scholarly journals 14-3-3 Proteins and Other Candidates form Protein-Protein Interactions with the Cytosolic C-terminal End of SOS1 Affecting Its Transport Activity

2020 ◽  
Vol 21 (9) ◽  
pp. 3334 ◽  
Author(s):  
Kerstin Duscha ◽  
Cristina Martins Rodrigues ◽  
Maria Müller ◽  
Ruth Wartenberg ◽  
Larry Fliegel ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Protein Interactions ◽  
Soluble Sugar ◽  
Underlying Mechanism ◽  
Transport Activity ◽  
Wild Type ◽  
Protein Protein Interactions ◽  
Cell Extracts ◽  
Plant Salt Tolerance

The plasma membrane transporter SOS1 (SALT-OVERLY SENSITIVE1) is vital for plant survival under salt stress. SOS1 activity is tightly regulated, but little is known about the underlying mechanism. SOS1 contains a cytosolic, autoinhibitory C-terminal tail (abbreviated as SOS1 C-term), which is targeted by the protein kinase SOS2 to trigger its transport activity. Here, to identify additional binding proteins that regulate SOS1 activity, we synthesized the SOS1 C-term domain and used it as bait to probe Arabidopsis thaliana cell extracts. Several 14-3-3 proteins, which function in plant salt tolerance, specifically bound to and interacted with the SOS1 C-term. Compared to wild-type plants, when exposed to salt stress, Arabidopsis plants overexpressing SOS1 C-term showed improved salt tolerance, significantly reduced Na+ accumulation in leaves, reduced induction of the salt-responsive gene WRKY25, decreased soluble sugar, starch, and proline levels, less impaired inflorescence formation and increased biomass. It appears that overexpressing SOS1 C-term leads to the sequestration of inhibitory 14-3-3 proteins, allowing SOS1 to be more readily activated and leading to increased salt tolerance. We propose that the SOS1 C-term binds to previously unknown proteins such as 14-3-3 isoforms, thereby regulating salt tolerance. This finding uncovers another regulatory layer of the plant salt tolerance program.

scholarly journals PLATZ2 negatively regulates salt tolerance in Arabidopsis seedlings by directly suppressing the expression of the CBL4/SOS3 and CBL10/SCaBP8 genes

2020 ◽  
Vol 71 (18) ◽  
pp. 5589-5602
Author(s):  
Shasha Liu ◽  
Rui Yang ◽  
Miao Liu ◽  
Shizhong Zhang ◽  
Kang Yan ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Transgenic Plants ◽  
Loss Of Function ◽  
Wild Type ◽  
Salt Stress Response ◽  
In The Wild ◽  
Plant Salt Tolerance

Abstract Although the salt overly sensitive (SOS) pathway plays essential roles in conferring salt tolerance in Arabidopsis thaliana, the regulatory mechanism underlying SOS gene expression remains largely unclear. In this study, AtPLATZ2 was found to function as a direct transcriptional suppressor of CBL4/SOS3 and CBL10/SCaBP8 in the Arabidopsis salt stress response. Compared with wild-type plants, transgenic plants constitutively overexpressing AtPLATZ2 exhibited increased sensitivity to salt stress. Loss of function of PLATZ2 had no observed salt stress phenotype in Arabidopsis, while the double mutant of PLATZ2 and PLATZ7 led to weaker salt stress tolerance than wild-type plants. Overexpression of AtPLATZ2 in transgenic plants decreased the expression of CBL4/SOS3 and CBL10/SCaBP8 under both normal and saline conditions. AtPLATZ2 directly bound to A/T-rich sequences in the CBL4/SOS3 and CBL10/SCaBP8 promoters in vitro and in vivo, and inhibited CBL4/SOS3 promoter activity in the plant leaves. The salt sensitivity of #11 plants constitutively overexpressing AtPLATZ2 was restored by the overexpression of CBL4/SOS3 and CBL10/SCaBP8. Salt stress-induced Na+ accumulation in both the shoots and roots was more exaggerated in AtPLATZ2-overexpressing plants than in the wild type. The salt stress-induced Na+ accumulation in #11 seedlings was also rescued by the overexpression of CBL4/SOS3 and CBL10/SCaBP8. Furthermore, the transcription of AtPLATZ2 was induced in response to salt stress. Collectively, these results suggest that AtPLATZ2 suppresses plant salt tolerance by directly inhibiting CBL4/SOS3 and CBL10/SCaBP8, and functions redundantly with PLATZ7.

Improvement of Torenia fournieri salinity tolerance by expression of Arabidopsis AtNHX5

2008 ◽  
Vol 35 (3) ◽  
pp. 185 ◽  
Author(s):  
Le-Yi Shi ◽  
Hong-Qing Li ◽  
Xiao-Ping Pan ◽  
Guo-Jiang Wu ◽  
Mei-Ru Li
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Potential Role ◽  
Ion Homeostasis ◽  
Leaf Explants ◽  
Wild Type ◽  
Torenia Fournieri ◽  
Regenerated Plants ◽  
Plant Salt Tolerance

In this paper, transgenic torenia plants expressing the AtNHX5 gene from Arabidopsis in sense and antisense orientations were produced to examine the potential role of AtNHX5 in plant salt tolerance and development. We found that torenia plants overexpressing AtNHX5 showed markedly enhanced tolerance to salt stress compared with both wild-type and antisense AtNHX5 transgenic plants upon salt stress. Measurements of ion levels indicated that Na+ and K+ contents were all higher in AtNHX5 overexpressing shoots than in those of both wild-type and antisense AtNHX5 shoots treated with 50 mm NaCl. This indicated that overexpression of AtNHX5 could improve the salt tolerance of transgenic torenia via accumulation of both Na+ and K+ in shoots, in which overall ion homeostasis and osmotic adjustment was changed to sustain the increase in shoot salt tolerance. Further, we found that overexpression of AtNHX5 in torenia significantly improved the shoot regeneration frequency in leaf explants and increased the plantlet survival rate when transferring the regenerated plants to soil. In addition, the AtNHX5 expressing plants produced flowers earlier than both wild-type and the antisense AtNHX5 plants. Taken together, the results indicated that AtNHX5 functions not only in plant salt tolerance but also in plant growth and development.

scholarly journals Salt acclimation induced salt tolerance in wild-type and abscisic acid-deficient mutant barley

2019 ◽  
Vol 65 (No. 10) ◽  
pp. 516-521 ◽  
Author(s):  
Zhiyu Zuo ◽  
Junhong Guo ◽  
Caiyun Xin ◽  
Shengqun Liu ◽  
Hanping Mao ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Spring Barley ◽  
Soluble Sugar ◽  
Deficient Mutant ◽  
Wild Type ◽  
Hordeum Vulgare L ◽  
Ps Ii ◽  
Salt Acclimation

Salt acclimation is a process to enhance salt tolerance in plants. The salt acclimation induced salt tolerance was investigated in a spring barley (Hordeum vulgare L.) cv. Steptoe (wild type, WT) and its abscisic acid (ABA)-deficient mutant Az34. Endogenesis ABA concentration in leaf was significantly increased by salt stress in WT, while it was not affected in Az34. Under salt stress, the salt acclimated Az34 plants had 14.8% lower total soluble sugar concentration and 93.7% higher sodium (Na) concentration in leaf, compared with salt acclimated WT plants. The acclimated plants had significantly higher leaf water potential and osmotic potential than non-acclimated plants in both WT and Az34 under salt stress. The salt acclimation enhanced the net photosynthetic rate (by 22.9% and 12.3%) and the maximum quantum yield of PS II (22.7% and 22.0%) in WT and Az34 under salt stress. However, the stomatal conductance in salt acclimated Az34 plants was 28.9% lower than WT under salt stress. Besides, the guard cell pair width was significantly higher in salt acclimated Az34 plants than that in WT plants. The results indicated that the salt acclimated WT plants showed a higher salt tolerance than Az34 plants, suggesting that ABA deficiency has a negative effect on the salt acclimation induced salt tolerance in barley.

Leucine periodicity of U2 small nuclear ribonucleoprotein particle (snRNP) A' protein is implicated in snRNP assembly via protein-protein interactions

1991 ◽  
Vol 11 (3) ◽  
pp. 1578-1589
Author(s):  
L D Fresco ◽  
D S Harper ◽  
J D Keene
Keyword(s):  
Protein Interactions ◽  
Leucine Zipper ◽  
Tandem Repeats ◽  
Mutational Analysis ◽  
Particle Density ◽  
Protein Protein Interactions ◽  
Small Nuclear Ribonucleoprotein ◽  
Cell Extracts ◽  
Associated Proteins ◽  
Nuclear Ribonucleoprotein

Recombinant A' protein could be reconstituted into U2 small nuclear ribonucleoprotein particles (snRNPs) upon addition to HeLa cell extracts as determined by coimmunoprecipitation and particle density; however, direct binding to U2 RNA could not be demonstrated except in the presence of the U2 snRNP B" protein. Mutational analysis indicated that a central core region of A' was required for particle reconstitution. This region consists of five tandem repeats of approximately 24 amino acids each that exhibit a periodicity of leucine and asparagine residues that is distinct from the leucine zipper. Similar leucine-rich (Leu-Leu motif) repeats are characteristic of a diverse array of soluble and membrane-associated proteins from yeasts to humans but have not been reported previously to reside in nuclear proteins. Several of these proteins, including Toll, chaoptin, RNase/angiogenin inhibitors, lutropin-choriogonadotropin receptor, carboxypeptidase N, adenylyl cyclase, CD14, and human immunodeficiency virus type 1 Rev, may be involved in protein-protein interactions. Our findings suggest that in cell extracts the Leu-Leu motif of A' is required for reconstitution with U2 snRNPs and perhaps with other components involved in splicing through protein-protein interactions.

Methyl jasmonate improves tolerance to high salt stress in the recretohalophyte Limonium bicolor

2019 ◽  
Vol 46 (1) ◽  
pp. 82 ◽  
Author(s):  
Fang Yuan ◽  
Xue Liang ◽  
Ying Li ◽  
Shanshan Yin ◽  
Baoshan Wang
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Methyl Jasmonate ◽  
Salt Gland ◽  
Underlying Mechanism ◽  
Photosynthetic Parameters ◽  
Salt Glands ◽  
Plasma Membrane Permeability ◽  
Limonium Bicolor ◽  
Relative Electrical Conductivity

Limonium bicolor is a typical recretohalophyte with salt glands in the epidermis, which shows maximal growth at moderate salt concentrations (100mM NaCl) but reduced growth in the presence of excess salt (more than 200mM). Jasmonic acid (JA) alleviates the reduced growth of L. bicolor under salt stress; however, the underlying mechanism is unknown. In this study we investigated the effects of exogenous methyl jasmonate (MeJA) application on L. bicolor growth at high NaCl concentrations. We found that treatment with 300mM NaCl led to dramatic inhibition of seedling growth that was significantly alleviated by the application of 0.03mM MeJA, resulting in a biomass close to that of plants not subjected to salt stress. To determine the parameters that correlate with MeJA-induced salt tolerance (assessed as the biomass production in saline and control conditions), we measured 14 physiological parameters relating to ion contents, plasma membrane permeability, photosynthetic parameters, salt gland density, and salt secretion. We identified a correlation between individual indicators and salt tolerance: the most positively correlated indicator was net photosynthetic rate, and the most negatively correlated one was relative electrical conductivity. These findings provide insights into a possible mechanism underlying MeJA-mediated salt stress alleviation.

A Functional Alternative Oxidase Modulates Plant Salt Tolerance in Physcomitrella patens

2019 ◽  
Vol 60 (8) ◽  
pp. 1829-1841 ◽  
Author(s):  
Guochun Wu ◽  
Sha Li ◽  
Xiaochuan Li ◽  
Yunhong Liu ◽  
Shuangshuang Zhao ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Alternative Oxidase ◽  
Physcomitrella Patens ◽  
Redox Homeostasis ◽  
Respiratory Pathway ◽  
Functional Link ◽  
Salt Stress Condition ◽  
Plant Salt Tolerance

Abstract Alternative oxidase (AOX) has been reported to be involved in mitochondrial function and redox homeostasis, thus playing an essential role in plant growth as well as stress responses. However, its biological functions in nonseed plants have not been well characterized. Here, we report that AOX participates in plant salt tolerance regulation in moss Physcomitrella patens (P. patens). AOX is highly conserved and localizes to mitochondria in P. patens. We observed that PpAOX rescued the impaired cyanide (CN)-resistant alternative (Alt) respiratory pathway in Arabidopsis thaliana (Arabidopsis) aox1a mutant. PpAOX transcription and Alt respiration were induced upon salt stress in P. patens. Using homologous recombination, we generated PpAOX-overexpressing lines (PpAOX OX). PpAOX OX plants exhibited higher Alt respiration and lower total reactive oxygen species accumulation under salt stress condition. Strikingly, we observed that PpAOX OX plants displayed decreased salt tolerance. Overexpression of PpAOX disturbed redox homeostasis in chloroplasts. Meanwhile, chloroplast structure was adversely affected in PpAOX OX plants in contrast to wild-type (WT) P. patens. We found that photosynthetic activity in PpAOX OX plants was also lower compared with that in WT. Together, our work revealed that AOX participates in plant salt tolerance in P. patens and there is a functional link between mitochondria and chloroplast under challenging conditions.

scholarly journals PF16 encodes a protein with armadillo repeats and localizes to a single microtubule of the central apparatus in Chlamydomonas flagella.

1996 ◽  
Vol 132 (3) ◽  
pp. 359-370 ◽  
Author(s):  
E F Smith ◽  
P A Lefebvre
Keyword(s):  
Protein Interactions ◽  
Insertional Mutagenesis ◽  
Flagellar Motility ◽  
Wild Type ◽  
Protein Protein Interactions ◽  
Cellular Functions ◽  
Central Pair ◽  
Central Apparatus ◽  
Immunofluorescence Labeling ◽  
Armadillo Repeats

Several studies have indicated that the central pair of microtubules and their associated structures play a significant role in regulating flagellar motility. To begin a molecular analysis of these components we have generated central apparatus-defective mutants in Chlamydomonas reinhardtii using insertional mutagenesis. One paralyzed mutant recovered in our screen, D2, is an allele of a previously identified mutant, pf16. Mutant cells have paralyzed flagella, and the C1 microtubule of the central apparatus is missing in isolated axonemes. We have cloned the wild-type PF16 gene and confirmed its identity by rescuing pf16 mutants upon transformation. The rescued pf16 cells were wild-type in motility and in axonemal ultrastructure. A full-length cDNA clone for PF16 was obtained and sequenced. Database searches using the predicted 566 amino acid sequence of PF16 indicate that the protein contains eight contiguous armadillo repeats. A number of proteins with diverse cellular functions also contain armadillo repeats including pendulin, Rch1, importin, SRP-1, and armadillo. An antibody was raised against a fusion protein expressed from the cloned cDNA. Immunofluorescence labeling of wild-type flagella indicates that the PF16 protein is localized along the length of the flagella while immunogold labeling further localizes the PF16 protein to a single microtubule of the central pair. Based on the localization results and the presence of the armadillo repeats in this protein, we suggest that the PF16 gene product is involved in protein-protein interactions important for C1 central microtubule stability and flagellar motility.

scholarly journals Overexpression of a Novel ROP Gene from the Banana (MaROP5g) Confers Increased Salt Stress Tolerance

2018 ◽  
Vol 19 (10) ◽  
pp. 3108 ◽  
Author(s):  
Hongxia Miao ◽  
Peiguang Sun ◽  
Juhua Liu ◽  
Jingyi Wang ◽  
Biyu Xu ◽  
...  
Keyword(s):  
Salt Stress ◽  
Abiotic Stress ◽  
Salt Tolerance ◽  
Stress Tolerance ◽  
Abiotic Stress Tolerance ◽  
Survival Rates ◽  
Wild Type ◽  
Ion Distribution ◽  
Membrane Injury ◽  
Primary Roots

Rho-like GTPases from plants (ROPs) are plant-specific molecular switches that are crucial for plant survival when subjected to abiotic stress. We identified and characterized 17 novel ROP proteins from Musa acuminata (MaROPs) using genomic techniques. The identified MaROPs fell into three of the four previously described ROP groups (Groups II–IV), with MaROPs in each group having similar genetic structures and conserved motifs. Our transcriptomic analysis showed that the two banana genotypes tested, Fen Jiao and BaXi Jiao, had similar responses to abiotic stress: Six genes (MaROP-3b, -5a, -5c, -5f, -5g, and -6) were highly expressed in response to cold, salt, and drought stress conditions in both genotypes. Of these, MaROP5g was most highly expressed in response to salt stress. Co-localization experiments showed that the MaROP5g protein was localized at the plasma membrane. When subjected to salt stress, transgenic Arabidopsis thaliana overexpressing MaROP5g had longer primary roots and increased survival rates compared to wild-type A. thaliana. The increased salt tolerance conferred by MaROP5g might be related to reduced membrane injury and the increased cytosolic K+/Na+ ratio and Ca2+ concentration in the transgenic plants as compared to wild-type. The increased expression of salt overly sensitive (SOS)-pathway genes and calcium-signaling pathway genes in MaROP5g-overexpressing A. thaliana reflected the enhanced tolerance to salt stress by the transgenic lines in comparison to wild-type. Collectively, our results suggested that abiotic stress tolerance in banana plants might be regulated by multiple MaROPs, and that MaROP5g might enhance salt tolerance by increasing root length, improving membrane injury and ion distribution.

scholarly journals Overexpression of Tamarix hispida ThTrx5 Confers Salt Tolerance to Arabidopsis by Activating Stress Response Signals

2020 ◽  
Vol 21 (3) ◽  
pp. 1165
Author(s):  
Jiayu Luan ◽  
Jingxiang Dong ◽  
Xin Song ◽  
Jing Jiang ◽  
Huiyu Li
Keyword(s):  
Salt Stress ◽  
Stress Response ◽  
Salt Tolerance ◽  
Germination Rate ◽  
Nacl Stress ◽  
Tamarix Hispida ◽  
Resistant Varieties ◽  
Transcriptome Comparison ◽  
Plant Salt Tolerance ◽  
Cellular Water

Salt stress inhibits normal plant growth and development by disrupting cellular water absorption and metabolism. Therefore, understanding plant salt tolerance mechanisms should provide a theoretical basis for developing salt-resistant varieties. Here, we cloned ThTrx5 from Tamarix hispida, a salt-resistant woody shrub, and generated ThTrx5-overexpressing transgenic Arabidopsis thaliana lines. Under NaCl stress, the germination rate of overexpressing ThTrx5 lines was significantly increased relative to that of the nontransgenic line; under salt stress, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione levels and root length and fresh weight values of transgenic ThTrx5 plants were significantly greater than corresponding values for wild-type plants. Moreover, with regard to the transcriptome, comparison of differential gene expression of transgenic versus nontransgenic lines at 0 h and 3 h of salt stress exposure revealed 500 and 194 differentially expressed genes (DEGs), respectively, that were mainly functionally linked to catalytic activity and binding process. Pull-down experiments showed that ThTrx bound 2-Cys peroxiredoxin BAS1-like protein that influences stress response-associated redox, hormone signal transduction, and transcription factor functions. Therefore, this work provides important insights into ThTrx5 mechanisms that promote salt tolerance in plants.

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