scholarly journals Reciprocity between retrograde signal and putative metalloprotease reconfigures plastidial metabolism and structure

2021 ◽  
Author(s):  
Jin-Zheng Wang ◽  
Wilhelmina van de Ven ◽  
Yanmei Xiao ◽  
Xiang He ◽  
Haiyan Ke ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Light Treatment ◽  
High Light ◽  
Retrograde Signaling ◽  
Zinc Binding ◽  
Adaptive Responses ◽  
Wild Type ◽  
Cellular Integrity ◽  
Retrograde Signal

Reconfiguration of the plastidial proteome in response to environmental inputs is central to readjustment of its metabolic and structural states. This is necessary for the functionality of this metabolic hub, and the maintenance of organismal integrity. This report establishes the role of the plastidial retrograde signaling metabolite, MEcPP, in increasing the abundance of the putative plastidial metalloprotease (VIR3), and the ensuing decline of VIR3 target enzymes, ascorbate peroxidase and glyceraldehyde 3-phophate dehydrogenase B. The decreased abundance of these enzymes is linked to increased levels of their substrates: H2O2, an elicitor of salicylic acid production and stromule formation; and G3P the substrate for MEcPP synthesis. High-light treatment of wild type plants recapitulated the VIR3-associated reconfiguration of the plastidial metabolic and structural states. These results identify a previously unrecognized link between the stress-induced plastidial retrograde signaling metabolite and a putative zinc-binding metalloprotease. Moreover, the data reveal that the reciprocity between these two components, results in the reconfiguration of the metabolic and structural states of the plastid, deemed necessary to maintain cellular integrity and to shape adaptive responses.

scholarly journals Chloroplast retrograde signal regulates flowering

2016 ◽  
Vol 113 (38) ◽  
pp. 10708-10713 ◽  
Author(s):  
Peiqiang Feng ◽  
Hailong Guo ◽  
Wei Chi ◽  
Xin Chai ◽  
Xuwu Sun ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Molecular Basis ◽  
Light Quality ◽  
Higher Plants ◽  
High Light ◽  
Retrograde Signaling ◽  
Adaptive Responses ◽  
Detailed Understanding ◽  
Transcriptional Changes ◽  
Retrograde Signal

Light is a major environmental factor regulating flowering time, thus ensuring reproductive success of higher plants. In contrast to our detailed understanding of light quality and photoperiod mechanisms involved, the molecular basis underlying high light-promoted flowering remains elusive. Here we show that, in Arabidopsis, a chloroplast-derived signal is critical for high light-regulated flowering mediated by the FLOWERING LOCUS C (FLC). We also demonstrate that PTM, a PHD transcription factor involved in chloroplast retrograde signaling, perceives such a signal and mediates transcriptional repression of FLC through recruitment of FVE, a component of the histone deacetylase complex. Thus, our data suggest that chloroplasts function as essential sensors of high light to regulate flowering and adaptive responses by triggering nuclear transcriptional changes at the chromatin level.

scholarly journals Salicylic Acid Accumulation Controlled by LSD1 Is Essential in Triggering Cell Death in Response to Abiotic Stress

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 962
Author(s):  
Maciej Jerzy Bernacki ◽  
Anna Rusaczonek ◽  
Weronika Czarnocka ◽  
Stanisław Karpiński
Keyword(s):  
Cell Death ◽  
Salicylic Acid ◽  
Abiotic Stress ◽  
Wild Type ◽  
Pr Genes ◽  
Genes Expression ◽  
Salicylic Acid Accumulation ◽  
Cell Death Phenotype ◽  
Insight Into

Salicylic acid (SA) is well known hormonal molecule involved in cell death regulation. In response to a broad range of environmental factors (e.g., high light, UV, pathogens attack), plants accumulate SA, which participates in cell death induction and spread in some foliar cells. LESION SIMULATING DISEASE 1 (LSD1) is one of the best-known cell death regulators in Arabidopsis thaliana. The lsd1 mutant, lacking functional LSD1 protein, accumulates SA and is conditionally susceptible to many biotic and abiotic stresses. In order to get more insight into the role of LSD1-dependent regulation of SA accumulation during cell death, we crossed the lsd1 with the sid2 mutant, caring mutation in ISOCHORISMATE SYNTHASE 1(ICS1) gene and having deregulated SA synthesis, and with plants expressing the bacterial nahG gene and thus decomposing SA to catechol. In response to UV A+B irradiation, the lsd1 mutant exhibited clear cell death phenotype, which was reversed in lsd1/sid2 and lsd1/NahG plants. The expression of PR-genes and the H2O2 content in UV-treated lsd1 were significantly higher when compared with the wild type. In contrast, lsd1/sid2 and lsd1/NahG plants demonstrated comparability with the wild-type level of PR-genes expression and H2O2. Our results demonstrate that SA accumulation is crucial for triggering cell death in lsd1, while the reduction of excessive SA accumulation may lead to a greater tolerance toward abiotic stress.

Salicylic acid and formation of plant adaptive responses to abiotic stressors: role of signaling network components

2021 ◽  
pp. 135-165
Author(s):  
Yuriy E. Kolupaev ◽  
◽  
Tetiana O. Yastreb ◽  
Aleksey K. Polyakov ◽  
Alexander P. Dmitriev ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Signaling Network ◽  
Adaptive Responses ◽  
Abiotic Stressors

scholarly journals Role of Jasmonic Acid Pathway in Tomato Plant-Pseudomonas syringae Interaction

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 136 ◽  
Author(s):  
Loredana Scalschi ◽  
Eugenio Llorens ◽  
Pilar García-Agustín ◽  
Begonya Vicedo
Keyword(s):  
Gene Expression ◽  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Pseudomonas Syringae ◽  
Tomato Plant ◽  
Wild Type ◽  
Tomato Plants ◽  
Bacterial Pathogenicity ◽  
Acid Pathway

The jasmonic acid pathway has been considered as the backbone of the response against necrotrophic pathogens. However, a hemi-biotrophic pathogen, such as Pseudomonas syringae, has taken advantage of the crosstalk between the different plant hormones in order to manipulate the responses for its own interest. Despite that, the way in which Pseudomonas syringae releases coronatine to activate jasmonic acid-derived responses and block the activation of salicylic acid-mediated responses is widely known. However, the implication of the jasmonic intermediates in the plant-Pseudomonas interaction is not studied yet. In this work, we analyzed the response of both, plant and bacteria using SiOPR3 tomato plants. Interestingly, SiOPR3 plants are more resistant to infection with Pseudomonas. The gene expression of bacteria showed that, in SiOPR3 plants, the activation of pathogenicity is repressed in comparison to wild type plants, suggesting that the jasmonic acid pathway might play a role in the pathogenicity of the bacteria. Moreover, treatments with JA restore the susceptibility as well as activate the expression of bacterial pathogenicity genes. The observed results suggest that a complete jasmonic acid pathway is necessary for the susceptibility of tomato plants to Pseudomonas syringae.

scholarly journals Induction of Systemic Resistance to Botrytis cinerea in Tomato by Pseudomonas aeruginosa 7NSK2: Role of Salicylic Acid, Pyochelin, and Pyocyanin

2002 ◽  
Vol 15 (11) ◽  
pp. 1147-1156 ◽  
Author(s):  
Kris Audenaert ◽  
Theresa Pattery ◽  
Pierre Cornelis ◽  
Monica Höfte
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Salicylic Acid ◽  
Botrytis Cinerea ◽  
Induced Resistance ◽  
Mammalian Cells ◽  
Cell Damage ◽  
Systemic Resistance ◽  
Wild Type ◽  
Induce Resistance

The rhizobacterium Pseudomonas aeruginosa 7NSK2 produces secondary metabolites such as pyochelin (Pch), its precursor salicylic acid (SA), and the phenazine compound pyocyanin. Both 7NSK2 and mutant KMPCH (Pch-negative, SA-positive) induced resistance to Botrytis cinerea in wild-type but not in transgenic NahG tomato. SA-negative mutants of both strains lost the capacity to induce resistance. On tomato roots, KMPCH produced SA and induced phenylalanine ammonia lyase activity, while this was not the case for 7NSK2. In 7NSK2, SA is probably very efficiently converted to Pch. However, Pch alone appeared not to be sufficient to induce resistance. In mammalian cells, Fe-Pch and pyocyanin can act synergistically to generate highly reactive hydroxyl radicals that cause cell damage. Reactive oxygen species are known to play an important role in plant defense. To study the role of pyocyanin in induced resistance, a pyocyanin-negative mutant of 7NSK2, PHZ1, was generated. PHZ1 is mutated in the phzM gene encoding an O-methyltransferase. PHZ1 was unable to induce resistance to B. cinerea, whereas complementation for pyocyanin production or co-inoculation with mutant 7NSK2-562 (Pch-negative, SA-negative, pyocyanin-positive) restored induced resistance. These results suggest that pyocyanin and Pch, rather than SA, are the determinants for induced resistance in wild-type P. aeruginosa 7NSK2.

scholarly journals PAD4-Dependent Antibiosis Contributes to the ssi2-Conferred Hyper-Resistance to the Green Peach Aphid

2010 ◽  
Vol 23 (5) ◽  
pp. 618-627 ◽  
Author(s):  
Joe Louis ◽  
Queena Leung ◽  
Venkatramana Pegadaraju ◽  
John Reese ◽  
Jyoti Shah
Keyword(s):  
Arabidopsis Thaliana ◽  
Salicylic Acid ◽  
Green Peach Aphid ◽  
Insect Behavior ◽  
Antibiotic Activity ◽  
Broad Host Range ◽  
Wild Type ◽  
Elevated Expression ◽  
Insect Reproduction

Myzus persicae, commonly known as green peach aphid (GPA), is a sap-sucking insect with a broad host range. Arabidopsis thaliana responds to GPA infestation with elevated expression of the PHYTOALEXIN DEFICIENT4 (PAD4) gene. Previously, we had demonstrated that the loss of PAD4 gene function compromises Arabidopsis resistance to GPA. In contrast, a mutation in the Arabidopsis SUPPRESSOR OF SALICYLIC ACID INSENSITIVITY2 (SSI2) gene, which encodes a desaturase involved in lipid metabolism, resulted in hyper-resistance to GPA. We demonstrate here that PAD4 is required for the ssi2-dependent heightened resistance to GPA. Based on electrical monitoring of insect behavior and bioassays in which the insect was given a choice between the wild type and the ssi2 mutant, it is concluded that the ssi2-conferred resistance is not due to deterrence of insect settling or feeding from the phloem of the mutant. Instead, hyper-resistance in the ssi2 mutant results from heightened antibiosis that curtails insect reproduction. Petiole exudates collected from uninfested ssi2 plants contain elevated levels of an activity that interferes with aphid reproduction in synthetic diets. PAD4 was required for the accumulation of this antibiotic activity in petiole exudates, supporting the role of PAD4 in phloem-based resistance. Because PAD4 expression is not elevated in the ssi2 mutant, we suggest that basal PAD4 expression contributes to this antibiosis.

scholarly journals Identification of salicylic acid-independent responses in an Arabidopsis phosphatidylinositol 4-kinase beta double mutant

2019 ◽  
Vol 125 (5) ◽  
pp. 775-784 ◽  
Author(s):  
Tetiana Kalachova ◽  
Martin Janda ◽  
Vladimír Šašek ◽  
Jitka Ortmannová ◽  
Pavla Nováková ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Pseudomonas Syringae ◽  
Double Mutant ◽  
Plant Defence ◽  
Blumeria Graminis ◽  
Wild Type ◽  
Triple Mutant ◽  
Independent Manner ◽  
Phosphatidylinositol 4

Abstract Background and Aims We have recently shown that an Arabidopsis thaliana double mutant of type III phosphatidylinositol-4-kinases (PI4Ks), pi4kβ1β2, constitutively accumulated a high level of salicylic acid (SA). By crossing this pi4kβ1β2 double mutant with mutants impaired in SA synthesis (such as sid2 impaired in isochorismate synthase) or transduction, we demonstrated that the high SA level was responsible for the dwarfism phenotype of the double mutant. Here we aimed to distinguish between the SA-dependent and SA-independent effects triggered by the deficiency in PI4Kβ1 and PI4Kβ2. Methods To achieve this we used the sid2pi4kβ1β2 triple mutant. High-throughput analyses of phytohormones were performed on this mutant together with pi4kβ1β2 and sid2 mutants and wild-type plants. Responses to pathogens, namely Hyaloperonospora arabidopsidis, Pseudomonas syringae and Botrytis cinerea, and also to the non-host fungus Blumeria graminis, were also determined. Callose accumulation was monitored in response to flagellin. Key Results We show here the prominent role of high SA levels in influencing the concentration of many other tested phytohormones, including abscisic acid and its derivatives, the aspartate-conjugated form of indole-3-acetic acid and some cytokinins such as cis-zeatin. We show that the increased resistance of pi4kβ1β2 plants to the host pathogens H. arabidopsidis, P. syringae pv. tomato DC3000 and Bothrytis cinerea is dependent on accumulation of high SA levels. In contrast, accumulation of callose in pi4kβ1β2 after flagellin treatment was independent of SA. Concerning the response to Blumeria graminis, both callose accumulation and fungal penetration were enhanced in the pi4kβ1β2 double mutant compared to wild-type plants. Both of these processes occurred in an SA-independent manner. Conclusions Our data extensively illustrate the influence of SA on other phytohormone levels. The sid2pi4kβ1β2 triple mutant revealed the role of PI4Kβ1/β2 per se, thus showing the importance of these enzymes in plant defence responses.

scholarly journals Role of an ancient light-harvesting protein of PSI in light absorption and photoprotection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yandu Lu ◽  
Qinhua Gan ◽  
Masakazu Iwai ◽  
Alessandro Alboresi ◽  
Adrien Burlacot ◽  
...  
Keyword(s):  
Light Absorption ◽  
Red Algae ◽  
Light Harvesting ◽  
High Light ◽  
Secondary Endosymbiosis ◽  
Ros Production ◽  
Nannochloropsis Oceanica ◽  
Wild Type ◽  
Dynamic Balancing

AbstractDiverse algae of the red lineage possess chlorophyll a-binding proteins termed LHCR, comprising the PSI light-harvesting system, which represent an ancient antenna form that evolved in red algae and was acquired through secondary endosymbiosis. However, the function and regulation of LHCR complexes remain obscure. Here we describe isolation of a Nannochloropsis oceanica LHCR mutant, named hlr1, which exhibits a greater tolerance to high-light (HL) stress compared to the wild type. We show that increased tolerance to HL of the mutant can be attributed to alterations in PSI, making it less prone to ROS production, thereby limiting oxidative damage and favoring growth in HL. HLR1 deficiency attenuates PSI light-harvesting capacity and growth of the mutant under light-limiting conditions. We conclude that HLR1, a member of a conserved and broadly distributed clade of LHCR proteins, plays a pivotal role in a dynamic balancing act between photoprotection and efficient light harvesting for photosynthesis.

scholarly journals The plastid-nucleus located DNA/RNA binding protein WHIRLY1 regulates microRNA-levels during stress

2017 ◽  
Author(s):  
Aleksandra Swida-Barteczka ◽  
Anja Krieger-Liszkay ◽  
Wolfgang Bilger ◽  
Ulrike Voigt ◽  
Götz Hensel ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Nuclear Gene ◽  
Retrograde Signaling ◽  
Wild Type ◽  
Transcriptional Responses ◽  
Stress Dependent

In this article a novel mechanism of retrograde signaling by chloroplasts during stress is described. This mechanism involves the DNA/RNA binding protein WHIRLY1 as a regulator of microRNA levels. By virtue of its dual localization in chloroplasts and the nucleus of the same cell, WHIRLY1 was proposed as an excellent candidate coordinator of chloroplast function and nuclear gene expression (Grabowski et al., 2008; Foyer et al., 2014). In this study the putative involvement of WHIRLY1 in stress dependent retrograde signaling was investigated by comparison of barley (Hordeum vulgare L., cv. Golden Promise) wild-type and transgenic plants with an RNAi-mediated knockdown of WHIRLY1. In contrast to the wild type, the transgenic plants were unable to cope with continuous high light conditions. They were impaired in production of several microRNAs mediating post-transcriptional responses during stress (Kruszka et al., 2012, Sunkar et al., 2012). The results support a central role of WHIRLY1 in retrograde signaling and underpin a so far underestimated role of microRNAs in this process.

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