces cichoracearum. The mutant PAD4 protein accumulates to wild-type levels in Arabidopsis cells, thus these phenotypes are unlikely to be due to PAD4 over accumulation. The phenotypes are similar to loss-of-function mutations in the protein kinase EDR1 (Enhanced Disease Resistance1), and previous work has shown that loss of PAD4 or EDS1 suppresses edr1-mediated phenotypes, placing these proteins downstream of EDR1. Here, we show that EDR1 directly associates with EDS1 and PAD4 and inhibits their interaction in yeast and plant cells. We propose a model whereby EDR1 negatively regulates defense responses by interfering with the heteromeric association of EDS1 and PAD4. Our data indicate that the S135F mutation likely alters an EDS1-independent function of PAD4, potentially shedding light on a yet-unknown PAD4 signaling function.

scholarly journals Golgi anti-apoptotic proteins are evolutionarily conserved ion channels that regulate cell death in plants

2019 ◽  
Author(s):  
Maija Sierla ◽  
David L. Prole ◽  
Nuno Saraiva ◽  
Guia Carrara ◽  
Natalia Dinischiotu ◽  
...  
Keyword(s):  
Cell Death ◽  
Ion Channels ◽  
Programmed Cell Death ◽  
Stress Responses ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Lesion Mimic ◽  
Evolutionarily Conserved ◽  
Apoptotic Proteins ◽  
Regulate Cell Death

ABSTRACTProgrammed cell death regulates developmental and stress responses in eukaryotes. Golgi anti-apoptotic proteins (GAAPs) are evolutionarily conserved cell death regulators. Human and viral GAAPs inhibit apoptosis and modulate intracellular Ca2+fluxes, and viral GAAPs form cation-selective channels. Although most mammalian cell death regulators are not conserved at the sequence level in plants, the GAAP gene family shows expansion, with five paralogues (AtGAAP1-5) in the Arabidopsis genome. We pursued molecular and physiological characterization of AtGAAPs making use of the advanced knowledge of their human and viral counterparts. Structural modeling of AtGAAPs predicted the presence of a channel-like pore, and electrophysiological recordings from purified AtGAAP3 reconstituted into lipid bilayers confirmed that plant GAAPs can function as ion channels. AtGAAP1 and AtGAAP4 localized exclusively to the Golgi within the plant cell, while AtGAAP2, AtGAAP3 and AtGAAP5 also showed tonoplastic localization. Gene expression analysis revealed differential spatial expression and abundance of transcript forAtGAAPparalogues in Arabidopsis tissues. We demonstrate that AtGAAP1-5 inhibit Bax-induced cell death in yeast. However, overexpression of AtGAAP1 induces cell death inNicotiana benthamianaleaves and lesion mimic phenotype in Arabidopsis. We propose that AtGAAPs function as Golgi-localized ion channels that regulate cell death by affecting ionic homeostasis within the cell.HighlightArabidopsis Golgi anti-apoptotic proteins (GAAPs) share functional conservation with their human and viral counterparts in cell death regulation and ion channel activityAbbreviationsAtGAAP,Arabidopsis thalianaGAAP; BI-1, Bax inhibitor-1; CFP, cyan fluorescent protein; CMLV, camelpox virus; ER, Endoplasmic reticulum; GAAP, Golgi anti-apoptotic protein; GFP, green fluorescent protein; hGAAP, human GAAP; LFG, Lifeguard; LMM, lesion mimic mutant; PCD, programmed cell death; TMBIM, transmembrane Bax inhibitor-1 motif-containing; TMDs, transmembrane domains; vGAAP, viral GAAP; YFP, yellow fluorescent protein

scholarly journals Stress-Activated Protein Kinase OsSAPK9 Regulates Tolerance to Salt Stress and Resistance to Bacterial Blight in Rice

Rice ◽  
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Fan Zhang ◽  
Dan Zeng ◽  
Liyu Huang ◽  
Yingyao Shi ◽  
Tengjun Chen ◽  
...  
Keyword(s):  
Salt Stress ◽  
Disease Resistance ◽  
Protein Kinase ◽  
Stress Responses ◽  
Bacterial Blight ◽  
Molecular Mechanisms ◽  
Defense Responses ◽  
Stress Conditions ◽  
Differentially Expressed ◽  
Limiting Factors

Abstract Background Salt stress and bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) are key limiting factors of rice (Oryza sativa L.) yields. Members of sucrose non-fermenting 1 (SNF1)-related protein kinase 2 (SnRK2), which is a family of plant-specific Ser/Thr kinases, are important components of signaling pathways involved in plant developmental processes and responses to stresses. There are 10 members of the SnRK2 family in rice; however, their functions are poorly understood, as are the underlying molecular mechanisms. Results In this study, we found that OsSAPK9, which belongs to the SnRK2 family, positively regulated salt-stress tolerance and strain-specific resistance to bacterial blight in rice. RNA sequencing revealed that there were 404 and 1324 genes differentially expressed in OsSAPK9-RNAi in comparison with wild-type plants under salt-stress conditions and after Xoo inoculation, respectively, which participate in basic metabolic processes. In total, 65 common differentially expressed genes involved mainly in defense responses were detected both under salt-stress conditions and after Xoo inoculation. Moreover, in vivo and in vitro experiments demonstrated that OsSAPK9 forms a protein complex with the molecular chaperones OsSGT1 and OsHsp90, and transgenic plants overexpressing OsSGT1 exhibited decreased tolerances to salt stress and significantly increased resistance levels to bacterial blight. Thus, OsSAPK9 may function as a center node regulator of salt-stress responses and disease-resistance pathways through its interaction with OsSGT1 in rice. Conclusion This study confirms that OsSAPK9 functions as a positive regulator of salt-stress responses and disease resistance through its interaction with OsSGT1 in rice.

scholarly journals OsPG1 encodes a polygalacturonase that determines cell wall architecture and affects resistance to bacterial blight pathogen in rice

2021 ◽  
Author(s):  
Yongrun Cao ◽  
Yue Zhang ◽  
Yuyu Chen ◽  
Ning Yu ◽  
Shah Liaqat ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Wall ◽  
Defense Response ◽  
Cell Walls ◽  
Bacterial Blight ◽  
Defense Responses ◽  
Base Substitution ◽  
Loss Of Function ◽  
Wild Type ◽  
Bacterial Blight Pathogen

Abstract Background: Plant cell walls are the main physical barrier encountered by pathogens colonizing plant tissues. Alteration of cell wall integrity (CWI) can activate specific defenses by impairing proteins involved in cell wall biosynthesis, degradation and remodeling, or cell wall damage due to biotic or abiotic stress. Polygalacturonase (PG) depolymerize pectin by hydrolysis, thereby altering pectin composition and structures and activating cell wall defense. Although many studies of CWI have been reported, the mechanism of how PGs regulate cell wall immune response is not well understood. Results: Necrosis appeared in leaf tips at the tillering stage, finally resulting in 3-5 cm of dark brown necrotic tissue. ltn-212 showed obvious cell death and accumulation of H2O2 in leaf tips. The defense responses were activated in ltn-212 to resist bacterial blight pathogen of rice. Map based cloning revealed that a single base substitution (G-A) in the first intron caused incorrect splicing of OsPG1, resulting in a necrotic phenotype. OsPG1 is constitutively expressed in all organs, and the wild-type phenotype was restored in complementation individuals and knockout of wild-type lines resulted in necrosis as in ltn-212. Transmission electron microscopy showed that thicknesses of cell walls were significantly reduced and cell size and shape were significantly diminished in ltn-212.Conclusion: These results demonstrate that OsPG1 encodes a PG in response to the leaf tip necrosis phenotype of ltn-212. Loss-of-function mutation of ltn-212 destroyed CWI, resulting in spontaneous cell death and an auto-activated defense response including reactive oxygen species (ROS) burst and pathogenesis-related (PR) gene expression, as well as enhanced resistance to Xanthomonas oryzae pv. oryzae (Xoo). These findings promote our understanding of the CWI mediated defense response.

scholarly journals OsPG1 encodes a polygalacturonase that determines cell wall architecture and affects resistance to bacterial blight pathogen in rice

2020 ◽  
Author(s):  
Qunen Liu ◽  
Yongrun Cao ◽  
Yue Zhang ◽  
Yuyu Chen ◽  
Ning Yu ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Wall ◽  
Defense Response ◽  
Cell Walls ◽  
Bacterial Blight ◽  
Defense Responses ◽  
Base Substitution ◽  
Loss Of Function ◽  
Wild Type ◽  
Bacterial Blight Pathogen

Abstract Background Plant cell walls are the main physical barrier encountered by pathogens colonizing plant tissues. Alteration of cell wall integrity (CWI) can activate specific defenses by impairing proteins involved in cell wall biosynthesis, degradation and remodeling, or cell wall damage due to biotic or abiotic stress. Polygalacturonase (PG) depolymerize pectin by hydrolysis, thereby altering pectin composition and structures and activating cell wall defense. Although many studies of CWI have been reported, the mechanism of how PGs regulate cell wall immune response is not well understood.Results Necrosis appeared in leaf tips at the tillering stage, finally resulting in 3–5 cm of dark brown necrotic tissue. ltn-212 showed obvious cell death and accumulation of H2O2 in leaf tips. The defense responses were activated in ltn-212 to resist bacterial blight pathogen of rice. Map based cloning revealed that a single base substitution (G-A) in the first intron caused incorrect splicing of OsPG1, resulting in a necrotic phenotype. OsPG1 is constitutively expressed in all organs, and the wild-type phenotype was restored in complementation individuals and knockout of wild-type lines resulted in necrosis as in ltn-212. Transmission electron microscopy showed that thicknesses of cell walls were significantly reduced and cell size and shape were significantly diminished in ltn-212.Conclusion These results demonstrate that OsPG1 encodes a PG in response to the leaf tip necrosis phenotype of ltn-212. Loss-of-function mutation of ltn-212 destroyed CWI, resulting in spontaneous cell death and an auto-activated defense response including reactive oxygen species (ROS) burst and pathogenesis-related (PR) gene expression, as well as enhanced resistance to Xanthomonas oryzae pv. oryzae (Xoo). These findings promote our understanding of the CWI mediated defense response.

scholarly journals Disruption of OsPHD1, Encoding a UDP-Glucose Epimerase, Causes JA Accumulation and Enhanced Bacterial Blight Resistance in Rice

2022 ◽  
Vol 23 (2) ◽  
pp. 751
Author(s):  
Yu Gao ◽  
Xiaojiao Xiang ◽  
Yingxin Zhang ◽  
Yongrun Cao ◽  
Beifang Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
Defense Response ◽  
Bacterial Blight ◽  
Defense Responses ◽  
Wild Type ◽  
Causal Gene ◽  
Physiological Mechanisms ◽  
Lesion Mimic ◽  
Cloning Strategy ◽  
Ja Signaling

Lesion mimic mutants (LMMs) have been widely used in experiments in recent years for studying plant physiological mechanisms underlying programmed cell death (PCD) and defense responses. Here, we identified a lesion mimic mutant, lm212-1, which cloned the causal gene by a map-based cloning strategy, and verified this by complementation. The causal gene, OsPHD1, encodes a UDP-glucose epimerase (UGE), and the OsPHD1 was located in the chloroplast. OsPHD1 was constitutively expressed in all organs, with higher expression in leaves and other green tissues. lm212-1 exhibited decreased chlorophyll content, and the chloroplast structure was destroyed. Histochemistry results indicated that H2O2 is highly accumulated and cell death is occurred around the lesions in lm212-1. Compared to the wild type, expression levels of defense-related genes were up-regulated, and resistance to bacterial pathogens Xanthomonas oryzae pv. oryzae (Xoo) was enhanced, indicating that the defense response was activated in lm212-1, ROS production was induced by flg22, and chitin treatment also showed the same result. Jasmonic acid (JA) and methyl jasmonate (MeJA) increased, and the JA signaling pathways appeared to be disordered in lm212-1. Additionally, the overexpression lines showed the same phenotype as the wild type. Overall, our findings demonstrate that OsPHD1 is involved in the regulation of PCD and defense response in rice.

scholarly journals Arabidopsis ENHANCED DISEASE RESISTANCE1 Protein Kinase Regulates the Association of ENHANCED DISEASE SUSCEPTIBILITY1 and PHYTOALEXIN DEFICIENT4 to Inhibit Cell Death

2019 ◽  
Author(s):  
Matthew Neubauer ◽  
Irene Serrano ◽  
Natalie Rodibaugh ◽  
Deepak D. Bhandari ◽  
Jaqueline Bautor ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Kinase ◽  
Defense Responses ◽  
Loss Of Function ◽  
Wild Type ◽  
Independent Function ◽  
Signaling Function ◽  
Golovinomyces Cichoracearum ◽  
Powdery Mildew Pathogen ◽  
Heteromeric Association

ABSTRACTENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and PHYTOALEXIN DEFICIENT4 (PAD4) are sequence-related lipase-like proteins that function as a complex to regulate defense responses in Arabidopsis by both salicylic acid-dependent and independent pathways. Here we describe a gain-of-function mutation in PAD4 (S135F) that enhances resistance and cell death in response to infection by the powdery mildew pathogen Golovinomyces cichoracearum. The mutant PAD4 protein accumulates to wild-type levels in Arabidopsis cells, thus these phenotypes are unlikely to be due to PAD4 over accumulation. The phenotypes are similar to loss of function mutations in the protein kinase Enhanced Disease Resistance1 (EDR1), and previous work has shown that loss of PAD4 or EDS1 suppresses edr1-mediated phenotypes, placing these proteins downstream of EDR1. Here we show that EDR1 directly associates with EDS1 and PAD4 and inhibits their interaction in yeast and plant cells. We propose a model whereby EDR1 negatively regulates defense responses by interfering with the heteromeric association of EDS1 and PAD4. Our data indicate that the S135F mutation likely alters an EDS1-independent function of PAD4, potentially shedding light on a yet unknown PAD4 signaling function.

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