Molecular studies of the Medicago truncatula MtAnn3 gene involved in root hair deformation

Structural and cell developmental studies of root hair deformation in Alnus rubra Bong. (Betulaceae) were carried out following inoculation with the soil pseudomonad Pseudomonas cepacia 85, alone or in concert with Frankia, and using axenically grown seedlings. Deformational changes can be observed in elongating root hairs within 2 h of inoculation with P. cepacia 85. These growing root hairs become branched or multilobed and highly modified from the single-tip growth of axenic root hairs. The cell walls of deformed hairs are histologically distinctive when stained with the fluorochrome acridine orange. Filtrate studies using P. cepacia 85 suggest that the deforming substance is not a low molecular weight compound. Root hair deformation and the associated wall histology are host specific in that Betula root hairs show none of these responses when grown and inoculated in the experimental conditions described. The bacterially induced changes in root hair cell walls during deformation may create a chemically and physically modified substrate for Frankia penetration, and the deformation itself may serve to entrap and enclose the filamentous organism, allowing wall dissolution and entry. Thus these events represent a complex host response as a precondition to successful nodulation.

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Adhesiveness and root hair deformation capacity of Azospirillum strains for wheat seedlings

Soil Biology and Biochemistry ◽

10.1016/0038-0717(94)90275-5 ◽

1994 ◽

Vol 26 (6) ◽

pp. 791-797 ◽

Cited By ~ 12

Author(s):

Marcela Zamudio ◽

Fernando Bastarrachea

Keyword(s):

Root Hair ◽

Deformation Capacity ◽

Wheat Seedlings ◽

Root Hair Deformation

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Early transcriptomic response of Alnus glutinosa to Frankia alni symbiont, an upregulated nsLTP (non-specific Lipid Transfer Protein) is implicated in early and late stages of symbiosis

10.1101/2021.10.29.465983 ◽

2021 ◽

Author(s):

Melanie Gasser ◽

Nicole Alloisio ◽

Pascale Fournier ◽

Severine Balmand ◽

Ons Kharrat ◽

...

Keyword(s):

Root Hair ◽

Lipid Transfer Protein ◽

Alnus Glutinosa ◽

Lipid Transfer ◽

Transcriptomic Response ◽

Transfer Protein ◽

Root Hair Deformation ◽

Frankia Alni ◽

Late Stages ◽

Specific Lipid

The response of Alnus glutinosa to Frankia alni is complex with several sequential physiological modifications that include calcium spiking, root hair deformation, penetration, induction of primordium, formation and growth of nodule. A transcriptomic study of seedlings in hydroponics after early contact (2.5 days) with Frankia alni, either with a culture supernatant or with living cells separated from the roots by a dialysis membrane, permitted to identify plant genes which expression level was modified upon early contact with Frankia. Forty-two genes were significantly up-regulated in both experiments, most of them encoding biological processes such as oxidative stress or response to stimuli. Among them, the most upregulated gene was a non-specific lipid transfer protein encoding gene with a fold change of 141. This nsLTP was found to increase Frankia nitrogen fixation at sub-lethal concentration. Interestingly, it was immunolocalized to a region of the deformed root hair at an early infection stage and later in nodules, it was localized around bacterial vesicles suggesting a role in early and late stages of symbiosis.

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Nod Factor-Induced Expression of Leghemoglobin to Study the Mechanism of NH4NO3 Inhibition on Root Hair Deformation

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.1997.10.2.215 ◽

1997 ◽

Vol 10 (2) ◽

pp. 215-220 ◽

Cited By ~ 52

Author(s):

Renze Heidstra ◽

Gerd Nilsen ◽

Francisco Martinez-Abarca ◽

Ab van Kammen ◽

Ton Bisseling

Keyword(s):

Gene Expression ◽

Root Hair ◽

Rhizobium Leguminosarum ◽

Cortical Cell ◽

Brefeldin A ◽

Marker Genes ◽

Nodule Formation ◽

Cdna Clones ◽

Nod Factor ◽

Root Hair Deformation

Nod factors secreted by Rhizobium leguminosarum bv. viciae induce root hair deformation, the formation of nodule primordia, and the expression of early nodulin genes in Vicia sativa (vetch). Root hair deformation is induced within 3 h in a small, susceptible zone (±2 mm) of the root. NH4NO3, known to be a potent blocker of nodule formation, inhibits root hair deformation, initial cortical cell divisions, and infection thread formation. To test whether NH4NO3 affects the formation of a component of the Nod factor perception-transduction system, we studied Nod factor-induced gene expression. The differential display technique was used to search for marker genes, which are induced within 1 to 3 h after Nod factor application. Surprisingly, one of the isolated cDNA clones was identified as a leghemoglobin gene (VsLb1), which is induced in vetch roots within 1 h after Nod factor application. By using the drug brefeldin A, it was then shown that VsLb1 activation does not require root hair deformation. The pVsLb1 clone was used as a marker to show that in vetch plants grown in the presence of NH4NO3 Nod factor perception and transduction leading to gene expression are unaffected.

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Development of Ectopic Roots from Abortive Nodule Primordia

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2004.17.10.1043 ◽

2004 ◽

Vol 17 (10) ◽

pp. 1043-1050 ◽

Cited By ~ 25

Author(s):

Simona Ferraioli ◽

Rosarita Tatè ◽

Alessandra Rogato ◽

Maurizio Chiurazzi ◽

Eduardo J. Patriarca

Keyword(s):

Root Hair ◽

Nodule Development ◽

Bacterial Invasion ◽

Meristematic Tissue ◽

Root Hair Deformation ◽

Conditional Mutant ◽

Infection Threads ◽

Induced Mutants ◽

Symbiotic Phenotype ◽

Nodulin Genes

The symbiotic phenotype of five Tn5-induced mutants of Rhizobium etli affected in different anabolic pathways (namely, gluconeogenesis and biosynthesis of lysine, purine, or pyrimidine) was analyzed. These mutants induced, on the root of Phaseolus vulgaris, a normal early sequence of morphogenetics events, including root hair deformation and development of nodule primordia. Later on, however, from the resulting root outgrowths, instead of nodules, one or more ectopic roots (spaced closely related and agravitropic) emerged. Therefore, this group of mutant was collectively called “root inducer” (RIND). It was observed that the RIND-induced infection threads aborted early inside the invaded root hair, and that the resulting abortive nodules lack induction of late nodulin genes. Moreover, experiments performed using a conditional mutant (a methionine-requiring invader) revealed that bacterial invasion plays a key role in the maintenance of the program of nodule development and, in particular, in the differentiation of the most specific symbiotic tissue of globose nodules, the central tissue. These data indicate that, in P. vulgaris, the nodule primordium is a root-specified pro-meristematic tissue.

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Root Hair Deformation Activity of Nodulation Factors and Their Fate on Vicia sativa

PLANT PHYSIOLOGY ◽

10.1104/pp.105.3.787 ◽

1994 ◽

Vol 105 (3) ◽

pp. 787-797 ◽

Cited By ~ 140

Author(s):

R. Heidstra ◽

R. Geurts ◽

H. Franssen ◽

H. P. Spaink ◽

A. van Kammen ◽

...

Keyword(s):

Root Hair ◽

Vicia Sativa ◽

Root Hair Deformation ◽

Nodulation Factors

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Identical Accumulation and Immobilization of Sulfated and Nonsulfated Nod Factors in Host and Nonhost Root Hair Cell Walls

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2003.16.10.884 ◽

2003 ◽

Vol 16 (10) ◽

pp. 884-892 ◽

Cited By ~ 15

Author(s):

Joachim Goedhart ◽

Jean-Jacques Bono ◽

Ton Bisseling ◽

Theodorus W. J. Gadella

Keyword(s):

Hair Cell ◽

Root Hair ◽

Cell Walls ◽

Root Hairs ◽

Sharp Decrease ◽

Biologically Active ◽

Nod Factors ◽

Nod Factor ◽

Root Hair Cell ◽

Root Hair Deformation

Nod factors are signaling molecules secreted by Rhizobium bacteria. These lipo-chitooligosaccharides (LCOs) are required for symbiosis with legumes and can elicit specific responses at subnanomolar concentrations on a compatible host. How plants perceive LCOs is unclear. In this study, using fluorescent Nod factor analogs, we investigated whether sulfated and nonsulfated Nod factors were bound and perceived differently by Medicago truncatula and Vicia sativa root hairs. The bioactivity of three novel sulfated fluorescent LCOs was tested in a root hair deformation assay on M. truncatula, showing bioactivity down to 0.1 to 1 nM. Fluorescence microscopy of plasmolyzed M. truncatula root hairs shows that sulfated fluorescent Nod factors accumulate in the cell wall of root hairs, whereas they are absent from the plasma membrane when applied at 10 nM. When the fluorescent Nod factor distribution in medium surrounding a root was studied, a sharp decrease in fluorescence close to the root hairs was observed, visualizing the remarkable capacity of root hairs to absorb Nod factors from the medium. Fluorescence correlation microscopy was used to study in detail the mobilities of sulfated and nonsulfated fluorescent Nod factors which are biologically active on M. truncatula and V. sativa, respectively. Remarkably, no difference between sulfated and nonsulfated Nod factors was observed: both hardly diffuse and strongly accumulate in root hair cell walls of both M. truncatula and V. sativa. The implications for the mode of Nod factor perception are discussed.

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