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.

Transcript enrichment of Nod factor-elicited early nodulin genes in purified root hair fractions of the model legume Medicago truncatula

2005 ◽  
Vol 56 (419) ◽  
pp. 2507-2513 ◽  
Author(s):  
Laurent Sauviac ◽  
Andreas Niebel ◽  
Aurélien Boisson-Dernier ◽  
David G. Barker ◽  
Fernanda de Carvalho-Niebel
Keyword(s):  
Medicago Truncatula ◽  
Root Hair ◽  
Model Legume ◽  
Nod Factor ◽  
Early Nodulin ◽  
Nodulin Genes

scholarly journals Genomics-based selection and functional characterization of triterpene glycosyltransferases from the model legume Medicago truncatula

2005 ◽  
Vol 41 (6) ◽  
pp. 875-887 ◽  
Author(s):  
Lahoucine Achnine ◽  
David V. Huhman ◽  
Mohamed A. Farag ◽  
Lloyd W. Sumner ◽  
Jack W. Blount ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Functional Characterization ◽  
Model Legume

scholarly journals The HCL gene of Medicago truncatula controls Rhizobium-induced root hair curling

Development ◽  
2001 ◽  
Vol 128 (9) ◽  
pp. 1507-1518 ◽  
Author(s):  
R. Catoira ◽  
A.C. Timmers ◽  
F. Maillet ◽  
C. Galera ◽  
R.V. Penmetsa ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Root Hair ◽  
Cortical Cell ◽  
Wild Type ◽  
Cortical Cells ◽  
Model Legume ◽  
Infection Threads ◽  
Microtubular Cytoskeleton ◽  
Hair Curling ◽  
Root Hair Curling

The symbiotic infection of the model legume Medicago truncatula by Sinorhizobium meliloti involves marked root hair curling, a stage where entrapment of the microsymbiont occurs in a chamber from which infection thread formation is initiated within the root hair. We have genetically dissected these early symbiotic interactions using both plant and rhizobial mutants and have identified a M. truncatula gene, HCL, which controls root hair curling. S. meliloti Nod factors, which are required for the infection process, induced wild-type epidermal nodulin gene expression and root hair deformation in hcl mutants, while Nod factor induction of cortical cell division foci was reduced compared to wild-type plants. Studies of the position of nuclei and of the microtubule cytoskeleton network of hcl mutants revealed that root hair, as well as cortical cells, were activated in response to S. meliloti. However, the asymmetric microtubule network that is typical of curled root hairs, did not form in the mutants, and activated cortical cells did not become polarised and did not exhibit the microtubular cytoplasmic bridges characteristic of the pre-infection threads induced by rhizobia in M. truncatula. These data suggest that hcl mutations alter the formation of signalling centres that normally provide positional information for the reorganisation of the microtubular cytoskeleton in epidermal and cortical cells.

scholarly journals In planta haploid induction by genome editing of DMP in the model legume Medicago truncatula

2021 ◽  
Author(s):  
Na Wang ◽  
Xiuzhi Xia ◽  
Teng Jiang ◽  
Lulu Li ◽  
Pengcheng Zhang ◽  
...  
Keyword(s):  
Genome Editing ◽  
Medicago Truncatula ◽  
In Planta ◽  
Haploid Induction ◽  
Model Legume

scholarly journals Genome-Wide Identification and Analyses of Drought/Salt-Responsive Cytochrome P450 Genes in Medicago truncatula

2021 ◽  
Vol 22 (18) ◽  
pp. 9957
Author(s):  
Yaying Xia ◽  
Junfeng Yang ◽  
Lin Ma ◽  
Su Yan ◽  
Yongzhen Pang
Keyword(s):  
Cytochrome P450 ◽  
Secondary Metabolism ◽  
Expression Pattern ◽  
Medicago Truncatula ◽  
Functional Characterization ◽  
Hub Genes ◽  
Model Legume ◽  
Genome Wide ◽  
Duplication Events ◽  
Growth Development

Cytochrome P450 monooxygenases (P450s) catalyze a great number of biochemical reactions and play vital roles in plant growth, development and secondary metabolism. As yet, the genome-scale investigation on P450s is still lacking in the model legume Medicago truncatula. In particular, whether and how many MtP450s are involved in drought and salt stresses for Medicago growth, development and yield remain unclear. In this study, a total of 346 MtP450 genes were identified and classified into 10 clans containing 48 families. Among them, sixty-one MtP450 genes pairs are tandem duplication events and 10 MtP450 genes are segmental duplication events. MtP450 genes within one family exhibit high conservation and specificity in intron–exon structure. Meanwhile, many Mt450 genes displayed tissue-specific expression pattern in various tissues. Specifically, the expression pattern of 204 Mt450 genes under drought/NaCl treatments were analyzed by using the weighted correlation network analysis (WGCNA). Among them, eight genes (CYP72A59v1, CYP74B4, CYP71AU56, CYP81E9, CYP71A31, CYP704G6, CYP76Y14, and CYP78A126), and six genes (CYP83D3, CYP76F70, CYP72A66, CYP76E1, CYP74C12, and CYP94A52) were found to be hub genes under drought/NaCl treatments, respectively. The expression levels of these selected hub genes could be induced, respectively, by drought/NaCl treatments, as validated by qPCR analyses, and most of these genes are involved in the secondary metabolism and fatty acid pathways. The genome-wide identification and co-expression analyses of M. truncatulaP450 superfamily genes established a gene atlas for a deep and systematic investigation of P450 genes in M. truncatula, and the selected drought-/salt-responsive genes could be utilized for further functional characterization and molecular breeding for resistance in legume crops.

scholarly journals The outward Shaker channel OsK5.2 is beneficial to the plant salt tolerance through its role in K+ translocation and its control of leaf transpiration

2021 ◽  
Author(s):  
Jing Zhou ◽  
Thanh Hao Nguyen ◽  
Doan Trung Luu ◽  
Herve Sentenac ◽  
Anne-Alienor Very
Keyword(s):  
Salt Tolerance ◽  
Crop Production ◽  
Reverse Genetics ◽  
Stomatal Closure ◽  
Xylem Sap ◽  
K Channel ◽  
Saline Treatment ◽  
Leaf Transpiration ◽  
Underlying Mechanisms ◽  
Plant Salt Tolerance

High soil salinity constitutes a major environmental constraint to crop production worldwide, and the identification of genetic determinants of plant salt tolerance is awaited by breeders. While the leaf K+ to Na+ homeostasis is considered as key parameter of plant salt tolerance, the underlying mechanisms are not fully identified. Especially, the contribution of K+ channels to this homeostasis has been scarcely examined. Here, we show, using a reverse genetics approach, that the outwardly-rectifying K+ channel OsK5.2, involved in K+ translocation to the shoot and K+ release by guard cells for stomatal closure, is a strong determinant of rice salt tolerance. Upon saline treatment, OsK5.2 function in xylem sap K+ load was maintained, and even transiently increased, in roots. OsK5.2 selectively handled K+ in roots and was not involved in xylem sap Na+ load. In shoots, OsK5.2 expression was up-regulated from the onset of the saline treatment, enabling fast reduction of stomatal aperture, decreased transpirational water flow and therefore decreased trans-plant Na+ flux and reduced leaf Na+ accumulation. Thus, the OsK5.2 functions allowed shoot K+ nutrition while minimizing arrival of Na+, and appeared highly beneficial to the leaf K+ to Na+ homeostasis, the avoidance of salt toxicity and plant growth maintaining.

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 UGT84F9 is the major flavonoid UDP-glucuronosyltransferase in Medicago truncatula

2021 ◽  
Author(s):  
Olubu A Adiji ◽  
Maite L Docampo-Palacios ◽  
Anislay Alvarez-Hernandez ◽  
Giulio M Pasinetti ◽  
Xiaoqiang Wang ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Phase Ii ◽  
Loss Of Function ◽  
In Planta ◽  
Model Legume ◽  
Flavonoid Compounds ◽  
Wide Range ◽  
Udp Glucuronosyltransferase ◽  
Phase Ii Metabolites

Abstract Mammalian phase II metabolism of dietary plant flavonoid compounds generally involves substitution with glucuronic acid. In contrast, flavonoids mainly exist as glucose conjugates in plants, and few plant UDP-glucuronosyltransferase enzymes have been identified to date. In the model legume Medicago truncatula, the major flavonoid compounds in the aerial parts of the plant are glucuronides of the flavones apigenin and luteolin. Here we show that the M. truncatula glycosyltransferase UGT84F9 is a bi-functional glucosyl/glucuronosyl transferase in vitro, with activity against a wide range of flavonoid acceptor molecules including flavones. However, analysis of metabolite profiles in leaves and roots of M. truncatula ugt84f9 loss of function mutants revealed that the enzyme is essential for formation of flavonoid glucuronides, but not most flavonoid glucosides, in planta. We discuss the use of plant UGATs for the semi-synthesis of flavonoid phase II metabolites for clinical studies.

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