Endoplasmic reticulum-targeted GFP reveals ER remodeling in Mesorhizobium-treated Lotus japonicus root hairs during root hair curling and infection thread formation

PROTOPLASMA ◽  
2013 ◽  
Vol 251 (4) ◽  
pp. 817-826 ◽  
Author(s):  
F. M. Perrine-Walker ◽  
H. Kouchi ◽  
R.W. Ridge
1969 ◽  
Vol 22 (2) ◽  
pp. 413 ◽  
Author(s):  
Phaik Y Yao ◽  
JM Vincent

Thirty-eight cultures of rhizobia and 10 non-rhizobia growing in the root zone of clover (Trifolium glomeratum L.), 5 rhizobia and 3 non-rhizobia in that of lucerne (Medicago sativa L.), and 8 rhizobia in that ofSiratro (Phaseolus atropurpureus DO.) revealed a specific relationship between bacteria and host that determined the kind and degree of deformation of the root hairs.


1969 ◽  
Vol 15 (10) ◽  
pp. 1133-1136 ◽  
Author(s):  
Diana Li ◽  
D. H. Hubbell

The basis for determination of nodulating specificity in Rhizobium–clover associations was investigated. Thirteen strains of rhizobia from eight different cross-inoculation groups were used to inoculate aseptically grown strawberry clover seedlings in slide culture. Microscopic observation revealed that each strain produced characteristic root hair deformation but infection threads and nodules were observed only in the homologous combination. It is concluded that, in rhizobia–clover combinations which nodulate via infection threads, specificity is determined at or before infection thread initiation. Observations of other workers that rhizobia produce a strain-specific substance affecting growth and morphology of legume root hairs were confirmed by results of this study.


2015 ◽  
Vol 167 (4) ◽  
pp. 1233-1242 ◽  
Author(s):  
Joëlle Fournier ◽  
Alice Teillet ◽  
Mireille Chabaud ◽  
Sergey Ivanov ◽  
Andrea Genre ◽  
...  

1994 ◽  
Vol 21 (3) ◽  
pp. 311 ◽  
Author(s):  
J Plazinski ◽  
RW Ridge ◽  
IA Mckay ◽  
MA Djordjevic

Cloned DNA fragments coding for the nodDABC genes of Rhizobium leguminosarum biovar trifolii strain ANU843 were introduced into Rhizobium strains possessing Sym plasmid deletions. These strains were able to: (a) synthesise four butanol-soluble Nod metabolites; (b) affect the normal growth pattern of plant root hairs of a wide range of host and non-host legumes; and (c) induce many root outgrowths on Phaseolus plants. The four Nod metabolites produced by these strains were labelled by supplying cultures with 14C-acetate in the presence of a flavonoid inducer of nod gene expression. In contrast, more than ten Nod metabolites were synthesised by wild-type strains or constructed strains containing the full complement of R. leguminosarum biovar. trifolii nodulation and host specific nodulation genes. Strain ANU845 containing nodDABC did not induce infection threads or nodule initiation sites but distorted and curled cells in plant root hairs. However strain ANU845 induced root outgrowths on beans (Phaseolus vulgaris) that appeared to result from a proliferation of the epidermal tissue. Transfer of plasmids bearing nodDABC to various Gram-negative bacteria, Agrobacterium tumefaciens, Pseudomonas aeruginosa, Lignobacter sp., Azospirillum brasilense and Escherichia coli, and different non-nodulating mutant rhizobia conferred on these strains the ability to cause root-hair curling and distortions. Several strains induced root-hair curling on clover and a range of other non-host legumes. We suggest that the expression of nodDABC in a range of soil bacteria may extend or alter the effects of these soil bacteria on the roots of host plants.


1998 ◽  
Vol 11 (12) ◽  
pp. 1233-1241 ◽  
Author(s):  
Wilbert A. T. van Workum ◽  
Sophie van Slageren ◽  
Anton A. N. van Brussel ◽  
Jan W. Kijne

Mutants of Rhizobium leguminosarum bv. viciae bacteria that are affected in the biosynthesis of exopolysaccharides (EPS) are unable to effectively nodulate their host plants. By studying defined mutants, we show that R. legumi-nosarum bv. viciae strains require EPS for formation of infection threads in Vicia sativa (vetch) as well as for efficient induction of tight root hair curling. Results of coinoculation experiments with the EPS-deficient pssD111 mutant of R. leguminosarum bv. viciae in combination with heterologous EPS-producing strains indicated that vetch has certain structural requirements for rhizobial EPS to function in symbiosis. We hypothesize that EPS accelerates root hair curling and infection to such an extent that rhizobial root penetration precedes a plant defense response.


2017 ◽  
Vol 30 (3) ◽  
pp. 194-204 ◽  
Author(s):  
Yasuyuki Kawaharada ◽  
Euan K. James ◽  
Simon Kelly ◽  
Niels Sandal ◽  
Jens Stougaard

Several hundred genes are transcriptionally regulated during infection-thread formation and development of nitrogen-fixing root nodules. We have characterized a set of Lotus japonicus mutants impaired in root-nodule formation and found that the causative gene, Ern1, encodes a protein with a characteristic APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription-factor domain. Phenotypic characterization of four ern1 alleles shows that infection pockets are formed but root-hair infection threads are absent. Formation of root-nodule primordia is delayed and no normal transcellular infection threads are found in the infected nodules. Corroborating the role of ERN1 (ERF Required for Nodulation1) in nodule organogenesis, spontaneous nodulation induced by an autoactive CCaMK and cytokinin–induced nodule primordia were not observed in ern1 mutants. Expression of Ern1 is induced in the susceptible zone by Nod factor treatment or rhizobial inoculation. At the cellular level, the pErn1:GUS reporter is highly expressed in root epidermal cells of the susceptible zone and in the cortical cells that form nodule primordia. The genetic regulation of this cellular expression pattern was further investigated in symbiotic mutants. Nod factor induction of Ern1 in epidermal cells was found to depend on Nfr1, Cyclops, and Nsp2 but was independent of Nin and Nf-ya1. These results suggest that ERN1 functions as a transcriptional regulator involved in the formation of infection threads and development of nodule primordia and may coordinate these two processes.


1996 ◽  
Vol 23 (3) ◽  
pp. 285 ◽  
Author(s):  
BG Rolfe ◽  
RW Carlson ◽  
RW Ridge ◽  
FB Dazzo ◽  
PF Mateos ◽  
...  

The biological and symbiotic properties of two types of exopolysaccharide deficient (Exo- phenotype) mutants of Rhizobium leguminosarum were investigated. One mutant, a pss1 derivative (ANU437) of R. l. bv. trifolii, produces very low levels of acidic exopolysaccharide (EPS) and of the acidic oligosaccharide (AOS) repeating unit lacking its O-acetyl substituent. The second strain, originally a R. I. bv. viciae derivative, but containing a clover pSym plasmid (Exo-1 mutant ANU54(pBRIAN)), did not produce any EPS polymer or detectable oligosaccharide repeating unit. The Exo- mutants formed no capsules and their growth in laboratory media was comparable to their parent strains but was inhibited by the addition of the phytoalexins medicarpin and kievitone, but not by the phytoalexin pisatin. Both Exo- mutants were slow to induce clover root hair curling (Hac+), and formed growing infection threads (Inf-) only on white clovers. However, the extent of these early symbiotic defects depended on the plant growth conditions used. Both mutants induced small non-nitrogen-fixing (Fix-) nodules on white and subterranean clovers. Within the white clover nodules induced by mutant ANU437, bacteria were released into plant cells. On white clovers at elevated light and temperature conditions, the Exo-1 mutant ANU54(pBRIAN) usually failed to initiate infection threads and thus formed empty nodules which do not contain any bacteria. In addition, this mutant formed only empty nodules without infection threads on subterranean clovers under all growth conditions tested. The outermost layers of plant cells in these empty nodules had thickened cell walls and deposited materials. These experiments show that EPS synthesis is essential for the induction of rapid root hair curling, proper infection thread formation and the ability to sustain the growth of induced nodules on various clovers.


2007 ◽  
Vol 189 (22) ◽  
pp. 8347-8352 ◽  
Author(s):  
Shin Okazaki ◽  
Yoshiyuki Hattori ◽  
Kazuhiko Saeki

ABSTRACT The purB and purH mutants of Mesorhizobium loti exhibited purine auxotrophy and nodulation deficiency on Lotus japonicus. In the presence of adenine, only the purH mutant induced nodule formation and the purB mutant produced few infection threads, suggesting that 5-aminoimidazole-4-carboxamide ribonucleotide biosynthesis catalyzed by PurB is required for the establishment of symbiosis.


2011 ◽  
Vol 24 (11) ◽  
pp. 1333-1344 ◽  
Author(s):  
Evgenia Ovchinnikova ◽  
Etienne-Pascal Journet ◽  
Mireille Chabaud ◽  
Viviane Cosson ◽  
Pascal Ratet ◽  
...  

A successful nitrogen-fixing symbiosis requires the accommodation of rhizobial bacteria as new organelle-like structures, called symbiosomes, inside the cells of their legume hosts. Two legume mutants that are most strongly impaired in their ability to form symbiosomes are sym1/TE7 in Medicago truncatula and sym33 in Pisum sativum. We have cloned both MtSYM1 and PsSYM33 and show that both encode the recently identified interacting protein of DMI3 (IPD3), an ortholog of Lotus japonicus (Lotus) CYCLOPS. IPD3 and CYCLOPS were shown to interact with DMI3/CCaMK, which encodes a calcium- and calmodulin-dependent kinase that is an essential component of the common symbiotic signaling pathway for both rhizobial and mycorrhizal symbioses. Our data reveal a novel, key role for IPD3 in symbiosome formation and development. We show that MtIPD3 participates in but is not essential for infection thread formation and that MtIPD3 also affects DMI3-induced spontaneous nodule formation upstream of cytokinin signaling. Further, MtIPD3 appears to be required for the expression of a nodule-specific remorin, which controls proper infection thread growth and is essential for symbiosome formation.


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