scholarly journals Functional characterization and physiological roles of the single Shaker outward K + channel in Medicago truncatula

2020 ◽  
Vol 102 (6) ◽  
pp. 1249-1265 ◽  
Author(s):  
Alice Drain ◽  
Julien Thouin ◽  
Limin Wang ◽  
Martin Boeglin ◽  
Nicolas Pauly ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Functional Characterization ◽  
K Channel

scholarly journals Medicago truncatula possesses a single Shaker outward K+ channel: functional characterization and roles in planta

2019 ◽  
Author(s):  
Alice Drain ◽  
Julien Thouin ◽  
Limin Wang ◽  
Nicolas Pauly ◽  
Manuel Nieves-Cordones ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Root Hair ◽  
Stomatal Closure ◽  
Functional Characterization ◽  
Xylem Sap ◽  
K Channel ◽  
In Planta ◽  
Model Legume ◽  
Rhizobial Symbiosis ◽  
Electrical Signaling

SUMMARYThe model legume Medicago truncatula possesses a single outward Shaker K+ channel, while Arabidopsis thaliana possesses two channels of this type, named SKOR and GORK, the former having been shown to play a major role in K+ secretion into the xylem sap in the root vasculature and the latter to mediate the efflux of K+ across the guard cell membrane upon stomatal closure. Here we show that the expression pattern of the single M. truncatula outward Shaker channel, which has been named MtGORK, includes the root vasculature, guard cells and root hairs. As shown by patch-clamp experiments on root hair protoplasts, besides the Shaker-type slowly-activating outwardly-rectifying K+ conductance encoded by MtGORK, a second K+-permeable conductance, displaying fast activation and weak rectification, can be expressed by M. truncatula. A KO mutation resulting in absence of MtGORK activity is shown to weakly reduce K+ translocation to shoots, and only in plants engaged in rhizobial symbiosis, but to strongly affect the control of stomatal aperture and transpitational water loss. In legumes, the early electrical signaling pathway triggered by Nod Factor perception is known to comprise a short transient depolarization of the root hair plasma membrane. In absence of MtGORK functional expression, while the rate of the membrane repolarization is shown to be decreased by about 3 times, this defect is without any consequence on infection thread development and nodule production, indicating that the plant capacity to engage rhizobial symbiosis does not require integrity of the early electrical signaling events.

Dynamic regulation of the voltage-gated Kv2.1 potassium channel by multisite phosphorylation

2007 ◽  
Vol 35 (5) ◽  
pp. 1064-1068 ◽  
Author(s):  
D.P. Mohapatra ◽  
K.-S. Park ◽  
J.S. Trimmer
Keyword(s):  
Neuronal Excitability ◽  
Critical Role ◽  
Functional Characterization ◽  
K Channel ◽  
Delayed Rectifier ◽  
Dynamic Regulation ◽  
Voltage Gated ◽  
Voltage Dependent ◽  
Specific Regulation

Voltage-gated K+ channels are key regulators of neuronal excitability. The Kv2.1 voltage-gated K+ channel is the major delayed rectifier K+ channel expressed in most central neurons, where it exists as a highly phosphorylated protein. Kv2.1 plays a critical role in homoeostatic regulation of intrinsic neuronal excitability through its activity- and calcineurin-dependent dephosphorylation. Here, we review studies leading to the identification and functional characterization of in vivo Kv2.1 phosphorylation sites, a subset of which contribute to graded modulation of voltage-dependent gating. These findings show that distinct developmental-, cell- and state-specific regulation of phosphorylation at specific sites confers a diversity of functions on Kv2.1 that is critical to its role as a regulator of intrinsic neuronal excitability.

Cloning and functional characterization of epidermis-specific promoter MtML1 from Medicago truncatula

2019 ◽  
Vol 300 ◽  
pp. 32-39 ◽  
Author(s):  
Li Gao ◽  
Ye Tian ◽  
Meng-Ci Chen ◽  
Li Wei ◽  
Tian-Ge Gao ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Functional Characterization

Functional Characterization of a Cloned Human Intermediate-Conductance Ca2+-Activated K+ Channel

1999 ◽  
Vol 868 (1 MOLECULAR AND) ◽  
pp. 423-426 ◽  
Author(s):  
TINO DYHRING JORGENSEN ◽  
BO SKAANING JENSEN ◽  
DORTE STROBAEK ◽  
PALLE CHRISTOPHERSEN ◽  
SOREN-PETER OLESEN ◽  
...  
Keyword(s):  
Functional Characterization ◽  
K Channel

scholarly journals Functional characterization of RK5, a voltage-gated K+channel cloned from the rat cardiovascular system

FEBS Letters ◽  
1991 ◽  
Vol 295 (1-3) ◽  
pp. 211-213 ◽  
Author(s):  
T.Ann Blair ◽  
Steven L. Roberds ◽  
Michael M. Tamkun ◽  
Robert P. Hartshorne
Keyword(s):  
Cardiovascular System ◽  
Functional Characterization ◽  
K Channel ◽  
Voltage Gated

Isolation and functional characterization of salt-stress induced RCI2-like genes from Medicago sativa and Medicago truncatula

2015 ◽  
Vol 128 (4) ◽  
pp. 697-707 ◽  
Author(s):  
Ruicai Long ◽  
Fan Zhang ◽  
Zhenyi Li ◽  
Mingna Li ◽  
Lili Cong ◽  
...  
Keyword(s):  
Salt Stress ◽  
Medicago Sativa ◽  
Medicago Truncatula ◽  
Functional Characterization

scholarly journals Genome-wide identification and expression profiling of glutathione S-transferase family under multiple abiotic and biotic stresses in Medicago truncatula L.

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247170
Author(s):  
Md. Soyib Hasan ◽  
Vishal Singh ◽  
Shiful Islam ◽  
Md. Sifatul Islam ◽  
Raju Ahsan ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Expression Profiling ◽  
Developmental Stages ◽  
Functional Characterization ◽  
Drought Treatment ◽  
Specific Expression ◽  
Abiotic And Biotic Stresses ◽  
Biotic Stresses ◽  
Genome Wide

Glutathione transferases (GSTs) constitute an ancient, ubiquitous, multi-functional antioxidant enzyme superfamily that has great importance on cellular detoxification against abiotic and biotic stresses as well as plant development and growth. The present study aimed to a comprehensive genome-wide identification and functional characterization of GST family in one of the economically important legume plants—Medicago truncatula. Here, we have identified a total of ninety-two putative MtGST genes that code for 120 proteins. All these members were classified into twelve classes based on their phylogenetic relationship and the presence of structural conserved domain/motif. Among them, 7 MtGST gene pairs were identified to have segmental duplication. Expression profiling of MtGST transcripts revealed their high level of organ/tissue-specific expression in most of the developmental stages and anatomical tissues. The transcripts of MtGSTU5, MtGSTU8, MtGSTU17, MtGSTU46, and MtGSTU47 showed significant up-regulation in response to various abiotic and biotic stresses. Moreover, transcripts of MtGSTU8, MtGSTU14, MtGSTU28, MtGSTU30, MtGSTU34, MtGSTU46 and MtGSTF8 were found to be highly upregulated in response to drought treatment for 24h and 48h. Among the highly stress-responsive MtGST members, MtGSTU17 showed strong affinity towards its conventional substrates reduced glutathione (GSH) and 1‐chloro‐2,4‐dinitrobenzene (CDNB) with the lowest binding energy of—5.7 kcal/mol and -6.5 kcal/mol, respectively. Furthermore, the substrate-binding site residues of MtGSTU17 were found to be highly conserved. These findings will facilitate the further functional and evolutionary characterization of GST genes in Medicago.

scholarly journals Genome-Wide Identification and Expression Analysis of Metal Tolerance Protein Gene Family in Medicago truncatula Under a Broad Range of Heavy Metal Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Ahmed H. El-Sappah ◽  
Rania G. Elbaiomy ◽  
Ahmed S. Elrys ◽  
Yu Wang ◽  
Yumin Zhu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Gene Ontology ◽  
Gene Family ◽  
Medicago Truncatula ◽  
Metal Ion ◽  
Metal Tolerance ◽  
Functional Characterization ◽  
Heavy Metal Stress ◽  
Metal Stress ◽  
Gene Similarity

Metal tolerance proteins (MTPs) encompass plant membrane divalent cation transporters to specifically participate in heavy metal stress resistance and mineral acquisition. However, the molecular behaviors and biological functions of this family in Medicago truncatula are scarcely known. A total of 12 potential MTP candidate genes in the M. truncatula genome were successfully identified and analyzed for a phylogenetic relationship, chromosomal distributions, gene structures, docking analysis, gene ontology, and previous gene expression. M. truncatula MTPs (MtMTPs) were further classified into three major cation diffusion facilitator (CDFs) groups: Mn-CDFs, Zn-CDFs, and Fe/Zn-CDFs. The structural analysis of MtMTPs displayed high gene similarity within the same group where all of them have cation_efflux domain or ZT_dimer. Cis-acting element analysis suggested that various abiotic stresses and phytohormones could induce the most MtMTP gene transcripts. Among all MTPs, PF16916 is the specific domain, whereas GLY, ILE, LEU, MET, ALA, SER, THR, VAL, ASN, and PHE amino acids were predicted to be the binding residues in the ligand-binding site of all these proteins. RNA-seq and gene ontology analysis revealed the significant role of MTP genes in the growth and development of M. truncatula. MtMTP genes displayed differential responses in plant leaves, stems, and roots under five divalent heavy metals (Cd2+, Co2+, Mn2+, Zn2+, and Fe2+). Ten, seven, and nine MtMTPs responded to at least one metal ion treatment in the leaves, stems, and roots, respectively. Additionally, MtMTP1.1, MtMTP1.2, and MtMTP4 exhibited the highest expression responses in most heavy metal treatments. Our results presented a standpoint on the evolution of MTPs in M. truncatula. Overall, our study provides a novel insight into the evolution of the MTP gene family in M. truncatula and paves the way for additional functional characterization of this gene family.

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