ROP6 is involved in root hair deformation induced by Nod factors in Lotus japonicus

2016 ◽  
Vol 108 ◽  
pp. 488-498 ◽  
Author(s):  
Danxia Ke ◽  
Xiangyong Li ◽  
Yapeng Han ◽  
Lin Cheng ◽  
Hongyu Yuan ◽  
...  
Keyword(s):  
Root Hair ◽  
Lotus Japonicus ◽  
Nod Factors ◽  
Root Hair Deformation

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

2003 ◽  
Vol 16 (10) ◽  
pp. 884-892 ◽  
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.

The expression of LjROP4 is required for rhizobial infection in Lotus japonicus

2019 ◽  
Vol 99 (6) ◽  
pp. 897-904
Author(s):  
Danxia Ke ◽  
Kunpeng Peng
Keyword(s):  
Vascular Bundle ◽  
Root Hair ◽  
Molecular Mechanisms ◽  
Lotus Japonicus ◽  
Gus Activity ◽  
Nodule Development ◽  
Root Tip ◽  
Symbiotic Interaction ◽  
Lateral Root Primordia ◽  
Root Hair Deformation

Increasing evidence suggests that Rho of plant (ROP) GTPases play important roles in the rhizobium–legume symbiotic nodulation, but the molecular mechanisms of their regulation in symbiosis remain poorly understood. In this study, we showed that ROP4 in Lotus japonicus (LjROP4) is involved in the symbiotic interaction between L. japonicus and Mesorhizobium loti. Tissue expression analysis showed that LjROP4 expressed highly in the root. Histochemical staining analysis showed that after rhizobia inoculation, GUS reporter activity increased in the root vascular bundle, root tip, and lateral root primordia. During nodule development, GUS activity was detected in the cortex of nodule primordia and young nodules. In the mature nodules, GUS activity was detected only in the vascular bundle. Compared with the control, the overexpression of ROP4 and ROP4-CA produced much more pronounced root hair swelling and curling induced by M. loti. The infection event and nodule number noticeably increased, which was consistent with this promotion of root hair deformation. Moreover, RNA interference of LjROP4 produced opposite phenotypes. These data suggest that LjROP4 is required for root hair deformation during rhizobial infection. Thus, our study provides important information about root hair deformation responses induced by nod factors in the early stages of symbiotic interaction.

scholarly journals Rapid, Plateau-like Increases in Intracellular Free Calcium Are Associated with Nod-Factor—Induced Root-Hair Deformation

1997 ◽  
Vol 10 (7) ◽  
pp. 791-802 ◽  
Author(s):  
Christoph A. Gehring ◽  
Helen R. Irving ◽  
Akram A. Kabbara ◽  
Roger W. Parish ◽  
Nawal M. Boukli ◽  
...  
Keyword(s):  
Root Hair ◽  
Root Hairs ◽  
Epidermal Cells ◽  
Intracellular Free Calcium ◽  
Free Calcium ◽  
Broad Host Range ◽  
Nod Factors ◽  
Root Cortex ◽  
Cellular Events ◽  
Root Hair Deformation

Rhizobia excrete variously substituted lipo-oligosaccha-ride Nod factors into the legume rhizosphere. Homologous legumes respond to these signals through deformation of the root hairs and the development of nodulation foci in the root cortex. Cellular events in root hairs from the susceptible zone of nearly mature root hairs were studied in root segments loaded with the calcium indicators Fura-2 or Fluo-3. Application of 10-9 M Nod factors of the broad-host-range Rhizobium sp. NGR234 to the homologous legume Vigna unguiculata resulted, within seconds, in plateau-like increases in intracellular free calcium ([Ca2+]i) in the root hairs and root epidermal cells. Nod factors of R. meliloti at 10-9 M caused equally rapid increases in [Ca2+]i in the root hairs and epidermal cells of the nonhost V. unguiculata, and also induced root-hair deformation. The chitin tetramer, N-N′-N″-N′″-tetracetylchitotetraose, which represents the backbone of Nod factors, induced neither root-hair deformation nor changes in [Ca2+]i in V. unguiculata. Root hairs and epidermal cells of the nonlegume non-host Arabidopsis thaliana showed neither [Ca2+]i increases nor root-hair deformation in response to both factors.

Structural and functional comparison of Frankia root hair deforming factor and rhizobia Nod factor

1999 ◽  
Vol 77 (9) ◽  
pp. 1293-1301 ◽  
Author(s):  
Hélène Cérémonie ◽  
Frédéric Debellé ◽  
Maria P Fernandez
Keyword(s):  
Root Hair ◽  
Nod Factors ◽  
Frankia Strain ◽  
Nod Factor ◽  
Combined Nitrogen ◽  
Nitrogen Effect ◽  
Root Hair Deformation ◽  
Butanol Extraction ◽  
Layer Chromatography

The infectious processes of the Frankia-Alnus and Rhizobium-legume symbioses present strong similarities, suggesting the existence of analogies between Frankia root hair deforming factor and rhizobia Nod factors. Biochemical and functional analogies were tested using ACoN24d Frankia strain. The putative chitin-like nature of the Frankia deforming factor was explored by (i) gas chromatography coupled to mass spectrometry and thin layer chromatography, after radioactive labeling of the culture for detection of chitin oligomers, and (ii) following the root hair deforming activity of the supernatant after discriminating treatments (temperature, chitinase, butanol extraction). In parallel, the functional analogy was questioned by testing the mitotic activity of the Frankia supernatant onAlnus glutinosa (L.) roots. The implication in the symbiotic process of the Frankia factor was indirectly explored by testing the effect of a nodulation inhibitor (combined nitrogen) on root hair deformation. The studies of the combined nitrogen effect on root hair deformation indicate that the deformation induced in vitro by the Frankia factor is linked to the symbiotic process. Moreover, the various approaches used suggest that rhizobia Nod factors and Frankia root hair deforming factor are two structurally divergent symbiotic factors. However, functionnal differences between Frankia root hair factor and the Nod factors have to be confirmed.Key words: Frankia, root hair deforming factor, Nod factor, actinorhizal plants.

Ethylene provides positional information on cortical cell division but is not involved in Nod factor-induced root hair tip growth in Rhizobium-legume interaction

Development ◽  
1997 ◽  
Vol 124 (9) ◽  
pp. 1781-1787 ◽  
Author(s):  
R. Heidstra ◽  
W.C. Yang ◽  
Y. Yalcin ◽  
S. Peck ◽  
A.M. Emons ◽  
...  
Keyword(s):  
Cell Division ◽  
Root Hair ◽  
Rhizobium Leguminosarum ◽  
Tip Growth ◽  
Cortical Cell ◽  
Acc Oxidase ◽  
Positional Information ◽  
Nod Factors ◽  
Nod Factor ◽  
Root Hair Deformation

Nod factors secreted by Rhizobium leguminosarum bv. viciae induce root hair deformation, involving a reinitiation of tip growth, and the formation of nodule primordia in Vicia sativa (vetch). Ethylene is a potent inhibitor of cortical cell division, an effect that can be counteracted by applying silver ions (Ag+) or aminoethoxy-vinylglycine (AVG). In contrast to the inhibitory effect on cortical cell division, ethylene promotes the formation of root hairs (which involves tip growth) in the root epidermis of Arabidopsis. We investigate the possible paradox concerning the action of ethylene, putatively promoting Nod factor induced tip growth whilst, at the same time, inhibiting cortical cell division. We show, by using the ethylene inhibitors AVG and Ag+, that ethylene has no role in the reinitiation of root hair tip growth induced by Nod factors (root hair deformation) in vetch. However, root hair formation is controlled, at least in part, by ethylene. Furthermore, we show that ACC oxidase, which catalizes the last step in ethylene biosynthesis, is expressed in the cell layers opposite the phloem in that part of the root where nodule primordia are induced upon inoculation with Rhizobium. Therefore, we test whether endogenously produced ethylene provides positional information controlling the site where nodule primordia are formed by determining the position of nodules formed on pea roots grown in the presence of AVG or Ag+.

scholarly journals Identification of Symbiotically Defective Mutants of Lotus japonicus Affected in Infection Thread Growth

2006 ◽  
Vol 19 (12) ◽  
pp. 1444-1450 ◽  
Author(s):  
Fabien Lombardo ◽  
Anne B. Heckmann ◽  
Hiroki Miwa ◽  
Jillian A. Perry ◽  
Koji Yano ◽  
...  
Keyword(s):  
Root Hair ◽  
Plant Cell Wall ◽  
Plant Root ◽  
Lotus Japonicus ◽  
Cortical Cell ◽  
Host Cells ◽  
Infection Thread ◽  
Mycorrhizal Symbiosis ◽  
Symbiotic Interaction ◽  
Infection Threads

During the symbiotic interaction between legumes and rhizobia, the host cell plasma membrane and associated plant cell wall invaginate to form a tunnel-like infection thread, a structure in which bacteria divide to reach the plant root cortex. We isolated four Lotus japonicus mutants that make infection pockets in root hairs but form very few infection threads after inoculation with Mesorhizobium loti. The few infection threads that did initiate in the mutants usually did not progress further than the root hair cell. These infection-thread deficient (itd) mutants were unaffected for early symbiotic responses such as calcium spiking, root hair deformation, and curling, as well as for the induction of cortical cell division and the arbuscular mycorrhizal symbiosis. Complementation tests and genetic mapping indicate that itd2 is allelic to Ljsym7, whereas the itd1, itd3, and itd4 mutations identified novel loci. Bacterial release into host cells did occur occasionally in the itd1, itd2, and itd3 mutants suggesting that some infections may succeed after a long period and that infection of nodule cells could occur normally if the few abnormal infection threads that were formed reached the appropriate nodule cells.

Root hair deformation in the infection process of Alnus rubra

1983 ◽  
Vol 61 (11) ◽  
pp. 2863-2876 ◽  
Author(s):  
Alison M. Berry ◽  
John G. Torrey
Keyword(s):  
Root Hair ◽  
Cell Walls ◽  
Root Hairs ◽  
Infection Process ◽  
Alnus Rubra ◽  
Pseudomonas Cepacia ◽  
Developmental Studies ◽  
Experimental Conditions ◽  
Root Hair Cell ◽  
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.

scholarly journals 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

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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