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Steffen P. Graether - One of the best experts on this subject based on the ideXlab platform.

  • Binding of a Vitis riparia Dehydrin to DNA
    Plant science : an international journal of experimental plant biology, 2019
    Co-Authors: Kelly F. Boddington, Steffen P. Graether
    Abstract:

    Abstract Plants must protect themselves from abiotic stresses such as drought, cold, and high salinity. The common thread of all three stresses is that they cause dehydration, which in turn promotes the formation of reactive oxygen species (ROS). Dehydrin proteins (Dehydrins) are a large family of proteins that have been identified in nearly all land plants, and whose presence is correlated with plant protection from abiotic stresses. Several Dehydrin studies have shown that some Dehydrins localize to the nucleus, as well as the cytoplasm, but a functional role for nuclear Dehydrins has not yet been determined. We show here that the Vitis riparia Dehydrin VrDHN1 localizes to the nucleus and is able to bind to DNA to protect it from damage caused by hydrogen peroxide, an ROS source. We also show that the binding to DNA is not DNA-sequence specific, suggesting that the protein is able to protect any exposed DNA without interfering with its normal function. NMR studies show that the binding is largely driven by the lysine-rich nature of Dehydrins located in the conserved K-segments. Unlike other, previously studied Dehydrins, VrDHN1 binding to DNA is not enhanced through the presence of metals. Lastly, we demonstrate that the Y-segment does not bind ATP, as has long been proposed.

  • Evolution of the modular, disordered stress proteins known as Dehydrins
    2019
    Co-Authors: Andrew C. Riley, Daniel A. Ashlock, Steffen P. Graether
    Abstract:

    Dehydrins, plant proteins that are upregulated during dehydration stress conditions, have modular sequences that can contain three conserved motifs (the Y-, S-, and K-segments). The presence and order of these motifs are used to classify Dehydrins into one of five architectures: Kn, SKn, KnS, YnKn, and YnSKn, where the subscript n describes the number of copies of that motif. In this study, an architectural and phylogenetic analysis was performed on 426 Dehydrin sequences that were identified in 53 angiosperm and 3 gymnosperm genomes. It was found that angiosperms contained all five architectures, while gymnosperms only contained Kn and SKn Dehydrins. This suggests that the ancestral Dehydrin in spermatophytes was either Kn or SKn, and the Y-segment containing Dehydrins first arose in angiosperms. A high-level split between the YnSKn Dehydrins from either the Kn or SKn Dehydrins could not be confidently identified, however, two lower level architectural divisions appear to have occurred after different duplication events. The first likely occurred after a whole genome duplication, resulting in the duplication of a Y3SK2 Dehydrin; the duplicate subsequently lost an S- and K- segment to become a Y3K1 Dehydrin. The second split occurred after a tandem duplication of a Y1SK2 Dehydrin, where the duplicate lost both the Y- and S- segment and gained four K-segments, resulting in a K6 Dehydrin. We suggest that the newly arisen Y3K1 Dehydrin is possibly on its way to pseudogenization, while the newly arisen K6 Dehydrin developed a novel function in cold protection.

  • Genome Analysis of Conserved Dehydrin Motifs in Vascular Plants.
    Frontiers in plant science, 2017
    Co-Authors: Ahmad A. Malik, Kelly F. Boddington, Michael Veltri, Karamjeet K. Singh, Steffen P. Graether
    Abstract:

    Dehydrins, a large family of abiotic stress proteins, are defined by the presence of a mostly conserved motif known as the K-segment, and may also contain two other conserved motifs known as the Y-segment and S-segment. Using the Dehydrin literature, we developed a sequence motif definition of the K-segment, which we used to create a large dataset of Dehydrin sequences by searching the Pfam00257 Dehydrin dataset and the Phytozome 10 sequences of vascular plants. A comprehensive analysis of these sequences reveals that lysine residues are highly conserved in the K-segment, while the amino acid type is often conserved at other positions. Despite the Y-segment name, the central tyrosine is somewhat conserved, but can be substituted with two other small aromatic amino acids (phenylalanine or histidine). The S-segment contains a series of serine residues, but in some proteins is also preceded by a conserved LHR sequence. In many Dehydrins containing all three of these motifs the S-segment is linked to the K-segment by a GXGGRRKK motif (where X can be any amino acid), suggesting a functional linkage between these two motifs. An analysis of the sequences shows that the Dehydrin architecture and several biochemical properties (isoelectric point, molecular mass and hydrophobicity score) are dependent on each other, and that some Dehydrin architectures are overexpressed during certain abiotic stress, suggesting that they may be optimized for a specific abiotic stress while others are involved in all forms of dehydration stress (drought, cold and salinity).

  • Disorder and function: a review of the Dehydrin protein family.
    Frontiers in plant science, 2014
    Co-Authors: Steffen P. Graether, Kelly F. Boddington
    Abstract:

    Dehydration proteins (Dehydrins) are group 2 members of the late embryogenesis abundant (LEA) protein family. The protein architecture of Dehydrins can be described by the presence of three types of conserved sequence motifs that have been named the K-, Y-, and S-segments. By definition, a Dehydrin must contain at least one copy of the lysine-rich K-segment. Abiotic stresses such as drought, cold, and salinity cause the upregulation of Dehydrin mRNA and protein levels. Despite the large body of genetic and protein evidence of the importance of these proteins in stress response, the in vivo protective mechanism is not fully known. In vitro experimental evidence from biochemical assays and localization experiments suggests multiple roles for Dehydrins, including membrane protection, cryoprotection of enzymes, and protection from reactive oxygen species. Membrane binding by Dehydrins is likely to be as a peripheral membrane protein, since the protein sequences are highly hydrophilic and contain many charged amino acids. Because of this, Dehydrins in solution are intrinsically disordered proteins, that is, they have no well-defined secondary or tertiary structure. Despite their disorder, Dehydrins have been shown to gain structure when bound to ligands such as membranes, and to possibly change their oligomeric state when bound to ions. We review what is currently known about Dehydrin sequences and their structures, and examine the various ligands that have been shown to bind to this family of proteins.

  • a Dehydrin Dehydrin interaction the case of sk3 from opuntia streptacantha
    Frontiers in Plant Science, 2014
    Co-Authors: Itzell E Hernandezsanchez, Steffen P. Graether, David M. Martynowicz, Aida Araceli Rodriguezhernandez, Maria B Perezmorales, Juan Francisco Jimenezbremont
    Abstract:

    Dehydrins belongs to a large group of highly hydrophilic proteins known as Late Embryogenesis Abundant (LEA) proteins. It is well know that Dehydrins are intrinsically disordered plant proteins that accumulate during the late stages of embryogenesis and in response to abiotic stresses; however, the molecular mechanisms by which their functions are carried out are still unclear. We have previously reported that transgenic Arabidopsis plants overexpressing an Opuntia streptacantha SK3 Dehydrin (OpsDHN1) show enhanced tolerance to freezing stress. Herein, we show using a split-ubiquitin yeast two-hybrid system that OpsDHN1 dimerizes. We found that the deletion of regions containing K-segments and the histidine-rich region in the OpsDHN1 protein affects dimer formation. Not surprisingly, in silico protein sequence analysis suggests that OpsDHN1 is an intrinsically disordered protein, an observation that was confirmed by circular dichroism and gel filtration of the recombinantly expressed protein. The addition of zinc triggered the association of recombinantly expressed OpsDHN1 protein, likely through its histidine-rich motif. These data brings new insights about the molecular mechanism of the OpsDHN1 SK3-Dehydrin

Timothy J. Close - One of the best experts on this subject based on the ideXlab platform.

  • purification and partial characterization of a Dehydrin involved in chilling tolerance during seedling emergence of cowpea
    Plant Physiology, 1999
    Co-Authors: Abdelbagi M Ismail, Anthony E Hall, Timothy J. Close
    Abstract:

    Dehydrins are a family of proteins (LEA [late-embryogenesis abundant] D11) commonly induced by environmental stresses associated with low temperature or dehydration and during seed maturation drying. Our previous genetic studies suggested an association of an approximately 35-kD protein (by immunological evidence a Dehydrin) with chilling tolerance during emergence of seedlings of cowpea (Vigna unguiculata) line 1393-2-11. In the present study we found that the accumulation of this protein in developing cowpea seeds is coordinated with the start of the dehydration phase of embryo development. We purified this protein from dry seeds of cowpea line 1393-2-11 by using the characteristic high-temperature solubility of Dehydrins as an initial enrichment step, which was followed by three chromatography steps involving cation exchange, hydrophobic interaction, and anion exchange. Various characteristics of this protein confirmed that indeed it is a Dehydrin, including total amino acid composition, partial amino acid sequencing, and the adoption of α-helical structure in the presence of sodium dodecyl sulfate. The propensity of Dehydrins to adopt α-helical structure in the presence of sodium dodecyl sulfate, together with the apparent polypeptide adhesion property of this cowpea Dehydrin, suggests a role in stabilizing other proteins or membranes. Taken together, the genetic, physiological, and physicochemical data are at this stage consistent with a cause-and-effect relationship between the presence in mature seeds of the approximately 35-kD Dehydrin, which is the product of a single member of a multigene family, and an increment of chilling tolerance during emergence of cowpea seedlings.

  • purification immunolocalization cryoprotective and antifreeze activity of pca60 a Dehydrin from peach prunus persica
    Physiologia Plantarum, 1999
    Co-Authors: Michael Wisniewski, Timothy J. Close, Ron Balsamo, Robert Webb, Marilyn Griffith
    Abstract:

    Dehydrins are glycine-rich, hydrophilic, heat-stable proteins and are generally induced in response to a wide array of environmental stresses. In previous research (Artlip et al. 1997, Plant Molecular Biology 33: 61-70), a full-length Dehydrin gene, ppdhn1, was isolated from peach, and its expression was associated with qualitative and quantitative differences in cold hardiness in sibling genotypes of evergreen and deciduous peach. Similar results were obtained for levels of the corresponding 60 kDa peach Dehydrin protein (PCA60). The objective of the present study was to purify the PCA60, test the purified protein for cryoprotective and/or antifreeze activity, and to determine the cellular localization of PCA60 using immunomicroscopy. PCA60 was extracted from winter bark tissues of peach (Prunus persica [L.] Batsch) and purified in a two-step process. Separation was based on free-solution isoelectric focusing followed by size exclusion. Purified PCA60, as well as crude protein extract, preserved the in vitro enzymatic activity of lactate dehydrogenase after several freeze-thaw cycles in liquid nitrogen. PCA also exhibited distinct antifreeze activity as evidenced by ice crystal morphology and thermal hysteresis. This is the first time antifreeze activity has been demonstrated for Dehydrins. Immunomicroscopy, utilizing an affinity-purified, polyclonal antibody developed against a synthetic peptide of the lysine-rich consensus portion of Dehydrins, indicated that PCA60 was freely distributed in the cytoplasm, plastids, and nucleus of bark cells and xylem parenchyma cells. Although the functional role of Dehydrins remains speculative, the data support the hypothesis that it plays a role in preventing denaturation of proteins exposed to dehvdrative stresses.

  • genetic studies of triticeae Dehydrins assignment of seed proteins and a regulatory factor to map positions
    Theoretical and Applied Genetics, 1998
    Co-Authors: J E Wernerfraczek, Timothy J. Close
    Abstract:

    A collection of 200 wheat (Triticum aestivum L. cv ‘Chinese Spring’) cytogenetic stocks (nullisomic, tetrasomic, nulli-tetrasomic, ditelosomic and deletion lines, addition and substitution stocks from intra- and inter-specific crosses) was utilized to determine the proteins encoded by some of the wheat and barley Dehydrin genes, using a western blot procedure. Proteins extracted from seeds were reacted with antibodies that recognize Dehydrins in a wide range of plants, including wheat and barley. Proteins encoded by Dehydrin loci in chromosome arms 4DS, 5BL and 6AL of ‘Chinese Spring’ wheat were assigned by this method. There was also evidence of a regulatory factor on 5B in the vicinity of the dhn genes, and on 5H in wheat-barley addition lines, that is required for a normal level of expression of seed Dehydrins in hexaploid wheat. Further understanding of this putative regulatory factor would be helpful for the interpretation of linkage studies that may relate Dehydrin gene expression to phenotypes such as dehydration, salinity or low-temperature tolerance.

  • Dehydrins: genes, proteins, and associations with phenotypic traits
    New Phytologist, 1997
    Co-Authors: Scott A. Campbell, Timothy J. Close
    Abstract:

    Dehydrin proteins (late embryogenesis abundant (LEA) D11 family) are produced in a wide variety of plant species in response to environmental stimuli with a dehydrative component, including drought, low temperature, salinity, and developmental stages such as seed and pollen maturation. Despite their widespread occurrence and abundance in cells under dehydrative conditions, the biochemical role of Dehydrins remains elusive. The subcellular location of Dehydrins is consistent with a biochemical role as an intracellular stabilizer, possibly with surfactant characteristics, acting upon targets in both the nucleus and cytoplasm. In some species, Dehydrin loci are located within quantitative trait loci (QTL) intervals for important phenotypic traits including winter hardiness in barley (Hordeum vulgare L.) and anthesis-silking interval in maize (Zea mays L.). Dehydrin loci tend to be multigenic and occur in clusters on more than one chromosome. Investigations are currently under way in our laboratory and others' to move beyond protein accumulation studies and correlations with QTL to uncover direct cause-and-effect relationships between Dehydrin (dhn) genes and phenotypes associated with physiological responses to stress.

  • Temporal accumulation and ultrastructural localization of Dehydrins in Zea mays
    Physiologia Plantarum, 1997
    Co-Authors: Louise M. Egerton-warburton, Ronald A. Balsamo, Timothy J. Close
    Abstract:

    Immunolocalization using polyclonal antibodies raised against a conserved Dehydrin amino acid sequence was used to establish the temporal and spatial patterns of Dehydrin accumulation in embryo tissue of Zea mays L. (var. Ohio 43) kernels imbibed in the presence of abscisic acid. The temporal pattern of accumulation indicated an increase in Dehydrins over time (particularly between 15 and 30 h) and with maximum levels detected 48 h after the onset of imbibition. Dehydrins were first evident, and also the most concentrated, in the cytosol throughout the accumulation period suggesting that the primary function of Dehydrins involves the cytosol and the structures contained therein. Only after an accumulation of Dehydrins in the cytosol was there an increase in the abundance of nuclear Dehydrins. In addition, Dehydrins were also observed in association with the proteinaceous matrix of protein bodies and membranes of protein and lipid bodies; these findings have not been reported previously. The observed localization at a number of sites indicates that the specific biochemical roles of Dehydrins are likely to be diverse.

Ilja Tom Prášil - One of the best experts on this subject based on the ideXlab platform.

  • Relationship Between Dehydrin Accumulation and Winter Survival in Winter Wheat and Barley Grown in the Field
    Frontiers Media S.A., 2019
    Co-Authors: Pavel Vítámvás, Klára Kosová, Jana Musilová, Ludmila Holková, Pavel Mařík, Pavlína Smutná, Miroslav Klíma, Ilja Tom Prášil
    Abstract:

    Low temperatures represent a crucial environmental factor determining winter survival (WS) of barley and wheat winter-type varieties. In laboratory experiments, low temperatures induce an active plant acclimation response, which is associated with an enhanced accumulation of several stress-inducible proteins including Dehydrins. Here, Dehydrin accumulations in sampled wheat (WCS120 protein family, or WCS120 and WDHN13 transcripts) and barley (DHN5 protein) varieties grown in two locations for two winters were compared with the variety WS evaluated by a provocation wooden-box test. A high correlation between Dehydrin transcripts or protein relative accumulation and variety WS score was found only in samples taken prior vernalization fulfillment, when high tolerant varieties accumulated Dehydrins earlier and to higher level than less tolerant varieties, and the plants have not yet been vernalized. After vernalization fulfillment, the correlation was weak, and the apical development indicated that plants reached double ridge (DR) in barley or stayed before DR in wheat. Dehydrin proteins and transcripts can be thus used as reliable markers of wheat or barley variety winter hardiness in the field conditions; however, only at the beginning of winter, when the plants have not yet finished vernalization. In wheat, a higher correlation was obtained for the total amount of Dehydrins than for the individual Dehydrin proteins.HIGHLIGHTS-More tolerant winter-type wheat and barley plants reveal higher threshold induction temperatures for Dehydrin accumulation in comparison to less tolerant varieties. Thus, more tolerant winter cereals have higher Dehydrin levels than the less tolerant ones upon the same ambient temperature in November samplings.-A significant correlation between Dehydrin transcript/protein accumulation and winter survival was found in both winter wheat and winter barley plants in the field conditions, but only prior to vernalization fulfillment

  • Data_Sheet_1_Relationship Between Dehydrin Accumulation and Winter Survival in Winter Wheat and Barley Grown in the Field.docx
    2019
    Co-Authors: Pavel Vítámvás, Klára Kosová, Jana Musilová, Ludmila Holková, Pavel Mařík, Pavlína Smutná, Miroslav Klíma, Ilja Tom Prášil
    Abstract:

    Low temperatures represent a crucial environmental factor determining winter survival (WS) of barley and wheat winter-type varieties. In laboratory experiments, low temperatures induce an active plant acclimation response, which is associated with an enhanced accumulation of several stress-inducible proteins including Dehydrins. Here, Dehydrin accumulations in sampled wheat (WCS120 protein family, or WCS120 and WDHN13 transcripts) and barley (DHN5 protein) varieties grown in two locations for two winters were compared with the variety WS evaluated by a provocation wooden-box test. A high correlation between Dehydrin transcripts or protein relative accumulation and variety WS score was found only in samples taken prior vernalization fulfillment, when high tolerant varieties accumulated Dehydrins earlier and to higher level than less tolerant varieties, and the plants have not yet been vernalized. After vernalization fulfillment, the correlation was weak, and the apical development indicated that plants reached double ridge (DR) in barley or stayed before DR in wheat. Dehydrin proteins and transcripts can be thus used as reliable markers of wheat or barley variety winter hardiness in the field conditions; however, only at the beginning of winter, when the plants have not yet finished vernalization. In wheat, a higher correlation was obtained for the total amount of Dehydrins than for the individual Dehydrin proteins.HIGHLIGHTS-More tolerant winter-type wheat and barley plants reveal higher threshold induction temperatures for Dehydrin accumulation in comparison to less tolerant varieties. Thus, more tolerant winter cereals have higher Dehydrin levels than the less tolerant ones upon the same ambient temperature in November samplings.-A significant correlation between Dehydrin transcript/protein accumulation and winter survival was found in both winter wheat and winter barley plants in the field conditions, but only prior to vernalization fulfillment.

  • wheat and barley Dehydrins under cold drought and salinity what can lea ii proteins tell us about plant stress response
    Frontiers in Plant Science, 2014
    Co-Authors: Klára Kosová, Pavel Vítámvás, Ilja Tom Prášil
    Abstract:

    Dehydrins as a group of Late embryogenesis abundant II (LEA-II) proteins represent important dehydration-inducible proteins whose accumulation is induced by developmental processes (embryo maturation) as well as by several abiotic stress factors (low temperatures, drought, salinity). In the review, an overview of studies aimed at investigation of Dehydrin accumulation patterns at transcript and protein levels as well as their possible functions in common wheat (Triticum aestivum), durum wheat (Triticum durum) and barley (Hordeum vulgare) plants exposed to various abiotic stress factors (cold, frost, drought, salinity) is provided. Possible roles of Dehydrin proteins in an acquisition and maintenance of an enhanced frost tolerance are analysed in the context of plant developmental processes (vernalization). Quantitative and qualitative differences as well as posttranslational modifications in accumulated Dehydrin proteins between barley cultivars revealing differential tolerance to drought and salinity are also discussed. Current knowledge on Dehydrin role in wheat and barley response to major dehydrative stresses is summarized and the major challenges in Dehydrin research are outlined.

  • Expression of Dehydrins in wheat and barley under different temperatures
    Plant science : an international journal of experimental plant biology, 2010
    Co-Authors: Klára Kosová, Pavel Vítámvás, Ilja Tom Prášil
    Abstract:

    The review summarizes recent knowledge on the expression of cold-inducible Dehydrins with a special attention to Wcs120 and Dhn5 genes in wheat and barley plants under different temperatures. When plants are exposed to cold, Dehydrins start accumulating both in freezing-tolerant and freezing-susceptible plants; however, their accumulation correlates with plant acquired frost tolerance (FT). During a long-term cold acclimation (CA), Dehydrin accumulation is significantly affected by Vrn1/Fr1 locus and the expression of the major vernalization gene VRN1, respectively. A different dynamics of Dehydrin transcripts and proteins during CA is also observed. Transcripts reach their maximum within the first week of CA while proteins gradually accumulate until vernalization. Vernalization is associated with a significant decrease in Dehydrin accumulation while the decrease of acquired FT is delayed. Studies carried out on plants grown at moderately cold temperatures (9-20 °C) have shown that both Dehydrin transcripts and proteins can be detected even at these temperatures and that plants with different FT levels can be distinguished according to Dehydrin accumulation without any exposure to severe cold. In conclusion, the potential use of these results in the breeding programmes aimed at the enhancement of wheat and barley FT is discussed.

Stephen K. Randall - One of the best experts on this subject based on the ideXlab platform.

  • Dehydrin expression in soybean.
    Plant physiology and biochemistry : PPB, 2013
    Co-Authors: Yuji Yamasaki, Gage Koehler, Brenda J. Blacklock, Stephen K. Randall
    Abstract:

    Soybean (Glycine max) is a relatively cold intolerant plant. In most stress tolerant plants the responsive expression of Dehydrin proteins in vegetative tissues can be a significant contributor to protection against environmental stresses. The purpose of this study was to examine the expression of Dehydrins in various organs and the cold-responses of Dehydrin genes in vegetative tissues of soybean. Examination of the soybean genome indicated the presence of genes encoding ten distinct Dehydrins. Levels of Dehydrin proteins were probed with several antibodies specific to Dehydrins or to the signature K-sequence. A single vegetatively expressed Dehydrin protein was detected and the levels were insignificantly altered in response to cold, drought, or salt stress, nor was the transcript responsive to ABA. This SK2-type, acidic Dehydrin family member (GmERD14) was purified, identified by mass spectroscopy, and shown to be in vivo phosphorylated; indicating characteristics similar to other known acidic Dehydrins. The lack of cold stress-regulated acidic Dehydrin expression may contribute to the inability of soybean to cold acclimate. While transcripts for all ten Dehydrins could be detected in various tissues, only three accumulated to significant levels in vegetative tissues (two of the KS type and one of SK2 type). One of these transcripts, a KS Dehydrin, was accumulated following cold treatments. The accumulation of the KS Dehydrin was also responsive to exogenous ABA.

  • phosphorylation regulated ion binding is a property shared by the acidic subclass Dehydrins
    Plant Cell and Environment, 2005
    Co-Authors: Muath K. Alsheikh, Jan T. Svensson, Stephen K. Randall
    Abstract:

    Dehydrins are a family of proteins that accumulate in response to abiotic stresses. Little is known about the biochemical functions of these proteins. It is known that the Arabidopsis Dehydrin, ERD14, is activated by phosphorylation to bind calcium and other ions. To begin to categorize the Arabidopsis Dehydrins into functional families, we determined whether representative members of the Dehydrin sub families share the properties of ERD14. When phosphorylated in vitro with casein kinase II; recombinant COR47, and ERD10 (and ERD14) become activated to bind calcium. ERD14 exhibited the highest calcium-binding activity followed by ERD10 and COR47. These Dehydrins, when isolated from cold-treated Arabidopsis plants were also shown to have phosphorylation-dependent, calcium-binding activity. RAB18 showed very little calcium binding activity, even though it was phosphorylated by casein kinase II. XERO2 was not phosphorylated with CKII and did not bind calcium. Competition studies suggest that other divalent cations may bind to the Dehydrins COR47, ERD10, and ERD14. Utilizing matrix-assisted laser desorption ionization - time of flight mass spectroscopy (MALDI-TOF), we determined that the poly serine region located in all three calcium-binding family members (COR47, ERD10, and ERD14) is the most likely phosphorylation site responsible for the activation of calcium binding. These results are consistent with a distinct biochemical function for the acidic subclass of Dehydrins (COR47, ERD10, and ERD14) as ion (calcium)-interacting proteins.

  • Phosphorylation regulated ion‐binding is a property shared by the acidic subclass Dehydrins
    Plant Cell and Environment, 2005
    Co-Authors: Muath K. Alsheikh, Jan T. Svensson, Stephen K. Randall
    Abstract:

    Dehydrins are a family of proteins that accumulate in response to abiotic stresses. Little is known about the biochemical functions of these proteins. It is known that the Arabidopsis Dehydrin, ERD14, is activated by phosphorylation to bind calcium and other ions. To begin to categorize the Arabidopsis Dehydrins into functional families, we determined whether representative members of the Dehydrin sub families share the properties of ERD14. When phosphorylated in vitro with casein kinase II; recombinant COR47, and ERD10 (and ERD14) become activated to bind calcium. ERD14 exhibited the highest calcium-binding activity followed by ERD10 and COR47. These Dehydrins, when isolated from cold-treated Arabidopsis plants were also shown to have phosphorylation-dependent, calcium-binding activity. RAB18 showed very little calcium binding activity, even though it was phosphorylated by casein kinase II. XERO2 was not phosphorylated with CKII and did not bind calcium. Competition studies suggest that other divalent cations may bind to the Dehydrins COR47, ERD10, and ERD14. Utilizing matrix-assisted laser desorption ionization - time of flight mass spectroscopy (MALDI-TOF), we determined that the poly serine region located in all three calcium-binding family members (COR47, ERD10, and ERD14) is the most likely phosphorylation site responsible for the activation of calcium binding. These results are consistent with a distinct biochemical function for the acidic subclass of Dehydrins (COR47, ERD10, and ERD14) as ion (calcium)-interacting proteins.

Tao Wang - One of the best experts on this subject based on the ideXlab platform.

  • mtcas31 aids symbiotic nitrogen fixation by protecting the leghemoglobin mtlb120 1 under drought stress in medicago truncatula
    Frontiers in Plant Science, 2018
    Co-Authors: Hao Feng, Jiangqi Wen, Jiangli Dong, Tao Wang
    Abstract:

    Symbiotic nitrogen fixation (SNF) in legume root nodules injects millions of tons of nitrogen into agricultural lands and provides ammonia to non-legume crops under N-deficient conditions. During plant growth and development, environmental stresses, such as drought, salt, cold, and heat stress are unavoidable. This raises an interesting question as to how the legumes cope with the environmental stress along with SNF. Under drought stress, Dehydrin proteins are accumulated, which function as protein protector and osmotic substances. In this study, we found that the Dehydrin MtCAS31 (cold-acclimation-specific 31) functions in SNF in Medicago truncatula during drought stress. We found that MtCAS31 is expressed in nodules and interacts with leghemoglobin MtLb120-1. The interaction between the two proteins protects MtLb120-1 from denaturation under thermal stress in vivo. Compared to wild type, cas31 mutants display a lower nitrogenase activity, a lower ATP/ADP ratio, higher expression of nodule senescence genes and higher accumulation of amyloplasts under dehydration conditions. The results suggested that MtCAS31 protects MtLb120-1 from the damage of drought stress. We identified a new function for Dehydrins in SNF under drought stress, which enriches the understanding of the molecular mechanism of Dehydrins.

  • Image_3_MtCAS31 Aids Symbiotic Nitrogen Fixation by Protecting the Leghemoglobin MtLb120-1 Under Drought Stress in Medicago truncatula.TIF
    2018
    Co-Authors: Hao Feng, Jiangqi Wen, Jiangli Dong, Tao Wang
    Abstract:

    Symbiotic nitrogen fixation (SNF) in legume root nodules injects millions of tons of nitrogen into agricultural lands and provides ammonia to non-legume crops under N-deficient conditions. During plant growth and development, environmental stresses, such as drought, salt, cold, and heat stress are unavoidable. This raises an interesting question as to how the legumes cope with the environmental stress along with SNF. Under drought stress, Dehydrin proteins are accumulated, which function as protein protector and osmotic substances. In this study, we found that the Dehydrin MtCAS31 (cold-acclimation-specific 31) functions in SNF in Medicago truncatula during drought stress. We found that MtCAS31 is expressed in nodules and interacts with leghemoglobin MtLb120-1. The interaction between the two proteins protects MtLb120-1 from denaturation under thermal stress in vivo. Compared to wild type, cas31 mutants display a lower nitrogenase activity, a lower ATP/ADP ratio, higher expression of nodule senescence genes and higher accumulation of amyloplasts under dehydration conditions. The results suggested that MtCAS31 protects MtLb120-1 from the damage of drought stress. We identified a new function for Dehydrins in SNF under drought stress, which enriches the understanding of the molecular mechanism of Dehydrins.

  • Table_1_MtCAS31 Aids Symbiotic Nitrogen Fixation by Protecting the Leghemoglobin MtLb120-1 Under Drought Stress in Medicago truncatula.DOCX
    2018
    Co-Authors: Hao Feng, Jiangqi Wen, Jiangli Dong, Tao Wang
    Abstract:

    Symbiotic nitrogen fixation (SNF) in legume root nodules injects millions of tons of nitrogen into agricultural lands and provides ammonia to non-legume crops under N-deficient conditions. During plant growth and development, environmental stresses, such as drought, salt, cold, and heat stress are unavoidable. This raises an interesting question as to how the legumes cope with the environmental stress along with SNF. Under drought stress, Dehydrin proteins are accumulated, which function as protein protector and osmotic substances. In this study, we found that the Dehydrin MtCAS31 (cold-acclimation-specific 31) functions in SNF in Medicago truncatula during drought stress. We found that MtCAS31 is expressed in nodules and interacts with leghemoglobin MtLb120-1. The interaction between the two proteins protects MtLb120-1 from denaturation under thermal stress in vivo. Compared to wild type, cas31 mutants display a lower nitrogenase activity, a lower ATP/ADP ratio, higher expression of nodule senescence genes and higher accumulation of amyloplasts under dehydration conditions. The results suggested that MtCAS31 protects MtLb120-1 from the damage of drought stress. We identified a new function for Dehydrins in SNF under drought stress, which enriches the understanding of the molecular mechanism of Dehydrins.

  • Data_Sheet_2_MtCAS31 Aids Symbiotic Nitrogen Fixation by Protecting the Leghemoglobin MtLb120-1 Under Drought Stress in Medicago truncatula.XLSX
    2018
    Co-Authors: Hao Feng, Jiangqi Wen, Jiangli Dong, Tao Wang
    Abstract:

    Symbiotic nitrogen fixation (SNF) in legume root nodules injects millions of tons of nitrogen into agricultural lands and provides ammonia to non-legume crops under N-deficient conditions. During plant growth and development, environmental stresses, such as drought, salt, cold, and heat stress are unavoidable. This raises an interesting question as to how the legumes cope with the environmental stress along with SNF. Under drought stress, Dehydrin proteins are accumulated, which function as protein protector and osmotic substances. In this study, we found that the Dehydrin MtCAS31 (cold-acclimation-specific 31) functions in SNF in Medicago truncatula during drought stress. We found that MtCAS31 is expressed in nodules and interacts with leghemoglobin MtLb120-1. The interaction between the two proteins protects MtLb120-1 from denaturation under thermal stress in vivo. Compared to wild type, cas31 mutants display a lower nitrogenase activity, a lower ATP/ADP ratio, higher expression of nodule senescence genes and higher accumulation of amyloplasts under dehydration conditions. The results suggested that MtCAS31 protects MtLb120-1 from the damage of drought stress. We identified a new function for Dehydrins in SNF under drought stress, which enriches the understanding of the molecular mechanism of Dehydrins.