scholarly journals Low Mannitol Concentrations in Arabidopsis thaliana Expressing Ectocarpus Genes Improve Salt Tolerance

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1508
Author(s):  
Pramod Rathor ◽  
Tudor Borza ◽  
Yanhui Liu ◽  
Yuan Qin ◽  
Sophia Stone ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Tolerance ◽  
Transgenic Plants ◽  
Salinity Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Ion Homeostasis ◽  
Biotic And Abiotic Stress ◽  
Expression Of Genes ◽  
Wide Range

Mannitol is abundant in a wide range of organisms, playing important roles in biotic and abiotic stress responses. Nonetheless, mannitol is not produced by a vast majority of plants, including many important crop plants. Mannitol-producing transgenic plants displayed improved tolerance to salt stresses though mannitol production was rather low, in the µM range, compared to mM range found in plants that innately produce mannitol. Little is known about the molecular mechanisms underlying salt tolerance triggered by low concentrations of mannitol. Reported here is the production of mannitol in Arabidopsis thaliana, by expressing two mannitol biosynthesis genes from the brown alga Ectocarpus sp. strain Ec32. To date, no brown algal genes have been successfully expressed in land plants. Expression of mannitol-1-phosphate dehydrogenase and mannitol-1-phosphatase genes was associated with the production of 42.3–52.7 nmol g−1 fresh weight of mannitol, which was sufficient to impart salinity and temperature stress tolerance. Transcriptomics revealed significant differences in the expression of numerous genes, in standard and salinity stress conditions, including genes involved in K+ homeostasis, ROS signaling, plant development, photosynthesis, ABA signaling and secondary metabolism. These results suggest that the improved tolerance to salinity stress observed in transgenic plants producing mannitol in µM range is achieved by the activation of a significant number of genes, many of which are involved in priming and modulating the expression of genes involved in a variety of functions including hormone signaling, osmotic and oxidative stress, and ion homeostasis.

Balancing salinity stress responses in halophytes and non-halophytes: a comparison between Thellungiella and Arabidopsis thaliana

2013 ◽  
Vol 40 (9) ◽  
pp. 819 ◽  
Author(s):  
Dorothea Bartels ◽  
Challabathula Dinakar
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Light Stress ◽  
Stress Factors ◽  
Natural Environments ◽  
Terrestrial Plants ◽  
Abiotic Stress Factors

Salinity is one of the major abiotic stress factors that drastically reduces agricultural productivity. In natural environments salinity often occurs together with other stresses such as dehydration, light stress or high temperature. Plants cope with ionic stress, dehydration and osmotic stress caused by high salinity through a variety of mechanisms at different levels involving physiological, biochemical and molecular processes. Halophytic plants exist successfully in stressful saline environments, but most of the terrestrial plants including all crop plants are glycophytes with varying levels of salt tolerance. An array of physiological, structural and biochemical adaptations in halophytes make them suitable models to study the molecular mechanisms associated with salinity tolerance. Comparative analysis of plants that differ in their abilities to tolerate salinity will aid in better understanding the phenomenon of salinity tolerance. The halophyte Thellungiella salsuginea has been used as a model for studying plant salt tolerance. In this review, T. salsuginea and the glycophyte Arabidopsis thaliana are compared with regards to their biochemical, physiological and molecular responses to salinity. In addition recent developments are presented for improvement of salinity tolerance in glycophytic plants using genes from halophytes.

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 Analysis of Seaweed Extract-induced Transcriptome Leads to Identification of a Negative Regulator of Salt Tolerance in Arabidopsis

HortScience ◽  
2012 ◽  
Vol 47 (6) ◽  
pp. 704-709 ◽  
Author(s):  
Mundaya N. Jithesh ◽  
Owen S.D. Wally ◽  
Iain Manfield ◽  
Alan T. Critchley ◽  
David Hiltz ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Salinity Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Primary Root ◽  
Brown Seaweed ◽  
Nacl Stress ◽  
Negative Regulator ◽  
Insertion Mutant ◽  
Dna Insertion

Successful development of plants resistant to salinity stress is problematic as a result of the complex polygenic natures of salt tolerance. Previously, alkaline extracts of the brown seaweed Ascophyllum nodosum have shown promise in enhancing plant tolerance toward abiotic stresses. To understand the underlying molecular mechanisms, the whole genome transcriptome of Arabidopsis undergoing salt stress was analyzed by microarray analysis after treatment with the chemical components of A. nodosum extracts (ANE). Treatment with ANE induced many positive regulators of salt tolerance in addition to downregulating numerous other genes. Using T-DNA insertion mutants within these downregulated genes, we examined the potential for a novel source of enhanced NaCl tolerance through removal of negative regulators of NaCl stress responses within Arabidopsis. Several potential target mutations were identified with enhanced salt-tolerant phenotypes. A T-DNA insertion within the promoter of a putative Pectin Methyl Esterase Inhibitor (PMEI) gene (At1g62760) was found to be resistant to salinity stress and was further characterized. This T-DNA insertion mutant was designated as pmei1-1. The phenotype of pmei1-1 seedlings included increased primary root growth in vitro and improved biomass accumulation under NaCl stress. Additionally, modified transcript levels of dehydration-responsive genes, including RD29A, were observed in pmei1-1 plants. Taken together, these results suggest a role for PMEI as a negative regulator of NaCl resistance and that chemical stress-induced transcriptome analysis may lead to identification of additional novel regulators of abiotic stress tolerance in plants, the use of which would have significant implications for agriculture globally.

scholarly journals Arabidopsis heat shock transcription factor HSFA7b positively mediates salt stress tolerance by binding to an E-box-like motif to regulate gene expression

2019 ◽  
Vol 70 (19) ◽  
pp. 5355-5374 ◽  
Author(s):  
Dandan Zang ◽  
Jingxin Wang ◽  
Xin Zhang ◽  
Zhujun Liu ◽  
Yucheng Wang
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Heat Shock ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Ion Homeostasis ◽  
Cellulose Synthase ◽  
Regulate Gene Expression ◽  
E Box ◽  
Regulate Gene

Abstract Plant heat shock transcription factors (HSFs) are involved in heat and other abiotic stress responses. However, their functions in salt tolerance are little known. In this study, we characterized the function of a HSF from Arabidopsis, AtHSFA7b, in salt tolerance. AtHSFA7b is a nuclear protein with transactivation activity. ChIP-seq combined with an RNA-seq assay indicated that AtHSFA7b preferentially binds to a novel cis-acting element, termed the E-box-like motif, to regulate gene expression; it also binds to the heat shock element motif. Under salt conditions, AtHSFA7b regulates its target genes to mediate serial physiological changes, including maintaining cellular ion homeostasis, reducing water loss rate, decreasing reactive oxygen species accumulation, and adjusting osmotic potential, which ultimately leads to improved salt tolerance. Additionally, most cellulose synthase-like (CSL) and cellulose synthase (CESA) family genes were inhibited by AtHSFA7b; some of them were randomly selected for salt tolerance characterization, and they were mainly found to negatively modulate salt tolerance. By contrast, some transcription factors (TFs) were induced by AtHSFA7b; among them, we randomly identified six TFs that positively regulate salt tolerance. Thus, AtHSFA7b serves as a transactivator that positively mediates salinity tolerance mainly through binding to the E-box-like motif to regulate gene expression.

scholarly journals Overexpression of SgGH3.1 from Fine-Stem Stylo (Stylosanthes guianensis var. intermedia) Enhances Chilling and Cold Tolerance in Arabidopsis thaliana

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1367
Author(s):  
Ming Jiang ◽  
Long-Long Ma ◽  
Huai-An Huang ◽  
Shan-Wen Ke ◽  
Chun-Sheng Gui ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cold Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Transcriptome Profiling ◽  
Pasture Legumes ◽  
Cold Tolerant ◽  
Whole Transcriptome ◽  
Altered Sensitivity ◽  
Exogenous Iaa

Stylosanthes (stylo) species are commercially significant tropical and subtropical forage and pasture legumes that are vulnerable to chilling and frost. However, little is known about the molecular mechanisms behind stylos’ responses to low temperature stress. Gretchen-Hagen 3 (GH3) proteins have been extensively investigated in many plant species for their roles in auxin homeostasis and abiotic stress responses, but none have been reported in stylos. SgGH3.1, a cold-responsive gene identified in a whole transcriptome profiling study of fine-stem stylo (S. guianensis var. intermedia) was further investigated for its involvement in cold stress tolerance. SgGH3.1 shared a high percentage of identity with 14 leguminous GH3 proteins, ranging from 79% to 93%. Phylogenetic analysis classified SgGH3.1 into Group Ⅱ of GH3 family, which have been proven to involve with auxins conjugation. Expression profiling revealed that SgGH3.1 responded rapidly to cold stress in stylo leaves. Overexpression of SgGH3.1 in Arabidopsis thaliana altered sensitivity to exogenous IAA, up-regulated transcription of AtCBF1-3 genes, activated physiological responses against cold stress, and enhanced chilling and cold tolerances. This is the first report of a GH3 gene in stylos, which not only validated its function in IAA homeostasis and cold responses, but also gave insight into breeding of cold-tolerant stylos.

scholarly journals Early life adversity and the epigenetic programming of hypothalamic-pituitary-adrenal function

2014 ◽  
Vol 16 (3) ◽  
pp. 321-333 ◽  
Keyword(s):  
Stress Responses ◽  
Childhood Adversity ◽  
Adrenal Function ◽  
Early Life Adversity ◽  
Hypothalamic Pituitary Adrenal ◽  
Expression Of Genes ◽  
Epigenetic Programming ◽  
Social Adversity ◽  
Wide Range ◽  
Nonhuman Species

We review studies with human and nonhuman species that examine the hypothesis that epigenetic mechanisms, particularly those affecting the expression of genes implicated in stress responses, mediate the association between early childhood adversity and later risk of depression. The resulting studies provide evidence consistent with the idea that social adversity, particularly that involving parent-offspring interactions, alters the epigenetic state and expression of a wide range of genes, the products of which regulate hypothalamic-pituitary-adrenal function. We also address the challenges for future studies, including that of the translation of epigenetic studies towards improvements in treatments.

scholarly journals Long non-coding RNAs in plants: emerging modulators of gene activity in development and stress responses

Planta ◽  
2020 ◽  
Vol 252 (5) ◽  
Author(s):  
Li Chen ◽  
Qian-Hao Zhu ◽  
Kerstin Kaufmann
Keyword(s):  
Stress Responses ◽  
Translational Regulation ◽  
Molecular Mechanisms ◽  
Functional Characterization ◽  
Reproductive Organs ◽  
Gene Activity ◽  
Protein Coding ◽  
Wide Range ◽  
Non Coding Rnas ◽  
Coding Potential

Abstract Main conclusion Long non-coding RNAs modulate gene activity in plant development and stress responses by various molecular mechanisms. Abstract Long non-coding RNAs (lncRNAs) are transcripts larger than 200 nucleotides without protein coding potential. Computational approaches have identified numerous lncRNAs in different plant species. Research in the past decade has unveiled that plant lncRNAs participate in a wide range of biological processes, including regulation of flowering time and morphogenesis of reproductive organs, as well as abiotic and biotic stress responses. LncRNAs execute their functions by interacting with DNA, RNA and protein molecules, and by modulating the expression level of their targets through epigenetic, transcriptional, post-transcriptional or translational regulation. In this review, we summarize characteristics of plant lncRNAs, discuss recent progress on understanding of lncRNA functions, and propose an experimental framework for functional characterization.

scholarly journals Signal Integration in Plant Abiotic Stress Responses via Multistep Phosphorelay Signaling

2021 ◽  
Vol 12 ◽  
Author(s):  
Jan Skalak ◽  
Katrina Leslie Nicolas ◽  
Radomira Vankova ◽  
Jan Hejatko
Keyword(s):  
Abiotic Stress ◽  
Stress Responses ◽  
Environmental Conditions ◽  
Molecular Mechanisms ◽  
Geographical Location ◽  
Survival Strategies ◽  
Balance Growth ◽  
Adaptive Responses ◽  
Wide Range ◽  
Sensor Kinases

Plants growing in any particular geographical location are exposed to variable and diverse environmental conditions throughout their lifespan. The multifactorial environmental pressure resulted into evolution of plant adaptation and survival strategies requiring ability to integrate multiple signals that combine to yield specific responses. These adaptive responses enable plants to maintain their growth and development while acquiring tolerance to a variety of environmental conditions. An essential signaling cascade that incorporates a wide range of exogenous as well as endogenous stimuli is multistep phosphorelay (MSP). MSP mediates the signaling of essential plant hormones that balance growth, development, and environmental adaptation. Nevertheless, the mechanisms by which specific signals are recognized by a commonly-occurring pathway are not yet clearly understood. Here we summarize our knowledge on the latest model of multistep phosphorelay signaling in plants and the molecular mechanisms underlying the integration of multiple inputs including both hormonal (cytokinins, ethylene and abscisic acid) and environmental (light and temperature) signals into a common pathway. We provide an overview of abiotic stress responses mediated via MSP signaling that are both hormone-dependent and independent. We highlight the mutual interactions of key players such as sensor kinases of various substrate specificities including their downstream targets. These constitute a tightly interconnected signaling network, enabling timely adaptation by the plant to an ever-changing environment. Finally, we propose possible future directions in stress-oriented research on MSP signaling and highlight its potential importance for targeted crop breeding.

scholarly journals Transcriptome Analysis of Four Arabidopsis thaliana Mediator Tail Mutants Reveals Overlapping and Unique Functions in Gene Regulation

2018 ◽  
Author(s):  
Whitney L. Dolan ◽  
Clint Chapple
Keyword(s):  
Arabidopsis Thaliana ◽  
Global Gene Expression ◽  
Future Research ◽  
Central Component ◽  
Biotic And Abiotic Stress ◽  
Expression Of Genes ◽  
Structural Relationships ◽  
Individual Contributions ◽  
The Individual ◽  
The Impact

ABSTRACTThe Mediator complex is a central component of transcriptional regulation in Eukaryotes. The complex is structurally divided into four modules known as the head, middle, tail and kinase modules, and in Arabidopsis thaliana, comprises 28-34 subunits. Here, we explore the functions of four Arabidopsis Mediator tail subunits, MED2, MED5a/b, MED16, and MED23, by comparing the impact of mutations in each on the Arabidopsis transcriptome. We find that these subunits affect both unique and overlapping sets of genes, providing insight into the functional and structural relationships between them. The mutants primarily exhibit changes in the expression of genes related to biotic and abiotic stress. We find evidence for a tissue specific role for MED23, as well as in the production of alternative transcripts. Together, our data help disentangle the individual contributions of these MED subunits to global gene expression and suggest new avenues for future research into their functions.

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.

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