Rhizobium infection threads in root hairs of Glycine max (L.) Merr., Glycine soja Sieb. & Zucc, and Vigna unguiculata (L.) Walp.

1983 ◽  
Vol 29 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Steven G. Pueppke

Eight lines of soybean (Glycine max), four of wild soybean (Glycine soja), and one cowpea (Vigna unguiculata) cultivar were inoculated with 18 Rhizobium strains. After 4 days, root hairs were examined for infection threads. Threads were produced by all hosts but exclusively in nodulating combinations. Only Rhizobium sp. strains 3G4b9a and 3G4b19 were inconsistent; they nodulated soybean and G. soja in some experiments, but rarely formed infection threads. Soybean and G. soja were indistinguishable in their interactions with rhizobia, as were lele soybean lines (genetically lack soybean lectin), Hardee soybean (contains the noduation-influencing genes Rj2 and Rj3), and several other soybean cultivars. Threads formed in cowpea with all of the R. japonicum strains and most Rhizobium sp. but not with R. lupini. Infection of all three host species occurred in portions of the primary root containing immature or no root hairs at the time of inoculation; proximal tissues having elongated root hairs lacked infection threads. Infected root hairs were short and commonly shaped like question marks. Threads usually branched and sometimes intertwined prior to elongation into the basal portion of root hairs.

2002 ◽  
Vol 184 (3) ◽  
pp. 831-839 ◽  
Author(s):  
Hari B. Krishnan

ABSTRACT Sinorhizobium fredii USDA257 forms nitrogen-fixing nodules on soybean (Glycine max [L.] Merr.) in a cultivar-specific manner. This strain forms nodules on primitive soybean cultivars but fails to nodulate agronomically improved North American cultivars. Soybean cultivar specificity is regulated by the nolXWBTUV locus, which encodes part of a type III secretion system (TTSS). NolX, a soybean cultivar specificity protein, is secreted by TTSS and shows homology to HrpF of the plant pathogen Xanthomonas campestris pv. vesicatoria. It is not known whether NolX functions at the bacterium-plant interface or acts inside the host cell. Antibodies raised against S. fredii USDA257 NolX were used in immunocytochemical studies to investigate the subcellular localization of this protein. Immunostaining of paraffin-embedded sections of developing soybean and cowpea (Vigna unguiculata [L.] Walp) nodules revealed localization of NolX in the infection threads. Protein A-gold immunocytochemical localization studies utilizing affinity-purified NolX antibodies revealed specific deposition of gold particles in the fibrillar material inside infection threads. Similar immunogold localization studies failed to detect NolX in thin sections of mature soybean and cowpea nodules. The results from this study indicate that NolX is expressed in planta only during the early stages of nodule development.


1985 ◽  
Vol 63 (11) ◽  
pp. 1951-1956 ◽  
Author(s):  
W. H. Fuchsman ◽  
R. G. Palmer

The leghemoglobins from a genetically diverse selection of 69 cultivated soybean (Glycine max (L.) Merr.) cultivars and plant introductions and 18 wild soybean (Glycine soja Sieb. & Zucc.) plant introductions all consist of the same set of major leghemoglobins (a, c1, c2, c3), as determined by analytical isoelectric focusing. The conservation of both leghemoglobin heterogeneity and also all four major leghemoglobin structures provides strong circumstantial evidence that leghemoglobin heterogeneity is functional. Glycine max and G. soja produced the same leghemoglobins in the presence of Bradyrhizobium japonicum (Kirchner) Jordan and in the presence of fast-growing Rhizobium japonicum.


2020 ◽  
Vol 12 (9) ◽  
pp. 14
Author(s):  
Fengjuan Niu ◽  
Qiyan Jiang ◽  
Rui Cheng ◽  
Xianjun Sun ◽  
Zheng Hu ◽  
...  

Clustered Regularly Interspaced Short Palindromic Repeat/CRISPR-associated protein 9 (CRISPR/Cas9) system has been regularly applied for genome editing and gene function identification in wild soybean (Glycine max) cultivars. However, till date no studies have demonstrated successful mutagenesis in wild soybean (Glycine soja) which is the ancestor of Glycine max and rich in stress tolerance genes. In the current study, we report the successful creation of mutations in the loci encoding plasma membrane Na+/H+ antiporter (SOS1) and nonselective cation channels (NSCC) in wild soybean hairy roots using the CRISPR/Cas9 system. Two genes, GsSOS1 and GsNSCC, were mutagenized with frequencies of 28.5% and 39.9%, respectively. Biallelic mutations in GsSOS1 were detected in transgenic hairy roots. GsSOS1 mutants exhibited altered Na+/K+ ratios in the roots under both control and salt-treated conditions. However, no significant effects of GsNSCC mutation on Na+/K+ ratios were observed. RNA-Seq analysis revealed that both GsSOS1 and GsNSCC mutation altered the transcription profiles in mutant roots. Many differentially expressed gene sets that are associated with various cellular functions were identified. Our results demonstrated that CRISPR/Cas9 systems as powerful tools for wild soybean genome editing and would significantly advance the gene mining and functional identification in wild soybean.


2019 ◽  
Vol 20 (15) ◽  
pp. 3745 ◽  
Author(s):  
Ting Jin ◽  
Yangyang Sun ◽  
Ranran Zhao ◽  
Zhong Shan ◽  
Junyi Gai ◽  
...  

Peroxidases play prominent roles in antioxidant responses and stress tolerance in plants; however, their functions in soybean tolerance to salt stress remain unclear. Here, we investigated the role of a peroxidase gene from the wild soybean (Glycine soja), GsPRX9, in soybean tolerance to salt stress. GsPRX9 gene expression was induced by salt treatment in the roots of both salt-tolerant and -sensitive soybean varieties, and its relative expression level in the roots of salt-tolerant soybean varieties showed a significantly higher increase than in salt-sensitive varieties after NaCl treatment, suggesting its possible role in soybean response to salt stress. GsPRX9-overexpressing yeast (strains of INVSc1 and G19) grew better than the control under salt and H2O2 stress, and GsPRX9-overexpressing soybean composite plants showed higher shoot fresh weight and leaf relative water content than control plants after NaCl treatment. Moreover, the GsPRX9-overexpressing soybean hairy roots had higher root fresh weight, primary root length, activities of peroxidase and superoxide dismutase, and glutathione level, but lower H2O2 content than those in control roots under salt stress. These findings suggest that the overexpression of the GsPRX9 gene enhanced the salt tolerance and antioxidant response in soybean. This study would provide new insights into the role of peroxidase in plant tolerance to salt stress.


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 887 ◽  
Author(s):  
Chang-Jie Jiang ◽  
Shoji Sugano ◽  
Sunao Ochi ◽  
Akito Kaga ◽  
Masao Ishimoto

Breeding for resistance to soybean red crown rot (Calonectria ilicicola) has long been hampered by the lack of genetic sources of adequate levels of resistance to use as parents. Mini core collections of soybean (Glycine max) originating from Japan (79 accessions), from around the world (80 accessions), and a collection of wild soybeans (Glycine soja) consisting 54 accessions were evaluated for resistance to C. ilicicola (isolate UH2-1). In the first two sets, average disease severity scores of 4.2 ± 0.28 and 4.6 ± 0.31 on a rating scale from zero for no symptom to 5.0 for seedling death were recorded from the set from Japan and the world. No high levels of resistance were observed in these two sets. On the other hand, disease severity score of 3.8 ± 0.35 for the wild soybean accessions was somewhat lower and exhibited higher levels of resistance compared to the soybean cultivars. Three accessions in the wild soybean collection (Gs-7, Gs-9, and Gs-27) had disease severity score ≤2.5 and showed >70% reduction in fungal growth in the roots compared to soybean control cv. “Enrei”. Further analysis using 10 C. ilicicola isolates revealed that accession Gs-9 overall had a wide range of resistance to all isolates tested, with 37% to 93% reduction in fungal growth relative to the cv. Enrei. These highly resistant wild soybean lines may serve as valuable genetic resources for developing C. ilicicola-resistant soybean cultivars.


1982 ◽  
Vol 28 (7) ◽  
pp. 890-896 ◽  
Author(s):  
Arya K. Bal ◽  
Peter P. Wong

In addition to infection via root hairs, infection threads originating in epidermal cells after colonization of epidermis have been clearly demonstrated in lima beans infected with Rhizobium sp. 127E15, and this double mode of infection possibly accounts for profuse nodulation of the roots. Sloughing off of the outer membrane (cell wall) was detected after release of rhizobia during bacteroid differentiation in effective nodules.


1983 ◽  
Vol 97 (3) ◽  
pp. 787-794 ◽  
Author(s):  
C H Wong ◽  
C E Pankhurst ◽  
A Kondorosi ◽  
W J Broughton

We examined expression of the megaplasmid pRme41b of Rhizobium meliloti in two different Rhizobium sp. Strains and in Agrobacterium tumefaciens. Transfer of pRme41b into these bacteria was facilitated by insertion of a recombinant plasmid coding for mobilization functions of RP4 into the nif region (Kondorosi, A., E. Kondorosi, C.E. Pankhurst, W. J. Broughton, and Z. Banfalvi, 1982, Mol. Gen. Genet., 188:433-439). In all cases, transconjugants formed nodule-like structures on the roots of Medicago sativa. These structures were largely composed of meristematic cells but they were not invaded by bacteria. Bacteria were found only within infection threads in root hairs, and within intercellular spaces of the outermost cells of the structures. The donor strain of R. meliloti containing pAK11 or pAK12 in pRme41b initially produced nodules on M. sativa that did not fix nitrogen (Fix-). In these nodules, bacteria were released from infection threads into the host cells but they did not multiply appreciably. Any bacteroids formed degenerated prematurely. In some cases, however, reversion to a Fix+ phenotype occurred after 4 to 6 wk. Bacteria released into newly infected cells in these nodules showed normal development into bacteriods.


Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 808-811 ◽  
Author(s):  
Y. C. Chiang ◽  
Y. T. Kiang

Five mannose-6-phosphate isomerase (EC 5.3.1.8) variants were observed electrophoretically in cultivated soybeans (Glycine max (L.) Merr.) and wild soybeans (G. soja Sieb. &Zucc.). Four of the five variants differed in the mobility of the two mannose-6-phosphate isomerase bands observed, while the fifth showed no enzyme activity. Several crosses involving different variants were made to study inheritance of the observed variants. The inheritance data showed that the five variants were allelic and controlled by a single locus (Mpi). The five alleles were as follows: Mpi-a (Rf 0.61 and 0.66); Mpi-b (Rf 0.66 and 0.7); Mpi-c (Rf 0.71 and 0.75); Mpi-d (Rf 0.76 and 0.80); and mpi. Mpi-a, Mpi-b, Mpi-c, and Mpi-d are codominant, and the null allele mpi is recessive. The Mpi-b allele is most common while the Mpi-d and mpi alleles are rare in both the cultivated and wild soybean germ plasm from various sources examined.Key words: Glycine max, Glycine soja, isozymes, Mpi, gel electrophoresis, allelic frequency.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 813
Author(s):  
Qianru Chen ◽  
Xianxian Wang ◽  
Xiaolong Yuan ◽  
John Shi ◽  
Chengsheng Zhang ◽  
...  

Wild soybean (Glycine soja Sieb.et Zucc; WS) has been used as a traditional food in China for many years and contains significantly higher levels of isoflavones than cultivated soybean (Glycine max; CS), but the secondary metabolites, including flavonoids and the phenolic composition differences between them, remain unclear. The results showed that WS possessed significantly higher total phenolic and flavonoid content and exhibited better antioxidant and α-glucosidase inhibition activities as well as excellent protective effects against H2O2-induced oxidative injury in a human endothelial cell line. Through metabolomic analysis, 642 metabolites were identified, and 238 showed differential expression, with 151 upregulated and 87 downregulated. A total of 79 flavonoid compounds were identified, 42 of which were upregulated in WS. 2′-Hydroxygenistein, garbanzol, protocatechuic aldehyde, ligustilide, and resveratrol were the most discriminated compounds in WS. The metabolic pathway analysis of differential metabolites related to the biosynthesis of flavonoids and phenolic acids were the biosynthesis of phenylpropanoids, flavonoids, isoflavonoids, flavones, and flavonols. This study substantially elucidated differences in the content of flavonoids and biological activities between WS and CS, which is useful information for the effective utilization of these two black soybean species in food processing.


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