Definition and evolution of a new symbiovar, sv. rigiduloides, among Ensifer meliloti efficiently nodulating Medicago species

At calcium and phosphate concentrations within ranges commonly encountered in soil solutions, increasing calcium concentration in flowing culture solutions markedly increased phosphate absorption by several annual legumes. Calcium increased phosphate uptake relatively more at low than at high phosphate concentration. The effect of calcium was greater for two Medicago species than for two cultivars of Trifolium subterraneum and is suggested as at least a partial explanation for the greater sensitivity of Medicago to soil acidity and its greater tolerance to soil alkalinity than Trifolium subterraneum. Pretreatment at different calcium levels had no effect on phosphate absorption, while transfer to solutions of different calcium levels caused an immediate response in phosphate uptake. These results indicate that calcium had a direct effect on phosphate absorption, rather than an indirect effect through root morphology or anatomy. It is suggested that calcium increased phosphate absorption by screening electronegative charges on the roots, thus increasing the accessibility of absorption sites to phosphate.

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Heterologous Expression of Rhizobial CelC2 Cellulase Impairs Symbiotic Signaling and Nodulation in Medicago truncatula

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-11-17-0265-r ◽

2018 ◽

Vol 31 (5) ◽

pp. 568-575 ◽

Cited By ~ 5

Author(s):

Marta Robledo ◽

Esther Menéndez ◽

Jose Ignacio Jiménez-Zurdo ◽

Raúl Rivas ◽

Encarna Velázquez ◽

...

Keyword(s):

Medicago Truncatula ◽

Cell Walls ◽

Rhizobium Leguminosarum ◽

Root Nodules ◽

Root Hairs ◽

Nod Factors ◽

Model Legume ◽

Ensifer Meliloti ◽

Early Nodulin ◽

The Impact

The infection of legume plants by rhizobia is tightly regulated to ensure accurate bacterial penetration, infection, and development of functionally efficient nitrogen-fixing root nodules. Rhizobial Nod factors (NF) have key roles in the elicitation of nodulation signaling. Infection of white clover roots also involves the tightly regulated specific breakdown of the noncrystalline apex of cell walls in growing root hairs, which is mediated by Rhizobium leguminosarum bv. trifolii cellulase CelC2. Here, we have analyzed the impact of this endoglucanase on symbiotic signaling in the model legume Medicago truncatula. Ensifer meliloti constitutively expressing celC gene exhibited delayed nodulation and elicited aberrant ineffective nodules, hampering plant growth in the absence of nitrogen. Cotreatment of roots with NF and CelC2 altered Ca2+ spiking in root hairs and induction of the early nodulin gene ENOD11. Our data suggest that CelC2 alters early signaling between partners in the rhizobia-legume interaction.

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Analysis of Genetic Distance among Nine Medicago Species by Using DNA Polymorphisms.

Ikushugaku zasshi ◽

10.1270/jsbbs1951.46.7 ◽

1996 ◽

Vol 46 (1) ◽

pp. 7-10

Author(s):

Mostafa Valizadeh ◽

Kwon Kyoo Kang ◽

Akira Kanno ◽

Toshiaki Kameya

Keyword(s):

Genetic Distance ◽

Dna Polymorphisms ◽

Medicago Species

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Differential expression of TLP, ERF1, and R2R3MYB in annual Medicago species under salinity conditions

Genetics and Molecular Research ◽

10.4238/2015.august.21.22 ◽

2015 ◽

Vol 14 (3) ◽

pp. 10152-10164 ◽

Cited By ~ 1

Author(s):

F. Gharaghani ◽

F. Rafiei ◽

N. Mirakhorli ◽

E. Ebrahimie

Keyword(s):

Differential Expression ◽

Annual Medicago ◽

Medicago Species

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Novel putative rhizobial species with different symbiovars nodulate Lotus creticus and their differential preference to distinctive soil properties

FEMS Microbiology Letters ◽

10.1093/femsle/fnaa084 ◽

2020 ◽

Vol 367 (11) ◽

Author(s):

Mokhtar Rejili ◽

Mohamed Ali BenAbderrahim ◽

Mohamed Mars ◽

Janine Darla Sherrier

Keyword(s):

Phylogenetic Analysis ◽

Soil Properties ◽

Phylogenetic Analyses ◽

Geographical Regions ◽

Ensifer Meliloti ◽

Rhizobial Species ◽

Nodc Gene

ABSTRACT Phylogenetically diverse rhizobial strains endemic to Tunisia were isolated from symbiotic nodules of Lotus creticus, growing in different arid extremophile geographical regions of Tunisia, and speciated using multiloci-phylogenetic analysis as Neorhizobium huautlense (LCK33, LCK35, LCO42 and LCO49), Ensifer numidicus (LCD22, LCD25, LCK22 and LCK25), Ensifer meliloti (LCK8, LCK9 and LCK12) and Mesorhizobium camelthorni (LCD11, LCD13, LCD31 and LCD33). In addition, phylogenetic analyses revealed eight additional strains with previously undescribed chromosomal lineages within the genera Ensifer (LCF5, LCF6 and LCF8),Rhizobium (LCF11, LCF12 and LCF14) and Mesorhizobium (LCF16 and LCF19). Analysis using the nodC gene identified five symbiovar groups, four of which were already known. The remaining group composed of two strains (LCD11 and LCD33) represented a new symbiovar of Mesorhizobium camelthorni, which we propose designating as sv. hedysari. Interestingly, we report that soil properties drive and structure the symbiosis of L. creticus and its rhizobia.

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