Inducible cell death in plant immunity. Semin Cancer Biol
Department of Molecular Biology, University of Copenhagen, Øster Farimagsgade 2A, 1353 Copenhagen K, Denmark.Seminars in Cancer Biology (Impact Factor: 9.33). 05/2007; 17(2):166-87. DOI: 10.1016/j.semcancer.2006.12.001
Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack, and these inducible PCD forms are intensively studied due their experimental tractability. In general, evidence exists for plant cell death pathways which have similarities to the apoptotic, autophagic and necrotic forms described in yeast and metazoans. Recent research aiming to understand these pathways and their molecular components in plants are reviewed here.
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- "If q P highly declined with increasing EDU concentrations, then PSII excitation pressure (¼1-q P ,Gray et al., 1996) increased (data not shown), suggesting more closed PSII reaction centers. High excitation pressure indicates photon excess and imbalanced energy supply/ demand (Calatayud et al., 2003;Sperdouli and Moustakas, 2014), with following production of ROS (Powles, 1984;Moustaka et al., 2015), increased lipid peroxidation and altered membrane properties (Calatayud et al., 2003) with negative consequences at cell level (Hofius et al., 2007Hofius et al., , 2009). In the present study, EDU mode of action might be related with water and transpiration because there was a positive effect (z11% on average) of 1185, 1778 and 2370 mg L À1 on FSI. "
ABSTRACT: The antiozonant and research tool ethylene diurea (EDU) is widely studied as a phytoprotectant against the widespread pollutant ground-surface ozone. Although it has been extensively used, its potential toxicity in the absence of ozone is unknown and its mode of action is unclear. The purpose of this research was to toxicologically assess EDU and to further investigate its mode of action using Lemna minor L. as a model organism. Application of EDU concentrations greater than 593 mg L−1 (practically 600 mg L−1) resulted in adverse inhibition of colony growth. As no-observed-toxic-effects concentration (NOEL) we recommend a concentration of 296 mg L−1 (practically 300 mg L−1). A hormetic response was detected, i.e. stimulatory effects of low EDU concentrations, which may indicate overcompensation in response to disruption in homeostasis. Growth inhibition and suppressed biomass were associated with impacted chlorophyll a fluorescence (ΦPSII, qP and ETR). Furthermore, EDU increased mesophyll thickness, as indicated by frond succulence index. Applications of concentrations ≥593 mg L−1 to uncontrolled environments should be avoided due to potential toxicity to sensitive organisms and the environment. It can be found at the following link: http://dx.doi.org/10.1016/j.envpol.2015.12.051
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- "Dichos procesos tienen que ver con mecanismos propios de diferentes estados de la planta, como, por ejemplo, la muerte de células aleurónicas durante la germi- Figura 5. a) Micrografía del grano que muestra aleurona de las células del endospermo diferenciadas terminalmente llenas de almidón; b) células de xilema diferenciadas; c) senescencia de la hoja de arce. Fuente:  nación (figura 5a); procesos de diferenciación del xilema (figura 5b); la reproducción y el desarrollo floral; diferenciación sexual de plantas hermafroditas en angiospermas  y durante el desarrollo de procesos de senescencia (figura 5c), la cual comienza con disminución de la rapidez fotosintética, caracterizada por una participación muy activa de las vacuolas y procesos de autofagia  "
ABSTRACT: La comprensión de los mecanismos de defensa de las plantas permite generar conocimiento básico para la conservación y el uso de los recursos filogenéticos, así como para la seguridad alimentaria. Un mecanismo importante en la vida de las plantas es la muerte celular programada, una especie de suicidio celular, reacción hipersensitiva parecida a la apoptosis animal. Este proceso les permite a las plantas el desarrollo de múltiples cambios durante su ciclo biológico, como también la defensa frente al ataque de patógenos y combatir el estrés.
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- "This gene is proposed to be a negative regulator of the defense mechanism and cell death in barley, as a loss-of-function mutation leads to resistance against biotrophic pathogens such as powdery mildews , . Other MLO proteins have been suggested to act as negative regulators of cell-wall apposition formation during non-host resistance , . Furthermore, MLO has been suggested to be a sensor and effector of cellular redox status . "
ABSTRACT: The plant cell cuticle serves as the first barrier protecting plants from mechanical injury and invading pathogens. The cuticle can be breached by cutinase-producing pathogens and the degradation products may activate pathogenesis signals in the invading pathogens. Cuticle degradation products may also trigger the plant's defense responses. Botrytis cinerea is an important plant pathogen, capable of attacking and causing disease in a wide range of plant species. Arabidopsis thaliana shn1-1D is a gain-of-function mutant, which has a modified cuticular lipid composition. We used this mutant to examine the effect of altering the whole-cuticle metabolic pathway on plant responses to B. cinerea attack. Following infection with B. cinerea, the shn1-1D mutant discolored more quickly, accumulated more H2O2, and showed accelerated cell death relative to wild-type (WT) plants. Whole transcriptome analysis of B. cinerea-inoculated shn1-1D vs. WT plants revealed marked upregulation of genes associated with senescence, oxidative stress and defense responses on the one hand, and genes involved in the magnitude of defense-response control on the other. We propose that altered cutin monomer content and composition of shn1-1D plants triggers excessive reactive oxygen species accumulation and release which leads to a strong, unique and uncontrollable defense response, resulting in plant sensitivity and death.
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