Arabidopsis thaliana
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA397381 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Leaf senescence is a highly coordinated and complicated process with the integration of numerous internal and environmental signals. Salicylic acid (SA) and reactive oxygen species (ROS) are two well-defined inducers of leaf senescence, whose contents progressively and inter-dependently increase during leaf senescence via a yet unknown mechanism. Here, we have characterized a newly identified positive regulator of leaf senescence, WRKY75, and demonstrated that knock-down or knock-out of WRKY75 delays, while over-expression of WRKY75 accelerates age-dependent leaf senescence. The WRKY75 transcription is induced by age, SA, H2O2, as well as multiple plant hormones. Meanwhile, WRKY75 is able to promote SA production by inducing the transcription of SA INDUCTION-DEFICIENT 2 (SID2), and suppress H2O2 scavenging partly by repressing the transcription of CATALASE 2 (CAT2). Genetic analysis reveals that the SID2 mutation or an increase of catalase activity rescues the precocious leaf senescence phenotype evoked by WRKY75 over-expression. Based on these results, we propose a “tripartite amplification loop” model in which WRKY75, SA and ROS undergo a gradual but self-sustained rise driven by three interlinked positive feedback regulations. This tripartite amplification loop provides a molecular framework connecting the upstream signals, such as age, ethylene, JA and ABA, to the downstream regulatory network executed by those SA-responsive and H2O2-responsive transcription factors during leaf senescence.
2017-11-07 | GSE102302 | GEO
Project description:Leaf senescence is a developmental process designed for nutrient recycling and relocation to maximize growth competence and reproductive capacity of plants. Thus, plants integrate developmental and environmental signals to precisely control senescence. However, it remains largely elusive as to how plants coordinate genetic, epigenetic, and metabolic pathways for the regulation of senescence. To genetically dissect the complex regulatory mechanism underlying leaf senescence, we identified an early leaf senescence mutant, rse1. RSE1 encodes a putative glycosyltranferase. Loss-of-function mutations in RSE1 resulted in precocious leaf yellowing and up-regulation of senescence maker genes, indicating enhanced leaf senescence. Transcriptome analysis revealed that salicylic acid (SA) and defense signaling cascades were activated in rse1 prior to the onset of leaf senescence. In agreement with the phenotypes, we found that SA accumulation was significantly increased in rse1. We also discovered that the rse1 phenotypes are dependent on SA-INDUCTION DEFICIENT 2 (SID2), indicating a role of SA in accelerated leaf senescence in rse1. Furthermore, RSE1 protein was localized to the cell walls, and rse1 displayed increased glucose contents in the cell walls, implying a possible link between the cell walls and RSE1 function. Together, we show that RSE1 negatively modulate leaf senescence through an SID2-dependent SA signaling pathway.
2019-10-18 | GSE132740 | GEO
Project description:Analysis of leaves from 3-week old transgenic plants overexpressing AAF, which is a senescence-associated gene. Overexpression of AAF promoted leaf senescence and accumulation of reactive oxygen species (ROS) in transgenic plants. Results provide insight in the role of AAF in ROS homeostasis and the function in leaf senescence.
2010-09-30 | GSE18336 | GEO
Project description:The downstream events and target genes of p53 in senescence responses are not fully understood. Here, we report a novel function of the forkhead transcription factor Foxp3, a key player in mediating T cell inhibitory function, in p53-mediated cellular senescence. Overexpression of Foxp3 in mouse embryonic fibroblasts (MEFs) accelerates senescence, whereas Foxp3 knockdown leads to escape from p53-mediated senescence in p53-expressing MEFs. Consistently, Foxp3 expression resulted in the induction of senescence in epithelial cancer cells, including MCF7 and HCT116. Foxp3 overexpression also increased the intracellular levels of reactive oxygen species (ROS). The ROS inhibitor N-acetyl-L-cysteine rescued Foxp3 expression-induced senescence. Furthermore, the elevated ROS levels that accompanied Foxp3 overexpression were paralleled by an increase in p21 expression. Knockdown of p21 in Foxp3-expressing MEFs abrogated the Foxp3-dependent increase in ROS levels, indicating that Foxp3 acts through p21 induction and subsequent ROS elevation to trigger senescence. Collectively, these results suggest that Foxp3 is a downstream target of p53 that is sufficient to induce p21 expression and ROS production and is necessary for p53-mediated senescence. control and treated samples (human), young passage (p3) or old passage (p7) samples (mouse)
2015-08-13 | E-GEOD-71980 | biostudies-arrayexpress
Project description:Heterosis, or hybrid vigor, has been exploited in agriculture to deliver increases in crop yields for over a century, yet the molecular basis is not well understood We have studied the transcriptomes of 15 day old seedlings from intraspecific Arabidopsis hybrids with varying levels of heterosis and their parental lines in order to identify drivers of heterosis. The patterns of altered gene expression in the hybrids point to a reduction in basal defense levels that could reflect the antagonism between plant immunity and plant growth. Associated with this theme are changes to the salicylic acid and auxin regulated networks which are known to control abiotic and biotic defense responses as well as being important regulators of plant growth. Increased auxin response correlates with the heterotic phenotype of greater leaf cell numbers, whereas reduced salicylic acid levels and response promotes increased leaf cell size in hybrids involving C24. By manipulating salicylic acid levels in each of our hybrid systems, we can alter levels of heterosis, promote additional growth in the hybrids, and generate increased growth in the parents, especially C24.
2015-10-01 | GSE64475 | GEO
Project description:Leaf senescence, the last step of leaf development, is a highly regulated process, modulated by a number of internal and external factors. During the senescence process resources like nitrogen (N) are remobilized from senescent tissues to sink tissues. This intrinsically depends on the accurate dispersion of resources according to sink strength of various organs competing with each other. Consequently, N deficiency accelerates barley leaf senescence and its resupply can delay the senescence progression. In order to identify genetic and metabolic factors that regulate leaf senescence in response to N supply, transcriptomic and global metabolic rearrangements were analyzed in barley primary at early and later stages of N deprivation, and after N resupply to N-deficient plants.
2018-04-09 | E-MTAB-6710 | biostudies-arrayexpress
Project description:Analysis of leaves from 3-week old transgenic plants overexpressing AAF, which is a senescence-associated gene. Overexpression of AAF promoted leaf senescence and accumulation of reactive oxygen species (ROS) in transgenic plants. Results provide insight in the role of AAF in ROS homeostasis and the function in leaf senescence. 3-week-old plants of Col-0 (wild type, as control) and AAF-OX (overexpression line) were grown in long day condition (16hr light/8hr dark). Rosette leaves of Col-0 and AAF-OX were used for total RNA extraction and cDNA synthesis. cDNA labeling, array hybridization, and scanning followed standard Affymetrix expression array protocol. Two independent sets of microarray analyses were performed in this study.
2010-09-30 | E-GEOD-18336 | biostudies-arrayexpress
Project description:As sessile organism, plants evolved a highly complicated signaling system to cope with unfavorable and fluctuating environmental conditions. Rapid and transient Reactive Oxygen Species (ROS) burst is a common response to both biotic and abiotic stresses. Plants exposed with O3 could trigger extracellular similar ROS production through cell wall peroxidases and NPADPH oxidases, resulting in changes in the gene expression and cell death. Whereas ROS induced cell death is not simply due to its toxicity, rather due to interplay with several other signaling pathways, such as salicylic acid (SA), jasmonic acid (JA) and ethylene signaling pathways. Furthermore, the three hormones have both synergistic and antagonistic interactions, where the suppression of JA signaling by SA is the mostly studied. In addition, ethylene promotes cell death while JA has a protective role upon O3 exposure. The role of SA is more complicated; depending on the genetic background it can have either cell death promoting or protecting roles. Hence, a clean system to deliver apoplastic ROS is required to study the role of ROS apart from con-current activation of other signaling pathways. Arabidopsis thaliana offer a convenient system to study apoplastic ROS signaling due to the availability of hormone signaling or biosynthesis mutants including the JA receptor mutant coi1-16 (CORONATINE INSENSITIVE1), the essential ethylene signaling mutant ein2 (ETHYLENE INSENSITIVE2), the SA biosynthesis mutant sid2 (SALICYLIC ACID INDUCTION DEFICIENT2 also known as ISOCHORISMATE SYNTHASE1), and essential regulators in SA/JA/ethylene-induced defense response triple mutant tga2 tga5 tga6 (Clade II TGA transcription factors). Here we used a combination of transcriptome analysis, cell death assays and mutant analysis to systematically quantified the contribution of hormone signaling in relation to apoplastic ROS signaling, identified transcription factors (TFs) involved in ROS regulation and dissected the components involved in defense hormones associated cell death. Transcriptome profiling of ozone response using two arabidopsis triple mutants coi1-16 ein2 sid2 and tga2 tga5 tga6 related to Jasmonic acid, salicylic acid and ethylene signaling to identify hormone-independant apoplastic ROS signaling
2015-02-10 | E-GEOD-65740 | biostudies-arrayexpress
Project description:The downstream events and target genes of p53 in the process of senescence are not fully understood. Here, we report a novel function of the forkhead transcription factor Foxp3, which is a key player in mediating T cell inhibitory functions, in p53-mediated cellular senescence. The overexpression of Foxp3 in mouse embryonic fibroblasts (MEFs) accelerates senescence, whereas Foxp3 knockdown leads to escape from p53-mediated senescence in p53-expressing MEFs. Consistent with these results, Foxp3 expression resulted in the induction of senescence in epithelial cancer cells, including MCF7 and HCT116 cells. Foxp3 overexpression also increased the intracellular levels of reactive oxygen species (ROS). The ROS inhibitor N-acetyl-L-cysteine rescued cells from Foxp3-expression-induced senescence. Furthermore, the elevated ROS levels that accompanied Foxp3 overexpression were paralleled by an increase in p21 expression. Knockdown of p21 in Foxp3-expressing MEFs abrogated the Foxp3-dependent increase in ROS levels, indicating that Foxp3 acts through the induction of p21 and the subsequent ROS elevation to trigger senescence. Collectively, these results suggest that Foxp3 is a downstream target of p53 that is sufficient to induce p21 expression and ROS production and is necessary for p53-mediated senescence.
2015-08-13 | GSE71980 | GEO