Construction of gene expression profiles for anoxia-reoxygenation in Arabidopsis
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ABSTRACT: To understand how plants respond to anoxia-reoxygenation, we have employed a global microarray expression profiling as a basic platform to characterize genes with the potential to mediate the recovery responses in Arabidopsis. 7-day-old seedlings were trated with 4hr and 8hr anoxia, and then reoxygenated in air for 0, 0.5, 1, 3, 6 hrs. Genes changed in both condition were designated as reoxygenation-regulated genes. They included the genes in ROS detoxification, dehydration, metabolic process, and many other responses. Interestingly, ethylene was also involved in this recovery process. We further adopted ein2-5 and ein3eil1 microarray to investigate ethylene signaling. Our results showed ethylene partially regulate reoxygenation regulated genes and is reruired for plant survival in reoxygenation.
Project description:To understand how plants respond to anoxia-reoxygenation, we have employed a global microarray expression profiling as a basic platform to characterize genes with the potential to mediate the recovery responses in Arabidopsis. 7-day-old seedlings were trated with 4hr and 8hr anoxia, and then reoxygenated in air for 0, 0.5, 1, 3, 6 hrs. Genes changed in both condition were designated as reoxygenation-regulated genes. They included the genes in ROS detoxification, dehydration, metabolic process, and many other responses. Interestingly, ethylene was also involved in this recovery process. We further adopted ein2-5 and ein3eil1 microarray to investigate ethylene signaling. Our results showed ethylene partially regulate reoxygenation regulated genes and is reruired for plant survival in reoxygenation. Genes expression during anoxia-reoxygenation in Arabidopsis seedlings was measured at 0, 0.5, 1, 3, 6 hours after anoxia treatment, and normal condition before anoxia. Three independent experiments were performed at each time (Nor, 0, 0.5, 1, 3, 6) under 4hr anoxia-reoxygenation condition by using Col-0, ein2-5, and ein3eil1. Four independent experiments were performed at each time (Nor, 0, 0.5, 1, 3, 6) under 8hr anoxia-reoxygenation condition by using Col-0.
Project description:The freshwater fish crucian carp (Carassius carassius) can survive complete oxygen depletion (anoxia) for several months at low temperatures, achieved by a combination of reduced energy demand and increased glycolysis fueled by large hepatic glycogen stores. In crucian carp, the energy-requiring protein synthesis is controlled in a tissue-specific manner when oxygen levels decrease. During anoxia, translational rates are maintained at almost normoxic levels in brain, while heart and liver translation rates are strongly reduced. However, little is known about how the global proteome of these tissues are affected by oxygen variations. By applying mass spectrometry-based proteomics, 3304 proteins in brain, 3004 proteins in heart and 2516 proteins in liver were detected, of which 66 brain proteins, 243 cardiac proteins and 162 hepatic proteins were differentially expressed during the course of anoxia-reoxygenation compared to normoxic control. The brain proteome showed few differences in response to oxygen variations, indicating that anoxic survival is not regulated through protein expression in this tissue. Cardiac and hepatic adaptions to anoxia included enrichment of mitochondrial proteins involved in aerobic respiration and mitochondrial membrane integrity. We show that enzymes in the electron transport system (ETS) are regulated in a tissue-specific manner since no ETS components were regulated in brain, but were downregulated in heart and upregulated in liver during anoxia and reoxygenation. Furthermore, complement system activation was enriched in heart during anoxia. During reoxygenation, proteins involved in the cristae junction organization were regulated in the heart, possibly explaining how reactive oxygen species can be avoided when oxygen returns in this master of anoxic survival.
Project description:The freshwater fish crucian carp (Carassius carassius) are able to survive chronic anoxia for several months at low temperatures. Consequently, anoxia-related physiological and biochemical adaptations in this species have been studied for more than half a century. Still, despite for the well-known role of protein phosphorylation in regulating cellular processes, no studies have comprehensively characterized the phosphoproteome in crucian carp. In this study, we report the global phosphoproteome in crucian carp brain and liver during anoxia and reoxygenation. By applying a bottom-up proteomic approach on enriched phosphopeptides we found that the brain phosphoproteome show surprisingly few changes during anoxia-reoxygenation exposure with 110 out of 4316 phosphopeptides being differentially regulated. By contrast, in the liver 395 out of 1293 phosphopeptides were regulated. Although most changes occurred in the liver phosphoproteome, we found evidence for metabolic depression and decreased translation in both brain and liver. We also found regulated phosphoproteins involved in apoptotic regulation and reactive oxygen species handling in both tissues. In the brain, some of the most regulated phosphopeptides belonged to proteins involved in central nervous system development and neuronal activity at the synaptic cleft. Regulated phosphoproteins specific for liver tissue were related to glucose metabolism, including glycolytic flux and glycogenolysis, and the ubiquitin-proteasome system.
Project description:Anoxia induces several heat shock proteins and a heat pre-treatment can acclimatize Arabidopsis seedlings to a subsequent anoxic treatment. In this work we analyzed the response of Arabidopsis seedlings to anoxia, heat and a combined heat+anoxia stress. A significant overlapping between the anoxic and heat shock responses has been observed by whole-genome microarray analysis.
Project description:to investigated the effect of two reoxygenation treatments on T. blochii after 12 h of hypoxic stress (1.9 ± 0.2 mg/L): gradual reoxygenation (GRG: DO recovery within 3 h) and rapid reoxygenation (RRG: DO recovery within 10 mins).
Project description:A complex interplay between ethylene, ETP1/ETP2 F-box proteins, and degradation of EIN2 is essential for triggering ethylene responses in plants. The gaseous plant hormone ethylene can trigger myriad physiological and morphological responses in plants. While many ethylene signaling pathway components have been identified and characterized, little is known about the function of the integral membrane protein EIN2, a central regulator of all ethylene responses. Here, we demonstrate that Arabidopsis thaliana EIN2 is a protein with a short half-life that undergoes rapid proteasome-mediated protein turnover. Moreover, EIN2 protein accumulation is positively regulated by ethylene. We identified two F-box proteins, EIN2 TARGETING PROTEIN and 2 (ETP1 and ETP2), that interact with the EIN2 carboxyl-terminal domain (CEND), which is highly conserved and sufficient to activate most ethylene responses. Overexpression of ETP1 or ETP2 disrupts EIN2 protein accumulation, and these plants manifest a strong ethylene insensitive phenotype. Furthermore, knocking down the levels of both ETP1 and ETP2 mRNAs using an artificial microRNA (amiRNA) leads to accumulation of EIN2 protein, resulting in plants that display constitutive ethylene response phenotypes. Finally, ethylene down-regulates ETP1 and ETP2 proteins, impairing their ability to interact with EIN2. Thus, these studies reveal that a complex interplay between ethylene, the regulation of ETP1/ETP2 F-box proteins, and subsequent targeting and degradation of EIN2 is essential for triggering ethylene responses in plants. Keywords: ethylene treatment, genetic modification
Project description:Seed size is related to plant evolution and crop yield and is affected by genetic mutations, imprinting, and genome dosage. Imprinting is a widespread epigenetic phenomenon in mammals and flowering plants. ETHYLENE INSENSITIVE2 (EIN2) encodes a membrane protein that links the ethylene perception to transcriptional regulation. Interestingly, during seed development EIN2 is maternally-expressed in Arabidopsis and maize, but the role of EIN2 in seed development is unknown. Here we show that EIN2 is expressed specifically in the endosperm, and the maternal-specific EIN2 expression affects temporal regulation of endosperm cellularization. As a result, seed size increases in the genetic cross using the ein2 mutant as the maternal parent or in the ein2 mutant. The maternal-specific expression of EIN2 in the endosperm is controlled by DNA methylation but not by H3K27me3 or by ethylene and several ethylene pathway genes tested. RNA-seq analysis in the endosperm isolated by laser-capture microdissection show upregulation of many endosperm-expressed genes such as AGAMOUS-LIKEs (AGLs) in the ein2 mutant or when the maternal EIN2 allele is not expressed. EIN2 does not interact with DNA and may act through ETHYLENE INSENSITIVE3 (EIN3), a DNA binding protein present in sporophytic tissues, to activate target genes like AGLs, which in turn mediate temporal regulation of endosperm cellularization and seed size. These results provide mechanistic insights into endosperm and maternal-specific expression of EIN2 on endosperm cellularization and seed development, which could help improve seed production in plants and crops.
Project description:Anoxia induces several heat shock proteins and a heat pre-treatment can acclimatize Arabidopsis seedlings to a subsequent anoxic treatment. In this work we analyzed the response of Arabidopsis seedlings to anoxia, heat and a combined heat+anoxia stress. A significant overlapping between the anoxic and heat shock responses has been observed by whole-genome microarray analysis. Experiment Overall Design: We treated Arabidopsis seedling, 4-days old, dark germinated with: Experiment Overall Design: -Control (23°C, dark, liquid Murashige-Skoog medium containing 30mM sucrose). Experiment Overall Design: -Heat-treated (38°C for 90 minutes, dark, liquid Murashige-Skoog medium containing 30mM sucrose). Experiment Overall Design: -Anoxia-treated (23°C, under anoxia for 6h, dark, liquid Murashige-Skoog medium containing 30mM sucrose). Experiment Overall Design: -combined heat+Anoxia-treatment (23°C, treated at 38°C for 90 min and thereafter under anoxia for 6h, dark, liquid Murashige-Skoog medium containing 30mM sucrose). Experiment Overall Design: Two biological replicates for each condition.
Project description:Arabidopsis thaliana ecotype Columbia glabra were grown for 4 days in the dark without added sucrose. Samples were subsequently kept for 6h either [1] under aerobic conditions, [2] under anoxia in absence of sucrose or [3] under anoxia in presence of sucrose. Keywords: other
Project description:Gene expression analysis of 7d-old Arabidopsis seedlings exposed to short term (2 h) hypoxia, long term (9 h) hypoxia, and 1 h reoxygenation after long term (9 h) hypoxia to evaluate the regulation of gene expression at the level of translation. Keywords: Time Course, hypoxia recovery, polysomal mRNA, IP RNA, polysomes, hypoxia stress, reoxygenation, translational control.