Ultrastructural and immunological demonstration of the nodulation of the European Alnus glutinosa (L.) Gaertn. host plant by the North-American Alnus crispa var. mollis Fern, root nodule endophyte

1977 ◽  
Vol 23 (11) ◽  
pp. 1529-1547 ◽  
Author(s):  
M. Lalonde ◽  
A. Quispel
Keyword(s):  
Host Plant ◽  
North American ◽  
Root Nodule ◽  
Light And Electron Microscopy ◽  
Root Hairs ◽  
Alnus Glutinosa ◽  
Bacterial Cells ◽  
Cortical Cells ◽  
Alnus Crispa ◽  
The North

The inoculation of the European Alnus glutinosa (L.) Gaertn. host plant by a crushed-nodule inoculum, prepared with the North-American Alnus crispa var. mollis Fern, root nodule, was successful. Fluorescein- and ferritin-labelled antibodies, specific against the A. crispa var. mollis root nodule endophyte (Lalonde et al. 1975), demonstrated the identity of this endophyte in the resulting nodules. The nodulation process of this abnormal host–endophyte system was studied by light and electron microscopy. An excretion of host blebs containing electron-dense polysaccharide material, resulting in the formation of exo-encapsulation threads containing presumptive endophytic bacterial cells, was associated with deformed root hairs. Originating from an exoen-capsulation thread, the endophyte penetrates the root hair cell and then migrates as a hypha toward the cortical cells of the root. Its migration in the cortical cells of the primary nodule results in the induction of a lateral root which develops as the true nodule. The ultrastructure of the A. crispa var. mollis endophyte developing in the primary and true nodule of the abnormal A. glutinosa host was similar to the one induced inside its normal A. crispa var. mollis host. The actinomycetal intruder was a branched and septate hypha able to produce septate vesicles. The endophyte was always encapsulated in an electron-dense polysaccharide material surrounded by a host plasma membrane envelope. However, in this abnormal host–endophyte system, the number of primary nodules formed per root system was drastically reduced, and their appearance was delayed by 1 to 2 weeks. The delayed nodules were effective in fixing nitrogen and able to support satisfactory plant growth in a nitrogen-free medium.

scholarly journals First records of the North American leafhopper Gyponana mail (Hemiptera: Cicadellidae) invading urban gardens and agroecosystems in Europe

2021 ◽  
pp. 213-219
Author(s):  
Valeria Trivellone ◽  
Vally Forte ◽  
Luisa Filippin ◽  
Christopher H. Dietrich
Keyword(s):  
Phylogenetic Analysis ◽  
Host Plant ◽  
North American ◽  
Male Genitalia ◽  
Morphological Study ◽  
European Population ◽  
Northern Italy ◽  
Urban Gardens ◽  
The North ◽  
Palearctic Region

The Nearctic leafhopper species Gyponana (Gyponana) mali DeLong, 1942 is reported from Europe for the fi rst time and represents the fi rst record of the tribe Gyponini Stål, 1870 (Hemiptera: Cicadellidae: Iassinae: Gyponini) for the Palearctic Region. Specimens were collected in southern Switzerland (Ticino) and two regions of northern Italy (Lombardy and Veneto) in 2015–2019. The preferred host plant in these areas appears to be Cornus sanguinea L. Phylogenetic analysis of the COI barcode sequences grouped one of the European specimens with three individuals of G. (G.) mali from Ontario, Canada. Morphological study indicated that the male genitalia of the European population are intermediate between G. (G.) mali and G. (G.) extenda DeLong, 1942.

Cytological studies of the infection process in nodulating and nonnodulating pea genotypes

1989 ◽  
Vol 67 (8) ◽  
pp. 2435-2443 ◽  
Author(s):  
M. F. Le Gal ◽  
S. L. A. Hobbs
Keyword(s):  
North American ◽  
Rhizobium Leguminosarum ◽  
Root Hairs ◽  
Infection Process ◽  
High Concentration ◽  
Cortical Cells ◽  
Pisum Sativum L ◽  
Infection Threads ◽  
American Strain ◽  
Plant Effect

Pisum sativum L., cv. Afghanistan, does not form nodules with 128C52, a North American strain of Rhizobium leguminosarum. Timing of the abortion of the nodulation process was determined by microscopy in both 'Afghanistan' and nonnodulating 'Trapper,' produced by backcrossing the nonnodulating genes of 'Afghanistan' into 'Trapper,' a North American variety. Three to 5 days after inoculation, we observed deformed roots and localized swellings as well as loosely curled root hairs in these nonnodulating combinations. Rhizobia entered root hairs and epidermal cells, but no infection threads were seen. Cortical cells divided and a nodule meristem was initiated. Some meristematic cells showed abnormal features such as a high concentration of free ribosomes, dilated endoplasmic reticulum often connected to a dilated nuclear envelope, and disrupted mitochondria. Cortical cells around the nodule meristem were devoid of starch grains. Such phenotypes are known to be associated with rhizobial mutants, but in this case a plant effect is responsible.

Nodulation speed of Frankia sp. on Alnus glutinosa, Alnus crispa, and Myrica gale

1985 ◽  
Vol 63 (7) ◽  
pp. 1292-1295 ◽  
Author(s):  
Xavier Nesme ◽  
Philippe Normand ◽  
Francine M. Tremblay ◽  
Maurice Lalonde
Keyword(s):  
Host Plant ◽  
Plant Species ◽  
Host Plants ◽  
Alnus Glutinosa ◽  
Frankia Strain ◽  
Myrica Gale ◽  
Alnus Crispa ◽  
The Mean ◽  
Mean Time

The question of compatibility between actinorhizal host plants and Frankia sp. was addressed using nodulation speed on Alnus spp. seedlings and Myrica gale seedlings. It was found that the speed of nodulation, defined as the mean time taken for the formation of the first prenodule, was a stable phenotype of both the Frankia strains and the host plants and that a distinction between slow-, medium-, and fast-nodulating Frankia strains could be made. The speed of nodulation of a given Frankia strain did not appear to be positively correlated to the original host plant from which isolation was first performed. It was, however, positively correlated with the Frankia strain and with the host plant species used for inoculation. Some optimal host plant – endophyte combinations were thus defined. Pure spore inocula of Frankia and in vitro propagated Alnus glutinosa plantlets were used to confirm that both the host plant and the microbial partners genetically influenced the nodulation process.

Light and electron microscopy of a host–fungus interaction in the roots of some epiphytic ferns from Costa Rica

1995 ◽  
Vol 73 (7) ◽  
pp. 991-996 ◽  
Author(s):  
E. Schmid ◽  
F. Oberwinkler ◽  
L. D. Gómez
Keyword(s):  
Electron Microscopy ◽  
Costa Rica ◽  
Matrix Material ◽  
Light And Electron Microscopy ◽  
Root Hairs ◽  
Host Cells ◽  
Cortical Cells ◽  
Host Fungus ◽  
Hyphal Coils ◽  
Uniform Diameter

The roots of 11 epiphytic fern species from the genera Elaphaglossum, Peltapteris, Hymenophyllum, Grammitis, and Lellingeria were studied by means of light and electron microscopy. All species showed a similar association with an ascomycete that traversed the root hairs and formed intracellular hyphal coils within cytoplasmic epidermal and outer cortical cells. The unbranched fungal hyphae were of a uniform diameter. They were surrounded by a flocculent matrix material and by the host plasmalemma. Cytoplasmic hyphae also occurred within degenerated host cells. The host–fungus interaction showed similarities to Ericoid mycorrhizae. Key words: ferns, mycorrhiza, ascomycete, ultrastructure, Costa Rica.

scholarly journals Distribution, Incidence and Severity of the Catalpa Powdery Mildew Caused by Erysiphe elevata in North-Eastern Romania

2018 ◽  
Vol 10 (4) ◽  
pp. 614-617
Author(s):  
Vasilică C. CHINAN ◽  
Ciprian C. MÂNZU
Keyword(s):  
Powdery Mildew ◽  
Host Plant ◽  
North American ◽  
High Frequency ◽  
Green Spaces ◽  
The North ◽  
North Eastern

Erysiphe elevata is a North American fungus that causes the powdery mildew of Catalpa species. The present study brings new data on the spread of this species in Romania, and given its invasiveness in Europe, the study evaluates the incidence and intensity of the powdery mildew caused to Catalpa bignonioides (Southern catalpa). In 2017, 12 North-Estern Romanian cities where C. bignonioides had been planted in green spaces were investigated. The results have shown that the pathogen is widespread in the North-Estern part of Romania, accompanying the host plant in all of the localities investigated. In addition, the high frequency of the disease, confirms the invasiveness of E. elevata, most affected being the trees that were planted along streets and in public squares. A specimen of E. elevata was sequenced and the BLAST results revealed that it is identical to samples from France and Korea.

The genus Alucita in North America, with description of two new species (Lepidoptera: Alucitidae)

2004 ◽  
Vol 136 (4) ◽  
pp. 553-579 ◽  
Author(s):  
Bernard Landry ◽  
Jean-François Landry
Keyword(s):  
New York ◽  
British Columbia ◽  
New Species ◽  
North America ◽  
Host Plant ◽  
North American ◽  
Type Locality ◽  
Widespread Species ◽  
The North ◽  
Two New Species

AbstractThe North American fauna of Alucitidae is shown to include three widespread species: Alucita montana Barnes et Lindsey, 1921 (nec Cockerell), Alucita adriendenisisp. nov. (type locality: Manitoulin Island, Ontario, Canada), and Alucitalalanneisp. nov. (type locality: Maynooth, Ontario, Canada). Alucita hexadactyla (L., 1758) and A. huebneri Wallengren, 1862 do not occur in North America. The three North American species are described and illustrated. Alucita montana is found from southwestern Quebec and Vermont, west to British Columbia, and south to Arizona, California, and Texas; its caterpillar is associated with Symphoricarpos spp. (Caprifoliaceae). Alucita adriendenisi is known from northwestern Quebec and New York, west to Alberta and the Northwest Territories, with more southern populations (isolated?) in West Virginia, Arizona, and Texas; its caterpillar feeds on flowers of Lonicera dioica L. (Caprifoliaceae) in Michigan. Alucita lalannei has been found in Ontario, Manitoba, and Alberta, Canada; its host plant is unknown.

Root hair infection process and myconodule formation on Alnus incana by Penicillium nodositatum

1994 ◽  
Vol 72 (7) ◽  
pp. 955-962 ◽  
Author(s):  
Jeanine Sequerra ◽  
André Capellano ◽  
Monique Faure-Raynard ◽  
André Moiroud
Keyword(s):  
Root Hair ◽  
Light And Electron Microscopy ◽  
Root Hairs ◽  
Infection Process ◽  
Initial Contact ◽  
Alnus Incana ◽  
Cortical Cells ◽  
Infected Root ◽  
Root Hair Infection ◽  
Polysaccharide Matrix

Penicillium nodositatum infects the roots of alder trees and induces the formation of structures called myconodules, which are similar to young actinorhizae. Root infection of Alnus incana by P. nodositatum as well as myconodule development were studied by light and electron microscopy and observations were compared with those described for the infection by Frankia spp. We have established an obvious homology between the early steps of the infection caused by both microorganisms. The presence of the fungus near the roots induces deformation of root hairs. The infection site is probably localized in a folding of a deformed hair. As soon as hyphae penetrate into the hair, they become enclosed in a polysaccharide matrix. Initially, P. nodositatum colonizes a region near the infected root hair that may correspond to a slightly developed prenodule. Then a nodular primordium is initiated at some distance from the initial contact and the new nodular cortex is invaded by the fungus. The zone of infection is limited to the cortical cells by a barrier of tannins. Myconodules remain small and unilobed and have an outer morphology similar to that of an incompatible Frankia nodule. Key words: Alnus, myconodule formation, Penicillium, root hair infection.

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