scholarly journals Transcription Factor NAC075 Delays Leaf Senescence by Deterring Reactive Oxygen Species Accumulation in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Chengcheng Kan ◽  
Yi Zhang ◽  
Hou-Ling Wang ◽  
Yingbai Shen ◽  
Xinli Xia ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Transcription Factor ◽  
Leaf Senescence ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Mobility Shift

Leaf senescence is a highly complex genetic process that is finely tuned by multiple layers of regulation. Among them, transcriptional regulation plays a critical role in controlling the initiation and progression of leaf senescence. Here, we found that the NAC transcription factor NAC075 functions as a novel negative regulator of leaf senescence. Loss of function of NAC075 promotes leaf senescence in an age-dependent manner, whereas constitutive overexpression of NAC075 delays senescence in Arabidopsis. Transcriptome analysis revealed that transcript levels of antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) are significantly suppressed in nac075 mutants compared with wild-type plants. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) analyses revealed that NAC075 directly binds the promoter of catalase 2 (CAT2). Moreover, genetic analysis showed that overexpression of CAT2 suppresses the overproduction of reactive oxygen species (ROS) and the early senescence phenotypes of nac075 mutants, suggesting that CAT2 acts downstream of NAC075 to delay leaf senescence by repressing ROS accumulation. Collectively, our findings provide a new regulatory module involving NAC075-CAT2-ROS in controlling leaf senescence in Arabidopsis.

scholarly journals Crosstalk between Brassinosteroid and Redox Signaling Contributes to the Activation of CBF Expression during Cold Responses in Tomato

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 509
Author(s):  
Pingping Fang ◽  
Yu Wang ◽  
Mengqi Wang ◽  
Feng Wang ◽  
Cheng Chi ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cold Stress ◽  
Stress Responses ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Central Component ◽  
H2o2 Production ◽  
Plant Responses ◽  
Oxygen Species ◽  
Loss Of Function

Brassinosteroids (BRs) play a critical role in plant responses to stress. However, the interplay of BRs and reactive oxygen species signaling in cold stress responses remains unclear. Here, we demonstrate that a partial loss of function in the BR biosynthesis gene DWARF resulted in lower whilst overexpression of DWARF led to increased levels of C-REPEAT BINDING FACTOR (CBF) transcripts. Exposure to cold stress increased BR synthesis and led to an accumulation of brassinazole-resistant 1 (BZR1), a central component of BR signaling. Mutation of BZR1 compromised the cold- and BR-dependent increases in CBFs and RESPIRATORY BURST OXIDASE HOMOLOG 1(RBOH1) transcripts, as well as preventing hydrogen peroxide (H2O2) accumulation in the apoplast. Cold- and BR-induced BZR1 bound to the promoters of CBF1, CBF3 and RBOH1 and promoted their expression. Significantly, suppression of RBOH1 expression compromised cold- and BR-induced accumulation of BZR1 and related increases in CBF transcripts. Moreover, RBOH1-dependent H2O2 production regulated BZR1 accumulation and the levels of CBF transcripts by influencing glutathione homeostasis. Taken together, these results demonstrate that crosstalk between BZR1 and reactive oxygen species mediates cold- and BR-activated CBF expression, leading to cold tolerance in tomato (Solanum lycopersicum).

scholarly journals Heat stress transcription factor OsSPL7 plays a critical role in reactive oxygen species balance and stress responses in rice

Plant Science ◽  
2019 ◽  
Vol 289 ◽  
pp. 110273 ◽  
Author(s):  
Trung Viet Hoang ◽  
Kieu Thi Xuan Vo ◽  
Md Mizanor Rahman ◽  
Seok-Hyun Choi ◽  
Jong-Seong Jeon
Keyword(s):  
Reactive Oxygen Species ◽  
Transcription Factor ◽  
Heat Stress ◽  
Stress Responses ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Oxygen Species

scholarly journals NTRC and Chloroplast-Generated Reactive Oxygen Species Regulate Pseudomonas syringae pv. tomato Disease Development in Tomato and Arabidopsis

2012 ◽  
Vol 25 (3) ◽  
pp. 294-306 ◽  
Author(s):  
Yasuhiro Ishiga ◽  
Takako Ishiga ◽  
Tamding Wangdi ◽  
Kirankumar S. Mysore ◽  
Srinivasa Rao Uppalapati
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Pseudomonas Syringae ◽  
Function Analysis ◽  
Virulent Strain ◽  
Reactive Oxygen ◽  
Forward Genetics ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Oxygen Species

Coronatine (COR)-producing pathovars of Pseudomonas syringae, including pvs. tomato, maculicola, and glycinea, cause important diseases on tomato, crucifers, and soybean, respectively, and produce symptoms with necrotic lesions surrounded by chlorosis. The chlorosis is mainly attributed to COR. However, the significance of COR-induced chlorosis in localized lesion development and the molecular basis of disease-associated cell death is largely unknown. To identify host (chloroplast) genes that play a role in COR-mediated chlorosis, we used a forward genetics approach using Nicotiana benthamiana and virus-induced gene silencing and identified a gene which encodes 2-Cys peroxiredoxin (Prxs) that, when silenced, produced a spreading hypersensitive or necrosis-like phenotype instead of chlorosis after COR application in a COI1-dependent manner. Loss-of-function analysis of Prx and NADPH-dependent thioredoxin reductase C (NTRC), the central players of a chloroplast redox detoxification system, resulted in spreading accelerated P. syringae pv. tomato DC3000 disease-associated cell death with enhanced reactive oxygen species (ROS) accumulation in a COR-dependent manner in tomato and Arabidopsis. Consistent with these results, virulent strain DC3000 suppressed the expression of Prx and NTRC in Arabidopsis and tomato during pathogenesis. However, interestingly, authentic COR suppressed the expression of Prx and NTRC in tomato but not in Arabidopsis, suggesting that COR in conjunction with other effectors may modulate ROS and cell death in different host species. Taken together, these results indicated that NTRC or Prx function as a negative regulator of pathogen-induced cell death in the healthy tissues that surround the lesions, and COR-induced chloroplast-localized ROS play a role in enhancing the disease-associated cell death.

scholarly journals Reactive Oxygen Species coordinate the transcriptional responses to iron availability in Arabidopsis

2020 ◽  
Author(s):  
Claudia von der Mark ◽  
Rumen Ivanov ◽  
Monique Eutebach ◽  
Veronica G Maurino ◽  
Petra Bauer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Fe Deficiency ◽  
Plant Responses ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Transcriptional Responses ◽  
Fe Homeostasis ◽  
Regulatory Loop

Abstract Reactive oxygen species play a central role in the regulation of plant responses to environmental stress. Under prolonged iron (Fe) deficiency, increased levels of hydrogen peroxide (H2O2) initiate signaling events, resulting in the attenuation of Fe acquisition through the inhibition of FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT). As this H2O2 increase occurs in a FIT-dependent manner, our aim was to understand the processes involved in maintaining H2O2 levels under prolonged Fe deficiency and the role of FIT in this process. We identified CAT2 gene, encoding one of the three Arabidopsis catalase isoforms, as regulated by FIT. CAT2 loss-of-function plants displayed severe susceptibility to Fe deficiency and greatly increased H2O2 levels in roots. Analysis of the Fe homeostasis transcriptional cascade revealed that H2O2 influences the gene expression of downstream regulators FIT, BHLHs of group Ib and POPEYE (PYE), however H2O2 did not affect their upstream regulators, such as BHLH104 and ILR3. Our data shows that FIT and CAT2 participate in a regulatory loop between H2O2 and prolonged Fe deficiency.

scholarly journals WRKY55 transcription factor positively regulates leaf senescence and the defense response by modulating the transcription of genes implicated in the biosynthesis of reactive oxygen species and salicylic acid in Arabidopsis

Development ◽  
2020 ◽  
Vol 147 (16) ◽  
pp. dev189647
Author(s):  
Yiqiao Wang ◽  
Xing Cui ◽  
Bo Yang ◽  
Shutao Xu ◽  
Xiangyan Wei ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Transcription Factor ◽  
Salicylic Acid ◽  
Pseudomonas Syringae ◽  
Leaf Senescence ◽  
Single Gene ◽  
Bacterial Pathogen ◽  
Reactive Oxygen ◽  
Pathogen Resistance ◽  
Oxygen Species

ABSTRACTReactive oxygen species (ROS) and salicylic acid (SA) are two factors regulating leaf senescence and defense against pathogens. However, how a single gene integrates both ROS and SA pathways remains poorly understood. Here, we show that Arabidopsis WRKY55 transcription factor positively regulates ROS and SA accumulation, and thus leaf senescence and resistance against the bacterial pathogen Pseudomonas syringae. WRKY55 is predominantly expressed in senescent leaves and encodes a transcriptional activator localized to nuclei. Both inducible and constitutive overexpression of WRKY55 accelerates leaf senescence, whereas mutants delay it. Transcriptomic sequencing identified 1448 differentially expressed genes, of which 1157 genes are upregulated by WRKY55 expression. Accordingly, the ROS and SA contents in WRKY55-overexpressing plants are higher than those in control plants, whereas the opposite occurs in mutants. Moreover, WRKY55 positively regulates defense against P. syringae. Finally, we show that WRKY55 activates the expression of RbohD, ICS1, PBS3 and SAG13 by binding directly to the W-box-containing fragments. Taken together, our work has identified a new WRKY transcription factor that integrates both ROS and SA pathways to regulate leaf senescence and pathogen resistance.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

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