scholarly journals Translocation of chloroplast NPR1 to the nucleus in retrograde signaling for adaptive response to salt stress in tobacco

2021 ◽  
Author(s):  
Ky Young Park ◽  
So Yeon Seo
Keyword(s):  
Salt Stress ◽  
Stress Responses ◽  
Environmental Changes ◽  
Protein A ◽  
Transit Peptide ◽  
Retrograde Signaling ◽  
Wild Type Plant ◽  
Dependent Manner ◽  
Biotic And Abiotic Stress ◽  
Chloroplast Transit Peptide

Chloroplasts play a pivotal role in biotic and abiotic stress responses, accompanying changes in the cell reduction/oxidation (redox) state. Chloroplasts are an endosymbiotic organelle that sends retrograde signals to the nucleus to integrate with environmental changes. This study showed that salt stress causes the rapid accumulation of the nonexpressor of pathogenesis-related genes 1 (NPR1) protein, a redox-sensitive transcription coactivator that elicits many tolerance responses in chloroplasts and the nucleus. The transiently accumulated chloroplast NPR1 protein was translocated to the nucleus in a redox-dependent manner under salinity stress. In addition, immunoblotting and fluorescence image analysis showed that chloroplast-targeted NPR1-GFP fused with cTP (chloroplast transit peptide from RbcS) was localized in the nucleus during the responses to salt stress. Chloroplast functionality was essential for retrograde translocation, in which the stomules and cytoplasmic vesicles participated. Treatments with H2O2 and an ethylene precursor enhanced this retrograde translocation. Compared to each wild-type plant, retrograde signaling-related gene expression was severely impaired in the npr1-1 mutant in Arabidopsis, but enhanced transiently in the NPR1-Ox transgenic tobacco line. Therefore, NPR1 might be a retrograde signaling hub that improves a plant's adaptability to changing environments.

scholarly journals Dual-targeted transcription factors are required for optimal photosynthesis and stress responses in Arabidopsis thaliana

2019 ◽  
Author(s):  
Piotr Gawroński ◽  
Paweł Burdiak ◽  
Lars B. Scharff ◽  
Jakub Mielecki ◽  
Magdalena Zaborowska ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Stress Responses ◽  
Environmental Changes ◽  
Cell Function ◽  
Nuclear Gene ◽  
Transit Peptide ◽  
Protein Translation ◽  
Retrograde Signaling ◽  
Nuclear Gene Expression ◽  
Chloroplast Translation

SummaryChloroplast to nucleus retrograde signaling is essential for cell function, acclimation to fluctuating environmental conditions, plant growth and development. The vast majority of chloroplast proteins are nuclear-encoded and must be imported into the organelle after synthesis in the cytoplasm. This import is essential for the development of fully functional chloroplasts. On the other hand, functional chloroplasts act as sensors of environmental changes and can trigger acclimatory responses that influence nuclear gene expression. Signaling via mobile transcription factors (TFs) has been recently recognized as a way of communication between organelles and the nucleus. In this study, we performed a targeted reverse genetic screen to identify novel dual-localized TFs involved in chloroplast retrograde signaling during stress responses. We found that CHLOROPLAST IMPORT APPARATUS 2 (CIA2), a TF with putative plastid transit peptide can be detected in chloroplasts and the nucleus. Further, we found that CIA2, along with its homolog CIA2-like (CIL) act in an unequally redundant manner and are involved in the regulation of Arabidopsis responses to UV-AB, high light, and heat shock. Finally, our results suggest that both CIA2 and CIL are crucial for chloroplast translation. Our results contribute to a deeper understanding of signaling events in the chloroplast-nucleus cross-talk.SignificanceWe found that a transcription factor CIA2 can be located in chloroplasts and nucleus. CIA2 and is close homolog CIL are involved in protein translation and abiotic stress responses, and we suggest that they play an essential role in retrograde signaling between these organelles.

scholarly journals Association of transcription factor WRKY56 gene from Populus simonii × P. nigra with salt tolerance in Arabidopsis thaliana

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7291 ◽  
Author(s):  
Lei Wang ◽  
Wenjing Yao ◽  
Yao Sun ◽  
Jiying Wang ◽  
Tingbo Jiang
Keyword(s):  
Transcription Factor ◽  
Salt Stress ◽  
Abiotic Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Germination Rate ◽  
Wrky Transcription Factor ◽  
Biotic And Abiotic Stress ◽  
Populus Simonii ◽  
Reading Frame

The WRKY transcription factor family is one of the largest groups of transcription factor in plants, playing important roles in growth, development, and biotic and abiotic stress responses. Many WRKY genes have been cloned from a variety of plant species and their functions have been analyzed. However, the studies on WRKY transcription factors in tree species under abiotic stress are still not well characterized. To understand the effects of the WRKY gene in response to abiotic stress, mRNA abundances of 102 WRKY genes in Populus simonii × P. nigra were identified by RNA sequencing under normal and salt stress conditions. The expression of 23 WRKY genes varied remarkably, in a tissue-specific manner, under salt stress. Since the WRKY56 was one of the genes significantly induced by NaCl treatment, its cDNA fragment containing an open reading frame from P. simonii × P. nigra was then cloned and transferred into Arabidopsis using the floral dip method. Under salt stress, the transgenic Arabidopsis over-expressed the WRKY56 gene, showing an increase in fresh weight, germination rate, proline content, and peroxidase and superoxide dismutase activity, when compared with the wild type. In contrast, transgenic Arabidopsis displayed a decrease in malondialdehyde content under salt stress. Overall, these results indicated that the WRKY56 gene played an important role in regulating salt tolerance in transgenic Arabidopsis.

scholarly journals Jasmonic Acid Impairs Arabidopsis Seedling Salt Stress Tolerance Through MYC2-Mediated Repression of CAT2 Expression

2021 ◽  
Vol 12 ◽  
Author(s):  
Ru-Feng Song ◽  
Ting-Ting Li ◽  
Wen-Cheng Liu
Keyword(s):  
Salt Stress ◽  
Jasmonic Acid ◽  
Stress Tolerance ◽  
High Salinity ◽  
Vital Role ◽  
Plant Response ◽  
Wild Type Plant ◽  
Dependent Manner ◽  
Salt Stress Tolerance ◽  
Arabidopsis Seedling

High salinity causes ionic, osmotic, and oxidative stresses to plants, and the antioxidant enzyme Catalase2 (CAT2) plays a vital role in this process, while how CAT2 expression is regulated during plant response to high salinity remains elusive. Here, we report that phytohormone jasmonic acid (JA) impairs plant salt stress tolerance by repressing CAT2 expression in an MYC2-dependent manner. Exogenous JA application decreased plant salt stress tolerance while the jar1 mutant with reduced bioactive JA-Ile accumulation showed enhanced salt stress tolerance. JA enhanced salt-induced hydrogen peroxide (H2O2) accumulation, while treatment with H2O2-scavenger glutathione compromised such effects of JA on plant H2O2 accumulation and salt stress tolerance. In addition, JA repressed CAT2 expression in salt-stressed wild-type plant but not in myc2, a mutant of the master transcriptional factor MYC2 in JA signaling, therefore, the myc2 mutant exhibited increased salt stress tolerance. Further study showed that mutation of CAT2 largely reverted lower reactive oxygen species (ROS) accumulation, higher CAT activity, and enhanced salt stress tolerance of the myc2 mutant in myc2 cat2-1 double mutant, revealing that CAT2 functions downstream JA-MYC2 module in plant response to high salinity. Together, our study reveals that JA impairs Arabidopsis seedling salt stress tolerance through MYC2-mediated repression of CAT2 expression.

Overexpression of DnWRKY11 enhanced salt and drought stress tolerance of transgenic tobacco

Biologia ◽  
2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Xiang-Bin Xu ◽  
Yuan-Yuan Pan ◽  
Chun-Ling Wang ◽  
Qi-Cai Ying ◽  
Hong-Miao Song ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Tolerance ◽  
Transgenic Tobacco ◽  
Stress Responses ◽  
Environmental Changes ◽  
Germination Rate ◽  
Defense Responses ◽  
Biotic And Abiotic Stress ◽  
Field Environment

AbstractDendrobium seedlings showed low survival rate when they were transferred from in vitro conditions to greenhouse or field environment. One of the major reasons is their low tolerance to environmental changes. WRKY transcription factors are one of the largest families of transcriptional regulators in plants. They are involved in various biotic and abiotic stress responses. One DnWRKY11 gene was isolated from Dendrobium nobile. To explore the function of DnWRKY11 in Dendrobium defense responses to abiotic stress, it was overexpressed in tobacco. Under salt and drought stresses, the DnWRKY11 transgenic tobacco showed higher germination rate, longer root length, higher fresh weight, higher activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and lower content of malonidialdehyde (MDA) than the wild type. These results proved the important roles of DnWRKY11 in plant response to drought and salt stresses, and provided a potential gene for improving environmental stress tolerance of Dendrobium seedlings.

Identification of novel candidate phosphatidic acid-binding proteins involved in the salt-stress response of Arabidopsis thaliana roots

2013 ◽  
Vol 450 (3) ◽  
pp. 573-581 ◽  
Author(s):  
Fionn McLoughlin ◽  
Steven A. Arisz ◽  
Henk L. Dekker ◽  
Gertjan Kramer ◽  
Chris G. de Koster ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Stress ◽  
Phosphatidic Acid ◽  
Stress Responses ◽  
Ribosomal Proteins ◽  
Binding Proteins ◽  
Affinity Purification ◽  
Lipid Binding ◽  
Biotic And Abiotic Stress ◽  
Salt Stress Response

PA (phosphatidic acid) is a lipid second messenger involved in an array of processes occurring during a plant's life cycle. These include development, metabolism, and both biotic and abiotic stress responses. PA levels increase in response to salt, but little is known about its function in the earliest responses to salt stress. In the present study we have combined an approach to isolate peripheral membrane proteins of Arabidopsis thaliana roots with lipid-affinity purification, to identify putative proteins that interact with PA and are recruited to the membrane in response to salt stress. Of the 42 putative PA-binding proteins identified by MS, a set of eight new candidate PA-binding proteins accumulated at the membrane fraction after 7 min of salt stress. Among these were CHC (clathrin heavy chain) isoforms, ANTH (AP180 N-terminal homology) domain clathrin-assembly proteins, a putative regulator of potassium transport, two ribosomal proteins, GAPDH (glyceraldehyde 3-phosphate dehydrogenase) and a PI (phosphatidylinositol) 4-kinase. PA binding and salt-induced membrane recruitment of GAPDH and CHC were confirmed by Western blot analysis of the cellular fractions. In conclusion, the approach of the present study is an effective way to isolate biologically relevant lipid-binding proteins and provides new leads in the study of PA-mediated salt-stress responses in roots.

scholarly journals CRK2 enhances salt tolerance in Arabidopsis thaliana by regulating endocytosis and callose deposition in connection with PLDα1

2018 ◽  
Author(s):  
Kerri Hunter ◽  
Sachie Kimura ◽  
Anne Rokka ◽  
Cuong Tran ◽  
Masatsugu Toyota ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Subcellular Localization ◽  
Stress Responses ◽  
Negative Regulator ◽  
Biotic And Abiotic Stress ◽  
Callose Deposition ◽  
Receptor Like Kinase ◽  
Stress Dependent

AbstractHigh salinity has become an increasingly prevalent source of stress to which plants need to adapt. The receptor-like protein kinases (RLKs), including the cysteine-rich receptor-like kinase (CRK) subfamily, are a highly expanded family of transmembrane proteins in plants and are largely responsible for communication between cells and the extracellular environment. Various CRKs have been implicated in biotic and abiotic stress responses, however their functions on a cellular level remain largely uncharacterized. Here we have shown that CRK2 enhances salt tolerance at the germination stage in Arabidopsis thaliana. We identified CRK2 as a negative regulator of endocytosis, under both normal growth conditions and salt stress. We also established that functional CRK2 is required for salt-induced callose deposition. In doing so, we revealed a novel role for callose deposition, in response to increased salinity, and demonstrated its importance for salt tolerance during germination. Using fluorescently tagged proteins we observed specific changes in CRK2’s subcellular localization in response to various stress treatments. Many of CRK2’s cellular functions were dependent on phospholipase D (PLD) activity, as were the subcellular localization changes. Thus we propose that CRK2 acts downstream of PLD during salt stress to regulate endocytosis and promote callose deposition, and that CRK2 adopts specific stress-dependent subcellular localization patterns in order to carry out its functions.One sentence summaryThe receptor-like kinase CRK2 acts in connection with PLDα1 to regulate endocytosis and callose deposition at plasmodesmata, enhancing salt tolerance in Arabidopsis thaliana.

scholarly journals Genome-wide analysis of AP2/ERF Transcription Factors in sugarcane Saccharum spontaneum L. Reveals Functional Divergence During Drought, Salt Stress and Plant Hormones Treatment

2020 ◽  
Author(s):  
Piting Li ◽  
Zhe Chai ◽  
Pingping Lin ◽  
Chaohua Huang ◽  
Guoqiang Huang ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Salt Stress ◽  
Drought Stress ◽  
Stress Responses ◽  
Environmental Changes ◽  
Expression Patterns ◽  
Regulatory Elements ◽  
Structure Evolution ◽  
Saccharum Spontaneum ◽  
Erf Transcription Factors

Abstract Background: APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factors play important roles in plant growth, development, metabolism, as well as in biotic and abiotic stress responses. However, there are few studies concerning AP2/ERF genes in sugarcane, which is the most critical sugar and energy crop worldwide. Results: A total of 218 AP2/ERF genes were identified in the Saccharum spontaneum genome. Phylogenetic analysis showed that these genes could be divided into four groups, including 43 AP2s, 160 ERFs, and Dehydration-responsive element-binding (DREB) factors, 11 ABI3/VPs (RAV) and 4 Soloist genes. These genes were unevenly distributed on 32 chromosomes. Analysis of the structural of SsAP2/ERF genes showed that 91 SsAP2/ERFs lacked introns. Sugarcane and sorghum have a collinear relationship between 168 SsAP2/ERF genes and sorghum AP2/ERF genes that reflects their similarity. Multiple cis-regulatory elements (CREs) are present in the SsAP2/ERF promoter, and many are related to abiotic stresses, suggesting that SsAP2/ERF activity could contribute to the adaptation of sugarcane crops to environmental changes. The tissue-specific analysis showed spatiotemporal expression of SsAP2/ERF in the stems and leaves of sugarcane at different stages of development. In 10 sugarcane samples, 39 SsAP2/ERFs were not expressed at all, whereas 58 SsAP2/ERFs were expressed in all samples. Quantitative PCR experiments showed that SsERF52 expression was up-regulated under salt stress, but suppressed under drought stress. SsSoloist4 had the most considerable upregulation in response to treatment with the exogenous hormones ABA and GA. Within 3 hours of ABA or PEG6000 treatment, SsSoloist4 expression was up-regulated, indicating that this gene could play a role in ABA and GA-associated drought stress response mechanisms. Analysis of AP2/ERF gene expression patterns under different treatments indicated that SsAP2/ERF genes play an important role in drought and salt stress responses of S. spontaneum. Conclusions: In this study, a total of 218 members of the AP2 / ERF superfamily were identified in sugarcane, and their genetic structure, evolution characteristics, and expression patterns were studied and analyzed. The results of this study provide a foundation for future analyses to elucidate the importance of AP2/ERF transcription factors in the function and molecular breeding of sugarcane.

scholarly journals Membrane Lipid Remodeling in Response to Salinity

2019 ◽  
Vol 20 (17) ◽  
pp. 4264 ◽  
Author(s):  
Qi Guo ◽  
Lei Liu ◽  
Bronwyn J. Barkla
Keyword(s):  
Salt Stress ◽  
Stress Responses ◽  
Membrane Lipids ◽  
Signaling Molecules ◽  
Membrane Lipid ◽  
Biotic And Abiotic Stress ◽  
Comprehensive Overview ◽  
Plant Salt Tolerance ◽  
Induced Changes ◽  
Plant Membranes

Salinity is one of the most decisive environmental factors threatening the productivity of crop plants. Understanding the mechanisms of plant salt tolerance is critical to be able to maintain or improve crop yield under these adverse environmental conditions. Plant membranes act as biological barriers, protecting the contents of cells and organelles from biotic and abiotic stress, including salt stress. Alterations in membrane lipids in response to salinity have been observed in a number of plant species including both halophytes and glycophytes. Changes in membrane lipids can directly affect the properties of membrane proteins and activity of signaling molecules, adjusting the fluidity and permeability of membranes, and activating signal transduction pathways. In this review, we compile evidence on the salt stress responses of the major membrane lipids from different plant tissues, varieties, and species. The role of membrane lipids as signaling molecules in response to salinity is also discussed. Advances in mass spectrometry (MS)-based techniques have largely expanded our knowledge of salt-induced changes in lipids, however only a handful studies have investigated the underlying mechanisms of membrane lipidome regulation. This review provides a comprehensive overview of the recent works that have been carried out on lipid remodeling of plant membranes under salt treatment. Challenges and future perspectives in understanding the mechanisms of salt-induced changes to lipid metabolisms are proposed.

scholarly journals NDR1 and the Arabidopsis Plasma Membrane ATPase AHA5 are Required for Processes that Converge on Drought Tolerance and Immunity

2021 ◽  
Author(s):  
Yi-Ju Lu ◽  
Huan Chen ◽  
Alex Corrion ◽  
Pai Li ◽  
Ilker Buyuk ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Abiotic Stress ◽  
Stress Response ◽  
Pseudomonas Syringae ◽  
Stress Responses ◽  
Cell Biology ◽  
Dependent Manner ◽  
Abiotic Stress Response ◽  
Biotic And Abiotic Stress ◽  
Plasma Membrane Atpase

NON-RACE-SPECIFIC DISEASE RISISTANCE1 (NDR1) is a key component of plant immune signaling, required for defense against the bacterial pathogen Pseudomonas syringae. Plant stress responses have overlapping molecular, physiological, and cell biology signatures, and given the central role of NDR1 during biotic stress perception and signaling, we hypothesized that NDR1 also functions in abiotic stress responses, including in a role that mediates signaling at the plasma membrane (PM) - cell wall (CW) continuum. Here, we demonstrate that NDR1 is required for the induction of drought stress responses in plants, a role that couples stress signaling in an abscisic acid-dependent manner. We show that NDR1 physically associates with the PM-localized H+-ATPases AHA1, AHA2 , and AHA5 and is required for proper regulation of H+-ATPase activity and stomatal guard cell dynamics, providing a mechanistic function of NDR1 during drought responses. In the current study, we demonstrate that NDR1 functions in signaling processes associated with both biotic and abiotic stress response pathways, a function we hypothesize represents NDR1's role in the maintenance of cellular homeostasis during stress. We propose a role for NDR1 as a core transducer of signaling between cell membrane processes and intercellular stress response activation.

scholarly journals Enzymatic product formation impairs both the chloroplast receptor-binding function as well as translocation competence of the NADPH: protochlorophyllide oxidoreductase, a nuclear-encoded plastid precursor protein.

1995 ◽  
Vol 129 (2) ◽  
pp. 299-308 ◽  
Author(s):  
S Reinbothe ◽  
C Reinbothe ◽  
S Runge ◽  
K Apel
Keyword(s):  
Aminolevulinic Acid ◽  
Transit Peptide ◽  
Precursor Protein ◽  
Receptor Protein ◽  
Chloroplast Envelope ◽  
Dependent Manner ◽  
Envelope Membrane ◽  
Chloroplast Transit Peptide ◽  
Plastid Envelope

The key enzyme of chlorophyll biosynthesis in higher plants, the light-dependent NADPH:protochlorophyllide oxidoreductase (POR, EC 1.6.99.1), is a nuclear-encoded plastid protein. Its posttranslational transport into plastids of barley depends on the intraplastidic availability of one of its substrates, protochlorophyllide (PChlide). The precursor of POR (pPOR), synthesized from a corresponding full-length barley cDNA clone by coupling in vitro transcription and translation, is enzymatically active and converts PChlide to chlorophyllide (Chlide) in a light- and NADPH-dependent manner. Chlorophyllide formed catalytically remains tightly but noncovalently bound to the precursor protein and stabilizes a transport-incompetent conformation of pPOR. As shown by in vitro processing experiments, the chloroplast transit peptide in the Chlide-pPOR complex appears to be masked and thus is unable to physically interact with the outer plastid envelope membrane. In contrast, the chloroplast transit peptide in the naked pPOR (without its substrates and its product attached to it) and in the pPOR-substrate complexes, such as pPOR-PChlide or pPOR-PChlide-NADPH, seems to react independently of the mature region of the polypeptide, and thus is able to bind to the plastid envelope. When envelope-bound pPOR-PChlide-NADPH complexes were exposed to light during a short preincubation, the enzymatically produced Chlide slowed down the actual translocation step, giving rise to the sequential appearance of two partially processed translocation intermediates. However, ongoing translocation induced by feeding the chloroplasts delta-aminolevulinic acid, a precursor of PChlide, was able to override these two early blocks in translocation, suggesting that the plastid import machinery has a substantial capacity to denature a tightly folded, envelope-bound precursor protein. Together, our results show that pPOR with Chlide attached to it is impaired both in the ATP-dependent step of binding to a receptor protein component of the outer chloroplast envelope membrane, as well as in the PChlide-dependent step of precursor translocation.

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