Anatomical comparison of wild-type and non-nodulating mutant chickpea (Cicer arietinum)

1990 ◽  
Vol 68 (6) ◽  
pp. 1201-1207 ◽  
Author(s):  
Leslie J. Matthews ◽  
Thomas M. Davis
Keyword(s):  
Cell Division ◽  
Cicer Arietinum ◽  
Root Hair ◽  
Root Nodule ◽  
Cortical Cell ◽  
Infection Process ◽  
Nodule Formation ◽  
Cell Infection ◽  
Infection Threads ◽  
Nodule Symbiosis

Non-nodulating chickpea (Cicer arietinum L.) mutant PM233B was characterized anatomically via comparison with its normally nodulating parent line ICC 640. Root hair and cortical cell infection threads, cortical cell division centers, and nodule formation were observed by light microscopy in serial root sections of ICC 640, but were absent in PM233B. Scanning electron microscope observations of inoculated root sections showed that ICC 640 and PM233B were indistinguishable in adsorption of chickpea Rhizobium strain CC1192. Thus, the rhizobial infection process was blocked in PM233B at a stage subsequent to root hair adsorption of bacteria, but prior to initiation of infection threads and root cortical cell division. Reciprocal shoot grafts between ICC 640 and PM233B demonstrated that the non-nodulation phenotype of PM233B was controlled by the root, and not the shoot, genotype. Key words: chickpea, Cicer arietinum, root nodule, symbiosis, non-nodulating mutant.

Early events in the infection of soybean by Rhizobium japonicum. Time course and cytology of the initial infection process

1982 ◽  
Vol 60 (2) ◽  
pp. 152-161 ◽  
Author(s):  
B. Gillian Turgeon ◽  
Wolfgang D. Bauer
Keyword(s):  
Root Hair ◽  
Time Course ◽  
Cortical Cell ◽  
Root Hairs ◽  
Infection Process ◽  
Infection Thread ◽  
Rhizobium Japonicum ◽  
Outer Cortex ◽  
Light Microscope Level ◽  
Infection Threads

The time course of early infection events in Glycine max following inoculation with Rhizobium japonicum is described. Bacteria became attached to epidermal cells and root hairs within minutes of inoculation. Marked root hair curling occurred within 12 h. Infection thread formation was visible at the light microscope level of resolution about 24 h after inoculation. Infections were observed in short, tightly curled root hairs. These root hairs had not yet emerged at the time of inoculation. Infection threads appeared to originate in pockets formed by contact of the cell wall of the curled root hair with itself. Infection threads in the hairs were multiple and (or) branched. By 48 h, the infection thread(s) had progressed to the base of the root hair but had not yet penetrated into the cortex. Increases in cortical cell cytoplasm and in mitotic division occurred in advance of the penetrating infection thread. A nodule meristem developed in the outer cortex next to the infected root hair by 4 days and was accompanied by cell division across the cortex.

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.

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

1997 ◽  
Vol 10 (2) ◽  
pp. 215-220 ◽  
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.

scholarly journals A New Species of Devosia That Forms a Unique Nitrogen-Fixing Root-Nodule Symbiosis with the Aquatic Legume Neptunia natans (L.f.) Druce

2002 ◽  
Vol 68 (11) ◽  
pp. 5217-5222 ◽  
Author(s):  
Raul Rivas ◽  
Encarna Velázquez ◽  
Anne Willems ◽  
Nieves Vizcaíno ◽  
Nanjappa S. Subba-Rao ◽  
...  
Keyword(s):  
Root Nodule ◽  
Root Nodules ◽  
Infection Process ◽  
Nitrogen Fixing ◽  
Rhizobium Tropici ◽  
Rdna Sequences ◽  
Root Nodule Symbiosis ◽  
16S Rdna Sequences ◽  
The Common ◽  
Nodule Symbiosis

ABSTRACT Rhizobia are the common bacterial symbionts that form nitrogen-fixing root nodules in legumes. However, recently other bacteria have been shown to nodulate and fix nitrogen symbiotically with these plants. Neptunia natans is an aquatic legume indigenous to tropical and subtropical regions and in African soils is nodulated by Allorhizobium undicola. This legume develops an unusual root-nodule symbiosis on floating stems in aquatic environments through a unique infection process. Here, we analyzed the low-molecular-weight RNA and 16S ribosomal DNA (rDNA) sequence of the same fast-growing isolates from India that were previously used to define the developmental morphology of the unique infection process in this symbiosis with N. natans and found that they are phylogenetically located in the genus Devosia, not Allorhizobium or Rhizobium. The 16S rDNA sequences of these two Neptunia-nodulating Devosia strains differ from the only species currently described in that genus, Devosia riboflavina. From the same isolated colonies, we also located their nodD and nifH genes involved in nodulation and nitrogen fixation on a plasmid of approximately 170 kb. Sequence analysis showed that their nodD and nifH genes are most closely related to nodD and nifH of Rhizobium tropici, suggesting that this newly described Neptunia-nodulating Devosia species may have acquired these symbiotic genes by horizontal transfer.

A shared gene drives lateral root development and root nodule symbiosis pathways in Lotus

Science ◽  
2019 ◽  
Vol 366 (6468) ◽  
pp. 1021-1023 ◽  
Author(s):  
Takashi Soyano ◽  
Yoshikazu Shimoda ◽  
Masayoshi Kawaguchi ◽  
Makoto Hayashi
Keyword(s):  
Root Development ◽  
Lateral Root ◽  
Root Nodule ◽  
Root Nodules ◽  
Lotus Japonicus ◽  
Cortical Cell ◽  
Cortical Cells ◽  
Lateral Root Development ◽  
Lateral Organ ◽  
Nodule Symbiosis

Legumes develop root nodules in symbiosis with nitrogen-fixing rhizobial bacteria. Rhizobia evoke cell division of differentiated cortical cells into root nodule primordia for accommodating bacterial symbionts. In this study, we show that NODULE INCEPTION (NIN), a transcription factor in Lotus japonicus that is essential for initiating cortical cell divisions during nodulation, regulates the gene ASYMMETRIC LEAVES 2-LIKE18/LATERAL ORGAN BOUNDARIES DOMAIN16a (ASL18/LBD16a). Orthologs of ASL18/LBD16a in nonlegume plants are required for lateral root development. Coexpression of ASL18a and the CCAAT box–binding protein Nuclear Factor-Y (NF-Y) subunits, which are also directly targeted by NIN, partially suppressed the nodulation-defective phenotype of L. japonicusdaphne mutants, in which cortical expression of NIN was attenuated. Our results demonstrate that ASL18a and NF-Y together regulate nodule organogenesis. Thus, a lateral root developmental pathway is incorporated downstream of NIN to drive nodule symbiosis.

The Rhizobium trap: root hair curling in root–nodule symbiosis

1992 ◽  
pp. 267-284 ◽  
Author(s):  
J. W. Kijne ◽  
R. Bakhuizen ◽  
A. A. N. Van Brussel ◽  
H. C. J. Canter Cremers ◽  
C. L. Diaz ◽  
...  
Keyword(s):  
Root Hair ◽  
Root Nodule ◽  
Root Nodule Symbiosis ◽  
Hair Curling ◽  
Root Hair Curling ◽  
Nodule Symbiosis

scholarly journals Sinorhizobium meliloti Mutants Deficient in Phosphatidylserine Decarboxylase Accumulate Phosphatidylserine and Are Strongly Affected during Symbiosis with Alfalfa

2008 ◽  
Vol 190 (20) ◽  
pp. 6846-6856 ◽  
Author(s):  
Miguel Angel Vences-Guzmán ◽  
Otto Geiger ◽  
Christian Sohlenkamp
Keyword(s):  
Sinorhizobium Meliloti ◽  
Minimal Medium ◽  
Root Nodule ◽  
Membrane Lipids ◽  
Nodule Formation ◽  
Deficient Mutant ◽  
Nitrogen Fixing ◽  
Wild Type ◽  
Root Nodule Symbiosis ◽  
Nodule Symbiosis

ABSTRACT Sinorhizobium meliloti contains phosphatidylglycerol, cardiolipin, phosphatidylcholine, and phosphatidylethanolamine (PE) as major membrane lipids. PE is formed in two steps. In the first step, phosphatidylserine synthase (Pss) condenses serine with CDP-diglyceride to form phosphatidylserine (PS), and in the second step, PS is decarboxylated by phosphatidylserine decarboxylase (Psd) to form PE. In this study we identified the sinorhizobial psd gene coding for Psd. A sinorhizobial mutant deficient in psd is unable to form PE but accumulates the anionic phospholipid PS. Properties of PE-deficient mutants lacking either Pss or Psd were compared with those of the S. meliloti wild type. Whereas both PE-deficient mutants grew in a wild-type-like manner on many complex media, they were unable to grow on minimal medium containing high phosphate concentrations. Surprisingly, the psd-deficient mutant could grow on minimal medium containing low concentrations of inorganic phosphate, while the pss-deficient mutant could not. Addition of choline to the minimal medium rescued growth of the pss-deficient mutant, CS111, to some extent but inhibited growth of the psd-deficient mutant, MAV01. When the two distinct PE-deficient mutants were analyzed for their ability to form a nitrogen-fixing root nodule symbiosis with their alfalfa host plant, they behaved strikingly differently. The Pss-deficient mutant, CS111, initiated nodule formation at about the same time point as the wild type but did form about 30% fewer nodules than the wild type. In contrast, the PS-accumulating mutant, MAV01, initiated nodule formation much later than the wild type and formed 90% fewer nodules than the wild type. The few nodules formed by MAV01 seemed to be almost devoid of bacteria and were unable to fix nitrogen. Leaves of alfalfa plants inoculated with the mutant MAV01 were yellowish, indicating that the plants were starved for nitrogen. Therefore, changes in lipid composition, including the accumulation of bacterial PS, prevent the establishment of a nitrogen-fixing root nodule symbiosis.

scholarly journals The monomeric GTPase RabA2 is required for progression and maintenance of membrane integrity of infection threads during root nodule symbiosis

2017 ◽  
Vol 93 (6) ◽  
pp. 549-562 ◽  
Author(s):  
Virginia Dalla Via ◽  
Soledad Traubenik ◽  
Claudio Rivero ◽  
O. Mario Aguilar ◽  
María Eugenia Zanetti ◽  
...  
Keyword(s):  
Root Nodule ◽  
Membrane Integrity ◽  
Root Nodule Symbiosis ◽  
Infection Threads ◽  
Nodule Symbiosis

scholarly journals SHORT-ROOT paralogs mediate feedforward regulation of D-type cyclin to promote nodule formation in soybean

2022 ◽  
Vol 119 (3) ◽  
pp. e2108641119
Author(s):  
Chunhua Wang ◽  
Meng Li ◽  
Yang Zhao ◽  
Nengsong Liang ◽  
Haiyang Li ◽  
...  
Keyword(s):  
Cell Division ◽  
Vascular Tissue ◽  
De Novo ◽  
Cortical Cell ◽  
Nodule Formation ◽  
Cytokinin Signaling ◽  
Short Root ◽  
Cell Divisions ◽  
Early Nodulin ◽  
Nodulin Genes

Nitrogen fixation in soybean takes place in root nodules that arise from de novo cell divisions in the root cortex. Although several early nodulin genes have been identified, the mechanism behind the stimulation of cortical cell division during nodulation has not been fully resolved. Here we provide evidence that two paralogs of soybean SHORT-ROOT (GmSHR) play vital roles in soybean nodulation. Expression of GmSHR4 and GmSHR5 (GmSHR4/5) is induced in cortical cells at the beginning of nodulation, when the first cell divisions occur. The expression level of GmSHR4/5 is positively associated with cortical cell division and nodulation. Knockdown of GmSHR5 inhibits cell division in outer cortical layers during nodulation. Knockdown of both paralogs disrupts the cell division throughout the cortex, resulting in poorly organized nodule primordia with delayed vascular tissue formation. GmSHR4/5 function by enhancing cytokinin signaling and activating early nodulin genes. Interestingly, D-type cyclins act downstream of GmSHR4/5, and GmSHR4/5 form a feedforward loop regulating D-type cyclins. Overexpression of D-type cyclins in soybean roots also enhanced nodulation. Collectively, we conclude that the GmSHR4/5-mediated pathway represents a vital module that triggers cytokinin signaling and activates D-type cyclins during nodulation in soybean.

scholarly journals Intragenic Complementation of Cellulose Synthase-Like D1 alleles in Root Hair Development

2020 ◽  
Author(s):  
Bogumil J. Karas ◽  
Loretta Ross ◽  
Mara Novero ◽  
Lisa Amyot ◽  
Sayaka Inada ◽  
...  
Keyword(s):  
Root Hair ◽  
Root Nodule ◽  
Lotus Japonicus ◽  
Cellulose Synthase ◽  
Variable Length ◽  
Root Hair Development ◽  
Root Nodule Symbiosis ◽  
Intragenic Complementation ◽  
Hair Development ◽  
Nodule Symbiosis

AbstractRoot hair cells form the primary interface of plants with the soil environment, playing key roles in nutrient uptake and plant defense. In addition, they are typically the first cells infected by nitrogen-fixing soil bacteria during the root nodule symbiosis. Here we report a role for the Cellulose Synthase-Like D1 (CSLD1) gene in root hair development in Lotus japonicus. CSLD1 belongs to the cellulose synthase protein family that includes cellulose synthases, and cellulose synthase-like proteins, the latter thought to be involved in the biosynthesis of hemicellulose. We describe 11 csld1 mutant alleles that have either short (Ljcsld1-1) or variable length roots hairs (Ljcsld1-2 to 11). Examination of Ljcsld1-1 and one variable-length root hair mutant, Ljcsld1-6 showed increased root hair cell wall thickness, which in Ljcsld1-1 was more pronounced, suggesting a possible link with the defect in root nodule symbiosis. In addition, Ljcsld1-1 heterozygotes had intermediate root hair lengths, between those of wild type and the homozygotes. Intragenic complementation was observed between alleles with mutations in the N-terminal domain and other alleles, suggesting modularity of CSLD1 function and that it may operate as a homodimer or multimer.One sentence summaryThis research describes novel gain- and loss-of-function mutations at the Lotus japonicus CELLULOSE SYNTHASE-LIKE D1 locus and analyzes their impact on root hair development.

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