Overexpression of OsMed16 Inhibits the Growth of Rice and Causes Spontaneous Cell Death

The Mediator complex transduces information from the DNA-bound transcription factors to the RNA polymerase II transcriptional machinery. Research on plant Mediator subunits has primarily been performed in Arabidopsis, while very few of them have been functionally characterized in rice. In this study, the rice Mediator subunit 16, OsMed16, was examined. OsMed16 encodes a putative protein of 1301 amino acids, which is longer than the version previously reported. It was expressed in various rice organs and localized to the nucleus. The knockout of OsMed16 resulted in rice seedling lethality. Its overexpression led to the retardation of rice growth, low yield, and spontaneous cell death in the leaf blade and sheath. RNA sequencing suggested that the overexpression of OsMed16 altered the expression of a large number of genes. Among them, the upregulation of some defense-related genes was verified. OsMed16 can regulate the expression of a wealth of genes, and alterations in its expression have a profound impact on plant growth, development, and defense responses in rice.

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Overexpression of OsMed16 inhibits rice growth and causes spontaneous cell death

10.21203/rs.3.rs-66827/v1 ◽

2020 ◽

Author(s):

Jie Jiang ◽

Guangzhe Yang ◽

Yafeng Xin ◽

Zhigang Wang ◽

Wei Yan ◽

...

Keyword(s):

Cell Death ◽

Rna Polymerase Ii ◽

Leaf Blade ◽

Leaf Sheath ◽

Rice Seedling ◽

Putative Protein ◽

Rice Growth ◽

Number Of Genes ◽

Growth Development ◽

Spontaneous Cell Death

Abstract Background The Mediator complex transduces information from the DNA-bound transcription factors to the RNA polymerase II transcriptional machinery. Research on plant Mediator subunits was mainly performed in Arabidopsis, while very few of them have been functionally characterized in rice. Results Here the rice Mediator subunit 16, OsMed16, was studied. OsMed16 encoded a putative protein of 1301 amino acids, which is longer than the reported version. It was expressed in various rice organs, and localized in nucleus. Knockout of OsMed16 caused rice seedling lethality. Its overexpression led to rice growth retardation, low yield, and spontaneous cell death in leaf blade and leaf sheath. RNA sequencing suggested that overexpression of OsMed16 altered the expression of a large number of genes. Among them, the up-regulation of some defense-related genes was verified. Conclusions Our results demonstrated that OsMed16 can regulate the expression of a wealth of genes, and alterations in its expression have profound impact on plant growth, development and defense response in rice.

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Faculty Opinions recommendation of Nitrate efflux is an essential component of the cryptogein signaling pathway leading to defense responses and hypersensitive cell death in tobacco.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1011782.182572 ◽

2003 ◽

Author(s):

Eric Lam

Keyword(s):

Cell Death ◽

Signaling Pathway ◽

Defense Responses ◽

Hypersensitive Cell Death ◽

Essential Component

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Faculty Opinions recommendation of Cell death and immunity in cancer: From danger signals to mimicry of pathogen defense responses.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.732002205.793538244 ◽

2017 ◽

Author(s):

D John Doyle

Keyword(s):

Cell Death ◽

Defense Responses ◽

Pathogen Defense ◽

Danger Signals

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Overexpression of Pto Induces a Salicylate-Independent Cell Death But Inhibits Necrotic Lesions Caused by Salicylate-Deficiency in Tomato Plants

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2002.15.7.654 ◽

2002 ◽

Vol 15 (7) ◽

pp. 654-661 ◽

Cited By ~ 16

Author(s):

Jianxiong Li ◽

Libo Shan ◽

Jian-Min Zhou ◽

Xiaoyan Tang

Keyword(s):

Cell Death ◽

Disease Resistance ◽

Pseudomonas Syringae ◽

Virulent Strain ◽

Gene Activation ◽

Cellular Damage ◽

Minor Role ◽

Disease Resistance Gene ◽

Tomato Plants ◽

Spontaneous Cell Death

Tomato plants overexpressing the disease resistance gene Pto (35S∷Pto) exhibit spontaneous cell death, accumulation of salicylic acid (SA), elevated expression of pathogenesis-related genes, and enhanced resistance to a broad range of pathogens. Because salicylate plays an important role in the cell death and defense activation in many lesion mimic mutants, we investigated the interaction of SA-mediated processes and the 35S∷Pto-mediated defense pathway by introducing the nahG transgene that encodes salicylate hydroxylase. Here, we show that SA is not required for the 35S∷Pto-activated microscopic cell death and plays a minor role in defense gene activation and general disease resistance in 35S∷Pto plants. In contrast, temperature greatly affects the spontaneous cell death and general resistance in 35S∷Pto plants, and high temperature inhibits the cell death. The NahG tomato plants develop spontaneous, unconstrained necrotic lesions on leaves. These lesions also are initiated by the inoculation of a virulent strain of Pseudomonas syringae pv. tomato. However, the NahG-dependent necrotic lesions are inhibited in the NahG/35S∷Pto plants. This inhibition is most pronounced under conditions favoring the 35S∷Pto-mediated spontaneous cell death development. These results indicate that the signaling pathways activated by Pto overexpression suppress the cellular damage that is caused by SA depletion. We also found that ethylene is dispensable for the 35S∷Pto-mediated general defense.

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Cell Death Triggered by a Putative Amphipathic Helix of Radish mosaic virus Helicase Protein Is Tightly Correlated With Host Membrane Modification

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-01-15-0004-r ◽

2015 ◽

Vol 28 (6) ◽

pp. 675-688 ◽

Cited By ~ 15

Author(s):

Masayoshi Hashimoto ◽

Ken Komatsu ◽

Ryo Iwai ◽

Takuya Keima ◽

Kensaku Maejima ◽

...

Keyword(s):

Cell Death ◽

Mosaic Virus ◽

Defense Responses ◽

Plant Viruses ◽

Amphipathic Helix ◽

Membrane Structures ◽

Membrane Modification ◽

Systemic Necrosis ◽

Amino Terminal ◽

Er Membrane

Systemic necrosis is one of the most severe symptoms caused by plant RNA viruses. Recently, systemic necrosis has been suggested to have similar features to a defense response referred to as the hypersensitive response (HR), a form of programmed cell death. In virus-infected plant cells, host intracellular membrane structures are changed dramatically for more efficient viral replication. However, little is known about whether this replication-associated membrane modification is the cause of the symptoms. In this study, we identified an amino-terminal amphipathic helix of the helicase encoded by Radish mosaic virus (RaMV) (genus Comovirus) as an elicitor of cell death in RaMV-infected plants. Cell death caused by the amphipathic helix had features similar to HR, such as SGT1-dependence. Mutational analyses and inhibitor assays using cerulenin demonstrated that the amphipathic helix–induced cell death was tightly correlated with dramatic alterations in endoplasmic reticulum (ER) membrane structures. Furthermore, the cell death–inducing activity of the amphipathic helix was conserved in Cowpea mosaic virus (genus Comovirus) and Tobacco ringspot virus (genus Nepovirus), both of which are classified in the family Secoviridae. Together, these results indicate that ER membrane modification associated with viral intracellular replication may be recognized to prime defense responses against plant viruses.

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ArabidopsisHSP90 protein modulates RPP4-mediated temperature-dependent cell death and defense responses

New Phytologist ◽

10.1111/nph.12760 ◽

2014 ◽

Vol 202 (4) ◽

pp. 1320-1334 ◽

Cited By ~ 28

Author(s):

Fei Bao ◽

Xiaozhen Huang ◽

Chipan Zhu ◽

Xiaoyan Zhang ◽

Xin Li ◽

...

Keyword(s):

Cell Death ◽

Defense Responses ◽

Temperature Dependent ◽

Dependent Cell

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GLYCINE-RICH RNA-BINDING PROTEIN1 interacts with RECEPTOR-LIKE CYTOPLASMIC PROTEIN KINASE1 and suppresses cell death and defense responses in pepper (Capsicum annuum)

New Phytologist ◽

10.1111/nph.13105 ◽

2014 ◽

Vol 205 (2) ◽

pp. 786-800 ◽

Cited By ~ 8

Author(s):

Dae Sung Kim ◽

Nak Hyun Kim ◽

Byung Kook Hwang

Keyword(s):

Cell Death ◽

Capsicum Annuum ◽

Rna Binding ◽

Defense Responses ◽

Cytoplasmic Protein

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Restoration of Defective Cross Talk in ssi2 Mutants: Role of Salicylic Acid, Jasmonic Acid, and Fatty Acids in SSI2-Mediated Signaling

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2003.16.11.1022 ◽

2003 ◽

Vol 16 (11) ◽

pp. 1022-1029 ◽

Cited By ~ 42

Author(s):

Pradeep Kachroo ◽

Aardra Kachroo ◽

Ludmila Lapchyk ◽

David Hildebrand ◽

Daniel F. Klessig

Keyword(s):

Cell Death ◽

Salicylic Acid ◽

Jasmonic Acid ◽

Cross Talk ◽

Pr Genes ◽

Exogenous Application ◽

Basal Level Expression ◽

Sa Signaling ◽

Spontaneous Cell Death

The Arabidopsis mutants ssi2 and fab2 are defective in stearoyl ACP desaturase, which causes altered salicylic acid (SA)- and jasmonic acid (JA)-mediated defense signaling. Both ssi2 and fab2 plants show spontaneous cell death, express PR genes constitutively, accumulate high levels of SA, and exhibit enhanced resistance to bacterial and oomycete pathogens. In contrast to constitutive activation of the SA pathway, ssi2 and fab2 plants are repressed in JA-mediated induction of the PDF1.2 gene, which suggests that the SSI2-mediated signaling pathway modulates cross talk between the SA and JA pathways. In this study, we have characterized two recessive nonallelic mutants in the ssi2 background, designated as rdc (restorer of defective cross talk) 2 and rdc8. Both ssi2 rdc mutants are suppressed in constitutive SA signaling, show basal level expression of PR-1 gene, and induce high levels of PDF1.2 in response to exogenous application of JA. Interestingly, while the rdc8 mutation completely abolishes spontaneous cell death in ssi2 rdc8 plants, the ssi2 rdc2 plants continue to show some albeit reduced cell death. Fatty acid (FA) analysis showed a reduction in 16:3 levels in ssi2 rdc8 plants, which suggests that this mutation may limit the flux of FAs into the pro-karyotic pathway of glycerolipid biosynthesis. Both rdc2 and rdc8 continue to accumulate high levels of 18:0, which suggests that 18:0 levels were responsible for neither constitutive SA signaling nor repression of JA-induced expression of the PDF1.2 gene in ssi2 plants. We also analyzed SA and JA responses of the fab2-derived shs1 mutant, which accumulates levels of 18:0 over 50% lower than those in the fab2 plants. Even though fab2 shs1 plants were morphologically bigger than fab2 plants, they expressed PR genes constitutively, showed HR-like cell death, and accumulated elevated levels of SA. However, unlike the ssi2 rdc plants, fab2 shs1 plants were unable to induce high levels of PDF1.2 expression in response to exogenous application of JA. Together, these results show that defective cross talk in ssi2 can be restored by second site mutations and is independent of morphological size of the plants, cell death, and elevated levels of 18:0.

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BAX INHIBITOR-1 Is Required for Full Susceptibility of Barley to Powdery Mildew

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-23-9-1217 ◽

2010 ◽

Vol 23 (9) ◽

pp. 1217-1227 ◽

Cited By ~ 58

Author(s):

Ruth Eichmann ◽

Melanie Bischof ◽

Corina Weis ◽

Jane Shaw ◽

Christophe Lacomme ◽

...

Keyword(s):

Cell Death ◽

Powdery Mildew ◽

Gene Silencing ◽

Defense Responses ◽

Negative Control ◽

Cellular Level ◽

Virus Induced Gene Silencing ◽

Powdery Mildew Fungus ◽

Basal Resistance ◽

Enhanced Resistance

BAX INHIBITOR-1 (BI-1) is one of the few proteins known to have cross-kingdom conserved functions in negative control of programmed cell death. Additionally, barley BI-1 (HvBI-1) suppresses defense responses and basal resistance to the powdery mildew fungus Blumeria graminis f. sp. hordei and enhances resistance to cell death–provoking fungi when overexpressed in barley. Downregulation of HvBI-1 by transient-induced gene silencing or virus-induced gene silencing limited susceptibility to B. graminis f. sp. hordei, suggesting that HvBI-1 is a susceptibility factor toward powdery mildew. Transient silencing of BI-1 did not limit supersusceptibility induced by overexpression of MLO. Transgenic barley plants harboring an HvBI-1 RNA interference (RNAi) construct displayed lower levels of HvBI-1 transcripts and were less susceptible to powdery mildew than wild-type plants. At the cellular level, HvBI-1 RNAi plants had enhanced resistance to penetration by B. graminis f. sp. hordei. These data support a function of BI-1 in modulating cell-wall-associated defense and in establishing full compatibility of B. graminis f. sp. hordei with barley.

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