scholarly journals Role of cytosolic, tyrosine‐insensitive prephenate dehydrogenase in Medicago truncatula

Plant Direct ◽  
2020 ◽  
Vol 4 (5) ◽  
Author(s):  
Craig A. Schenck ◽  
Josh Westphal ◽  
Dhileepkumar Jayaraman ◽  
Kevin Garcia ◽  
Jiangqi Wen ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Prephenate Dehydrogenase

scholarly journals Role of Cytosolic, Tyrosine-Insensitive Prephenate Dehydrogenase in Medicago truncatula

2019 ◽  
Author(s):  
Craig A. Schenck ◽  
Josh Westphal ◽  
Dhileepkumar Jayaraman ◽  
Kevin Garcia ◽  
Jiangqi Wen ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
De Novo ◽  
Nitrogenase Activity ◽  
Shikimate Pathway ◽  
Growth Conditions ◽  
Precursor Feeding ◽  
Prephenate Dehydrogenase ◽  
Transposon Mutants ◽  
Arogenate Dehydrogenase

ABSTRACTL-Tyrosine (Tyr) is an aromatic amino acid synthesized de novo in plants and microbes downstream of the shikimate pathway. In plants, Tyr and a Tyr pathway intermediate, 4-hydroxyphenylpyruvate (HPP), are precursors to numerous specialized metabolites, which are crucial for plant and human health. Tyr is synthesized in the plastids by a TyrA family enzyme, arogenate dehydrogenase (ADH/TyrAa), which is feedback inhibited by Tyr. In addition to ADH enzymes, many legumes possess prephenate dehydrogenases (PDH/TyrAp), which are insensitive to Tyr and localized to the cytosol. Yet the role of PDH in legumes is currently unknown. This study isolated and characterized Tnt1-transposon mutants of MtPDH1 (pdh1) in Medicago truncatula to investigate PDH function. The pdh1 mutants lacked PDH transcript, PDH activity, and displayed little aberrant morphological phenotypes under standard growth conditions providing genetic evidence that MtPDH1 is responsible for the PDH activity detected in M. truncatula. Though plant PDH enzymes and activity have been specifically found in legumes, nodule number and nitrogenase activity of pdh1 mutants were not significantly reduced compared to wild-type (Wt) during symbiosis with nitrogen-fixing bacteria. Although Tyr levels were not significantly different between Wt and mutants under standard conditions, when carbon flux was increased by shikimate precursor feeding, mutants accumulated significantly less Tyr than Wt. These data suggest that MtPDH1 is involved in Tyr biosynthesis when the shikimate pathway is stimulated, and possibly linked to unidentified legume-specific specialized metabolism.

Insight into the role of anthocyanin biosynthesis-related genes in Medicago truncatula mutants impaired in pigmentation in leaves

2013 ◽  
Vol 70 ◽  
pp. 123-132 ◽  
Author(s):  
Giorgia Carletti ◽  
Luigi Lucini ◽  
Matteo Busconi ◽  
Adriano Marocco ◽  
Jamila Bernardi
Keyword(s):  
Medicago Truncatula ◽  
Anthocyanin Biosynthesis ◽  
Insight Into

scholarly journals The proteome of Medicago truncatula in response to ammonium and urea nutrition reveals the role of membrane proteins and enzymes of root lignification

2019 ◽  
Vol 162 ◽  
pp. 168-180 ◽  
Author(s):  
Beatriz Royo ◽  
Raquel Esteban ◽  
Javier Buezo ◽  
Enrique Santamaría ◽  
Joaquín Fernández-Irigoyen ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Medicago Truncatula

scholarly journals Expression of small GTPases in the roots and nodules of Medicago truncatula cv. Jemalong

2019 ◽  
Vol 78 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Abdul Razaque Memon ◽  
Christiane Katja Schwager ◽  
Karsten Niehaus
Keyword(s):  
Medicago Truncatula ◽  
Binding Proteins ◽  
Polymerase Chain Reaction Analysis ◽  
Small Gtpases ◽  
Infection Process ◽  
Nodule Development ◽  
Gtp Binding Proteins ◽  
Gtp Binding ◽  
Differential Expression Pattern

Abstract In this study we used Medicago truncatula, to identify and analyze the expression of small GTP-binding proteins (Arf1, Arl1, Sar1, Rabs, Rop/Rac) and their interacting partners in the infection process in the roots and nodules. A real-time polymerase chain reaction analysis was carried out and our results showed that Arf1 (AtArfB1c-like), MtSar1, AtRabA1e-like, AtRabC1-like, MsRab11-like and AtRop7-like genes were highly expressed in the nodules of rhizobium inoculated plants compared to the non-inoculated ones. On the contrary, AtRabA3 like, AtRab5c and MsRac1-like genes were highly expressed in non-infected nitrogen supplied roots of M. truncatula. Other Rab genes (AtRabA4a, AtRabA4c and AtRabG3a-like genes) were nearly equally expressed in both treatments. Interestingly, RbohB (a respiratory burst NADPH oxidase homologue) was more highly expressed in rhizobium infected than in non-infected roots and nodules. Our data show a differential expression pattern of small GTP-binding proteins in roots and nodules of the plants. This study demonstrates an important role of small GTP-binding proteins in symbiosome biogenesis and root nodule development in legumes.

scholarly journals MtBZR1 Plays an Important Role in Nodule Development in Medicago truncatula

2019 ◽  
Vol 20 (12) ◽  
pp. 2941
Author(s):  
Can Cui ◽  
Hongfeng Wang ◽  
Limei Hong ◽  
Yiteng Xu ◽  
Yang Zhao ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Normal Growth ◽  
Dry Mass ◽  
Growth Conditions ◽  
Nodule Development ◽  
Functional Study ◽  
Loss Of Function ◽  
Wild Type

Brassinosteroid (BR) is an essential hormone in plant growth and development. The BR signaling pathway was extensively studied, in which BRASSINAZOLE RESISTANT 1 (BZR1) functions as a key regulator. Here, we carried out a functional study of the homolog of BZR1 in Medicago truncatula R108, whose expression was induced in nodules upon Sinorhizobium meliloti 1021 inoculation. We identified a loss-of-function mutant mtbzr1-1 and generated 35S:MtBZR1 transgenic lines for further analysis at the genetic level. Both the mutant and the overexpression lines of MtBZR1 showed no obvious phenotypic changes under normal growth conditions. After S. meliloti 1021 inoculation, however, the shoot and root dry mass was reduced in mtbzr1-1 compared with the wild type, caused by partially impaired nodule development. The transcriptomic analysis identified 1319 differentially expressed genes in mtbzr1-1 compared with wild type, many of which are involved in nodule development and secondary metabolite biosynthesis. Our results demonstrate the role of MtBZR1 in nodule development in M. truncatula, shedding light on the potential role of BR in legume–rhizobium symbiosis.

scholarly journals Crucial role of (homo)glutathione in nitrogen fixation in Medicago truncatula nodules

2011 ◽  
Vol 192 (2) ◽  
pp. 496-506 ◽  
Author(s):  
Sarra El Msehli ◽  
Annie Lambert ◽  
Fabien Baldacci-Cresp ◽  
Julie Hopkins ◽  
Eric Boncompagni ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Medicago Truncatula ◽  
Crucial Role

Physiological and metabolomic analysis of a knockout mutant suggests a critical role of MtP5CS3 gene in osmotic stress tolerance of Medicago truncatula

Euphytica ◽  
2013 ◽  
Vol 193 (1) ◽  
pp. 101-120 ◽  
Author(s):  
Minh Luan Nguyen ◽  
Goon-Bo Kim ◽  
Sun-Hee Hyun ◽  
Seok-Young Lee ◽  
Chae-Young Lee ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Stress Tolerance ◽  
Medicago Truncatula ◽  
Critical Role ◽  
Metabolomic Analysis ◽  
Knockout Mutant ◽  
Osmotic Stress Tolerance

scholarly journals ARP2/3-Mediated Actin Nucleation Associated With Symbiosome Membrane Is Essential for the Development of Symbiosomes in Infected Cells of Medicago truncatula Root Nodules

2015 ◽  
Vol 28 (5) ◽  
pp. 605-614 ◽  
Author(s):  
Aleksandr Gavrin ◽  
Veerle Jansen ◽  
Sergey Ivanov ◽  
Ton Bisseling ◽  
Elena Fedorova
Keyword(s):  
Actin Cytoskeleton ◽  
Host Cell ◽  
Medicago Truncatula ◽  
Root Nodules ◽  
Nitrogen Fixing ◽  
Actin Networks ◽  
Cell Plasma ◽  
Membrane Compartments ◽  
Infected Cells

The nitrogen-fixing rhizobia in the symbiotic infected cells of root nodules are kept in membrane compartments derived from the host cell plasma membrane, forming what are known as symbiosomes. These are maintained as individual units, with mature symbiosomes having a specific radial position in the host cell cytoplasm. The mechanisms that adapt the host cell architecture to accommodate intracellular bacteria are not clear. The intracellular organization of any cell depends heavily on the actin cytoskeleton. Dynamic rearrangement of the actin cytoskeleton is crucial for cytoplasm organization and intracellular trafficking of vesicles and organelles. A key component of the actin cytoskeleton rearrangement is the ARP2/3 complex, which nucleates new actin filaments and forms branched actin networks. To clarify the role of the ARP2/3 complex in the development of infected cells and symbiosomes, we analyzed the pattern of actin microfilaments and the functional role of ARP3 in Medicago truncatula root nodules. In infected cells, ARP3 protein and actin were spatially associated with maturing symbiosomes. Partial ARP3 silencing causes defects in symbiosome development; in particular, ARP3 silencing disrupts the final differentiation steps in functional maturation into nitrogen-fixing units.

Deciphering the role of the alternative respiration under salt stress in Medicago truncatula

2019 ◽  
pp. 261-267
Author(s):  
Nestor F Del‐Saz ◽  
Francisco Palma ◽  
Jose Antonio Herrera‐Cervera ◽  
Miquel Ribas‐Carbo
Keyword(s):  
Salt Stress ◽  
Medicago Truncatula ◽  
Alternative Respiration
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