Ethylene-Mediated Programmed Cell Death during Maize Endosperm Development of Wild-Type and shrunken2 Genotypes

The normal developmental sequence in a grass grain entails the death of several maternal and filial tissues in a genetically regulated process termed programmed cell death (PCD). The progression and molecular aspects of PCD in developing grains have been reported for domesticated species such as barley, rice, maize and wheat. Here, we report a detailed investigation of PCD in the developing grain of the wild model species Brachypodium distachyon. We detected PCD in developing Brachypodium grains using molecular and histological approaches. We also identified in Brachypodium the orthologs of protease genes known to contribute to grain PCD and surveyed their expression. We found that, similar to cereals, PCD in the Brachypodium nucellus occurs in a centrifugal pattern following anthesis. However, compared to cereals, the rate of post-mortem clearance in the Brachypodium nucellus is slower. However, compared to wheat and barley, mesocarp PCD in Brachypodium proceeds more rapidly in lateral cells. Remarkably, Brachypodium mesocarp PCD is not coordinated with endosperm development. Phylogenetic analysis suggests that barley and wheat possess more vacuolar processing enzymes that drive nucellar PCD compared to Brachypodium and rice. Our expression analysis highlighted putative grain-specific PCD proteases in Brachypodium. Combined with existing knowledge on grain PCD, our study suggests that the rate of nucellar PCD moderates grain size and that the pattern of mesocarp PCD influences grain shape.

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Lack ofHXK2Induces Localization of Active Ras in Mitochondria and Triggers Apoptosis in the YeastSaccharomyces cerevisiae

Oxidative Medicine and Cellular Longevity ◽

10.1155/2013/678473 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 23

Author(s):

Loredana Amigoni ◽

Enzo Martegani ◽

Sonia Colombo

Keyword(s):

Cell Death ◽

Acetic Acid ◽

Plasma Membrane ◽

Programmed Cell Death ◽

Mitochondrial Dysfunction ◽

Type Strain ◽

Wild Type Strain ◽

Ros Production ◽

Ras Proteins ◽

Wild Type

We recently showed that activated Ras proteins are localized to the plasma membrane and in the nucleus in wild-type cells growing exponentially on glucose, while in thehxk2Δ strain they accumulated mainly in mitochondria. An aberrant accumulation of activated Ras in these organelles was previously reported and correlated to mitochondrial dysfunction, accumulation of ROS, and cell death. Here we show that addition of acetic acid to wild-type cells results in a rapid recruitment of Ras-GTP from the nucleus and the plasma membrane to the mitochondria, providing a further proof that Ras proteins might be involved in programmed cell death. Moreover, we show that Hxk2 protects against apoptosis inS. cerevisiae. In particular, cells lackingHXK2and showing a constitutive accumulation of activated Ras at the mitochondria are more sensitive to acetic-acid-induced programmed cell death compared to the wild type strain. Indeed, deletion ofHXK2causes an increase of apoptotic cells with several morphological and biochemical changes that are typical of apoptosis, including DNA fragmentation, externalization of phosphatidylserine, and ROS production. Finally, our results suggest that apoptosis induced by lack of Hxk2 may not require the activation of Yca1, the metacaspase homologue identified in yeast.

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Starch Synthesis and Programmed Cell Death during endosperm Development in Triticale (×Triticosecale Wittmack)

Journal of Integrative Plant Biology ◽

10.1111/j.1744-7909.2010.00961.x ◽

2010 ◽

pp. no-no

Author(s):

Chun-Yan Li ◽

Wei-Hua Li ◽

Cheng Li ◽

Denis A. Gaudet ◽

André Laroche ◽

...

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Starch Synthesis ◽

Endosperm Development ◽

Triticosecale Wittmack

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Old Yellow Enzymes, Highly Homologous FMN Oxidoreductases with Modulating Roles in Oxidative Stress and Programmed Cell Death in Yeast

Journal of Biological Chemistry ◽

10.1074/jbc.m704058200 ◽

2007 ◽

Vol 282 (49) ◽

pp. 36010-36023 ◽

Cited By ~ 43

Author(s):

Osama Odat ◽

Samer Matta ◽

Hadi Khalil ◽

Sotirios C. Kampranis ◽

Raymond Pfau ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Death ◽

Programmed Cell Death ◽

Antioxidant Activities ◽

Ros Generation ◽

Oxidized Glutathione ◽

Wild Type ◽

Antioxidant Genes ◽

Knock Out ◽

Chronological Aging

In a genetic screen to identify modifiers of Bax-dependent lethality in yeast, the C terminus of OYE2 was isolated based on its capacity to restore sensitivity to a Bax-resistant yeast mutant strain. Overexpression of full-length OYE2 suppresses Bax lethality in yeast, lowers endogenous reactive oxygen species (ROS), increases resistance to H2O2-induced programmed cell death (PCD), and significantly lowers ROS levels generated by organic prooxidants. Reciprocally, Δoye2 yeast strains are sensitive to prooxidant-induced PCD. Overexpression and knock-out analysis indicate these OYE2 antioxidant activities are opposed by OYE3, a highly homologous heterodimerizing protein, which functions as a prooxidant promoting H2O2-induced PCD in wild type yeast. To exert its effect OYE3 requires the presence of OYE2. Deletion of the 12 C-terminal amino acids and catalytic inactivation of OYE2 by a Y197F mutation enhance significantly survival upon H2O2-induced PCD in wild type cells, but accelerate PCD in Δoye3 cells, implicating the oye2p-oye3p heterodimer for promoting cell death upon oxidative stress. Unexpectedly, a strain with a double knock-out of these genes (Δoye2 oye3) is highly resistant to H2O2-induced PCD, exhibits increased respiratory capacity, and undergoes less cell death during the adaptive response in chronological aging. Simultaneous deletion of OYE2 and other antioxidant genes hyperinduces endogenous levels of ROS, promoting H2O2-induced cell death: in Δoye2 glr1 yeast high levels of oxidized glutathione elicited gross morphological aberrations involving the actin cytoskeleton and defects in organelle partitioning. Altering the ratio of reduced to oxidized glutathione by exogenous addition of GSH fully reversed these alterations. Based on this work, OYE proteins are firmly placed in the signaling network connecting ROS generation, PCD modulation, and cytoskeletal dynamics in yeast.

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

Rice ◽

10.1186/s12284-021-00475-y ◽

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.

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Programmed Cell Death in the Developing Brachypodium distachyon Grain

10.1101/775833 ◽

2019 ◽

Author(s):

Safia Saada ◽

Charles Ugochukwu Solomon ◽

Sinéad Drea

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Grain Shape ◽

Brachypodium Distachyon ◽

Endosperm Development ◽

List Type ◽

Developmental Sequence ◽

Model Species ◽

Processing Enzymes ◽

Molecular Aspects

SummaryThe normal developmental sequence in a grass grain entails the death of several maternal and filial tissues in a genetically regulated process termed programmed cell death (PCD). The progression and molecular aspects of PCD in developing grain have been reported for domesticated species like barley, rice, maize and wheat. Here, we report a detailed investigation of PCD in the developing grain of a wild model species, Brachypodium distachyon.We detected PCD in developing Brachypodium grains using molecular and histological approaches. We also identified and surveyed the expression of Brachypodium orthologs of protease genes known to contribute to grain PCD.We found that Brachypodium nucellus degenerates by PCD in a centrifugal pattern following anthesis, although at a slower rate compared to cultivated cereals. Mesocarp PCD was not coordinated with endosperm development. Brachypodium lacks an expansion of vacuolar processing enzymes known for their roles in nucellar PCD.Combined with existing knowledge on grain PCD, our study suggests the importance of rapid nucellar PCD for grain size and that the pattern of mesocarp PCD affects grain shape.

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Clustered gamma-protocadherins regulate cortical interneuron programmed cell death

eLife ◽

10.7554/elife.55374 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 4

Author(s):

Walter R Mancia Leon ◽

Julien Spatazza ◽

Benjamin Rakela ◽

Ankita Chatterjee ◽

Viraj Pande ◽

...

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Critical Role ◽

Morphological Properties ◽

Inhibitory Interneurons ◽

Wild Type ◽

Cortical Function ◽

Cortical Interneuron ◽

Dependent Cell

Cortical function critically depends on inhibitory/excitatory balance. Cortical inhibitory interneurons (cINs) are born in the ventral forebrain and migrate into cortex, where their numbers are adjusted by programmed cell death. Here, we show that loss of clustered gamma protocadherins (Pcdhg), but not of genes in the alpha or beta clusters, increased dramatically cIN BAX-dependent cell death in mice. Surprisingly, electrophysiological and morphological properties of Pcdhg-deficient and wild-type cINs during the period of cIN cell death were indistinguishable. Co-transplantation of wild-type with Pcdhg-deficient interneuron precursors further reduced mutant cIN survival, but the proportion of mutant and wild-type cells undergoing cell death was not affected by their density. Transplantation also allowed us to test for the contribution of Pcdhg isoforms to the regulation of cIN cell death. We conclude that Pcdhg, specifically Pcdhgc3, Pcdhgc4, and Pcdhgc5, play a critical role in regulating cIN survival during the endogenous period of programmed cIN death.

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Wild-Type Herpes Simplex Virus 1 Blocks Programmed Cell Death and Release of Cytochrome c but Not the Translocation of Mitochondrial Apoptosis-Inducing Factor to the Nuclei of Human Embryonic Lung Fibroblasts

Journal of Virology ◽

10.1128/jvi.74.19.9048-9053.2000 ◽

2000 ◽

Vol 74 (19) ◽

pp. 9048-9053 ◽

Cited By ~ 26

Author(s):

Guoying Zhou ◽

Bernard Roizman

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Infected Cell ◽

Wild Type Virus ◽

Type Virus ◽

Wild Type ◽

Human Embryonic Lung ◽

Herpes Simplex Virus 1 ◽

Infected Cells ◽

In Cells

ABSTRACT Programmed cell death activated by herpes simplex virus 1 mutants can be caspase dependent or independent depending on the nature of the infected cell. The recently discovered mitochondrial apoptosis-inducing factor (AIF) on activation is translocated to the nucleus and induces programmed cell death that is caspase independent. To assess the role of AIF and also to assay apoptosis-related events in primary human embryonic lung (HEL) fibroblasts, cells were mock infected or infected with wild-type virus previously shown not to induce apoptosis in continuous lines of primate cells or with the d120 mutant lacking infected cell protein no. 4 (ICP4) and were shown to induce apoptosis in all cell lines tested. Cells exposed to dexamethasone or osmotic shock induced by sorbitol were the positive controls. The results were as follows: (i) AIF was translocated to the nucleus in all infected cell cultures and in cells treated with dexamethasone or sorbitol, but cells infected with the wild type-virus showed no evidence of undergoing programmed death. (ii) Cytochrome cwas released from mitochondria of cells infected with thed120 mutant or exposed to dexamethasone or sorbitol but not from mitochondria in cells treated with sorbitol and infected with the wild-type virus. (iii) Poly(ADP-ribose) polymerase was cleaved in mock-infected cells exposed to sorbitol or dexamethasone and in cells infected with the d120 mutant but not in either untreated cells infected with wild-type virus or cells exposed to sorbitol and then infected with wild-type virus. In contrast to HEp-2 cells, neitherd120 infection nor treatment with dexamethasone or sorbitol caused fragmentation of DNA in HEL fibroblasts. Electron microscopic examination showed chromatin condensation and vacuolization in a fraction of cells infected with d120 but not in wild-type virus-infected cells or cells treated with dexamethasone or sorbitol. We conclude that AIF is translocated to the nucleus in infected cells but apoptosis does not ensue in wild-type-infected cells. HEL fibroblasts infected with the d120 virus exhibit symptoms of classical apoptosis, such as cytochrome c release and cleavage of poly(ADP-ribose) polymerase observed also in cells undergoing caspase 3-dependent programmed cell death in which AIF is either not involved or not a contributory factor.

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