scholarly journals Identification of Rice Seed-Derived Fusarium spp. and Development of LAMP Assay against Fusarium fujikuroi

Pathogens ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Hubiao Jiang ◽  
Na Wu ◽  
Shaomin Jin ◽  
Temoor Ahmed ◽  
Hui Wang ◽  
...  

Fusarium species are important seedborne pathogens that cause rice bakanae disease (RBD). In this study, 421 strains were isolated from 25 rice samples collected from Zhejiang, Anhui, and Jiangxi provinces of China. Furthermore, 407 isolates were identified as F. fujikuroi (80.05% isolation frequency), F. proliferatum (8.31%), F. equiseti (5.94%), F. incarnatum (2.61%), F. andiyazi (0.95%), and F. asiaticum (0.48%) based on morphology and translation elongation factor 1-alpha (TEF1-α) gene. Phylogenetic analysis of combined sequences of the RNA polymerase II largest subunit (RPB1), RNA polymerase II second largest subunit (RPB2), TEF1-α gene, and ribosomal DNA (rDNA) internal transcribed spacer (ITS) showed that 17 representative strains were attributed to six species. Pathogenicity tests showed that representative isolates possessed varying ability to cause symptoms of bakanae on rice seedlings. Moreover, the seed germination assay revealed that six isolates had different effects, such as inhibition of seed germination, as well as seed and bud rot. The loop mediated isothermal amplification (LAMP)-based assay were developed for the detection of F. fujikuroi. According to sequences of desaturase-coding gene promoter, a species-specific marker desM231 was developed for the detection of F. fujikuroi. The LAMP assay using seeds collected from field was validated, and diagnostics developed are efficient, rapid, and sensitive.

Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 472
Author(s):  
Marcele Vermeulen ◽  
Lisa A. Rothmann ◽  
Wijnand J. Swart ◽  
Marieka Gryzenhout

Trials are currently being conducted in South Africa to establish Amaranthus cruentus as a new pseudocereal crop. During recent surveys, Fusarium species were associated with weevil damage in A. cruentus fields. Preliminary studies showed that some of these Fusarium species grouped into two distinct clades within the F. fujikuroi species complex. The aim of this study was to characterize these isolates based on the morphology and phylogeny of the translation elongation factor 1α (TEF1α) gene region, ß-tubulin 2 (ßT) gene region and RNA polymerase II subunit (RPB2), and to determine if these isolates are pathogenic to A. cruentus. Phylogenetic and morphological studies showed that these two clades represent two novel species described here as F. casha and F. curculicola. Both species were shown to have the potential to be pathogenic to A. cruentus during routine greenhouse inoculation tests. While isolations indicate a possible association between these two species and weevils, further research is needed to understand this association and the role of weevils in disease development involving F. casha and F. curculicola in A. cruentus.


Author(s):  
N. Yilmaz ◽  
M. Sandoval-Denis ◽  
L. Lombard ◽  
C.M. Visagie ◽  
B.D. Wingfield ◽  
...  

The Fusarium fujikuroi species complex (FFSC) includes more than 60 phylogenetic species (phylospecies) with both phytopathological and clinical importance. Because of their economical relevance, a stable taxonomy and nomenclature is crucial for species in the FFSC. To attain this goal, we examined type specimens and representative cultures of several species by employing morphology and phylogenetic analyses based on partial gene fragments of the translation elongation factor 1-alpha (tef1), beta-tubulin (tub2), calmodulin (cmdA), RNA polymerase largest subunit (rpb1) and RNA polymerase II second largest subunit (rpb2). Based on these results three new species were delimited in the FFSC. Two of these phylospecies clustered within the African clade, and one in the American clade. Epitypes were also designated for six previously described FFSC species including F. proliferatum and F. verticillioides, and a neotype designated for F. subglutinans. Furthermore, both F. acutatum and F. ophioides, which were previously invalidly published, are validated.


Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 463
Author(s):  
Amal Rabaaoui ◽  
Chiara Dall’Asta ◽  
Laura Righetti ◽  
Antonia Susca ◽  
Antonio Logrieco ◽  
...  

In 2017–2018, extensive symptoms of sudden decline and fruit rot were observed on date palms in southern Tunisia. Samples of diseased plants were randomly collected in six localities. Based on morphological identification, Fusarium was the most frequent fungal genus detected. A sequencing of translation elongation factor, calmodulin, and second largest subunit of RNA polymerase II genes was used to identify 63 representative Fusarium strains at species level and investigate their phylogenetic relationships. The main species detected was Fusarium proliferatum, and at a much lesser extent, Fusarium brachygibbosum, Fusarium caatingaense, Fusarium clavum, Fusarium incarnatum, and Fusarium solani. Pathogenicity on the Deglet Nour variety plantlets and the capability to produce mycotoxins were also assessed. All Fusarium species were pathogenic complying Koch’s postulates. Fusarium proliferatum strains produced mainly fumonisins (FBs), beauvericin (BEA), and, to a lesser extent, enniatins (ENNs) and moniliformin (MON). All F. brachygibbosum strains produced low levels of BEA, diacetoxyscirpenol, and neosolaniol; two strains produced also T-2 toxin, and a single strain produced HT-2 toxin. Fusarium caatingaense, F. clavum, F. incarnatum produced only BEA. Fusarium solani strains produced MON, BEA, and ENNs. This work reports for the first time a comprehensive multidisciplinary study of Fusarium species on date palms, concerning both phytopathological and food safety issues.


Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1059-1070
Author(s):  
Susie C Howard ◽  
Arelis Hester ◽  
Paul K Herman

Abstract The Ras signaling pathway in Saccharomyces cerevisiae controls cell growth via the cAMP-dependent protein kinase, PKA. Recent work has indicated that these effects on growth are due, in part, to the regulation of activities associated with the C-terminal domain (CTD) of the largest subunit of RNA polymerase II. However, the precise target of these Ras effects has remained unknown. This study suggests that Ras/PKA activity regulates the elongation step of the RNA polymerase II transcription process. Several lines of evidence indicate that Spt5p in the Spt4p/Spt5p elongation factor is the likely target of this control. First, the growth of spt4 and spt5 mutants was found to be very sensitive to changes in Ras/PKA signaling activity. Second, mutants with elevated levels of Ras activity shared a number of specific phenotypes with spt5 mutants and vice versa. Finally, Spt5p was efficiently phosphorylated by PKA in vitro. Altogether, the data suggest that the Ras/PKA pathway might be directly targeting a component of the elongating polymerase complex and that this regulation is important for the normal control of yeast cell growth. These data point out the interesting possibility that signal transduction pathways might directly influence the elongation step of RNA polymerase II transcription.


1990 ◽  
Vol 10 (10) ◽  
pp. 5433-5441
Author(s):  
B Y Ahn ◽  
P D Gershon ◽  
E V Jones ◽  
B Moss

Eucaryotic transcription factors that stimulate RNA polymerase II by increasing the efficiency of elongation of specifically or randomly initiated RNA chains have been isolated and characterized. We have identified a 30-kilodalton (kDa) vaccinia virus-encoded protein with apparent homology to SII, a 34-kDa mammalian transcriptional elongation factor. In addition to amino acid sequence similarities, both proteins contain C-terminal putative zinc finger domains. Identification of the gene, rpo30, encoding the vaccinia virus protein was achieved by using antibody to the purified viral RNA polymerase for immunoprecipitation of the in vitro translation products of in vivo-synthesized early mRNA selected by hybridization to cloned DNA fragments of the viral genome. Western immunoblot analysis using antiserum made to the vaccinia rpo30 protein expressed in bacteria indicated that the 30-kDa protein remains associated with highly purified viral RNA polymerase. Thus, the vaccinia virus protein, unlike its eucaryotic homolog, is an integral RNA polymerase subunit rather than a readily separable transcription factor. Further studies showed that the expression of rpo30 is regulated by dual early and later promoters.


2021 ◽  
Vol 35 (3-4) ◽  
pp. 273-285
Author(s):  
Bin Zheng ◽  
Yuki Aoi ◽  
Avani P. Shah ◽  
Marta Iwanaszko ◽  
Siddhartha Das ◽  
...  

Science ◽  
1996 ◽  
Vol 271 (5257) ◽  
pp. 1873-1876 ◽  
Author(s):  
A. Shilatifard ◽  
W. S. Lane ◽  
K. W. Jackson ◽  
R. C. Conaway ◽  
J. W. Conaway

2009 ◽  
Vol 425 (2) ◽  
pp. 373-380 ◽  
Author(s):  
Sabine Wenzel ◽  
Berta M. Martins ◽  
Paul Rösch ◽  
Birgitta M. Wöhrl

The eukaryotic transcription elongation factor DSIF [DRB (5,6-dichloro-1-β-D-ribofuranosylbenzimidazole) sensitivity-inducing factor] is composed of two subunits, hSpt4 and hSpt5, which are homologous to the yeast factors Spt4 and Spt5. DSIF is involved in regulating the processivity of RNA polymerase II and plays an essential role in transcriptional activation of eukaryotes. At several eukaryotic promoters, DSIF, together with NELF (negative elongation factor), leads to promoter-proximal pausing of RNA polymerase II. In the present paper we describe the crystal structure of hSpt4 in complex with the dimerization region of hSpt5 (amino acids 176–273) at a resolution of 1.55 Å (1 Å=0.1 nm). The heterodimer shows high structural similarity to its homologue from Saccharomyces cerevisiae. Furthermore, hSpt5-NGN is structurally similar to the NTD (N-terminal domain) of the bacterial transcription factor NusG. A homologue for hSpt4 has not yet been found in bacteria. However, the archaeal transcription factor RpoE” appears to be distantly related. Although a comparison of the NusG-NTD of Escherichia coli with hSpt5 revealed a similarity of the three-dimensional structures, interaction of E. coli NusG-NTD with hSpt4 could not be observed by NMR titration experiments. A conserved glutamate residue, which was shown to be crucial for dimerization in yeast, is also involved in the human heterodimer, but is substituted for a glutamine residue in Escherichia coli NusG. However, exchanging the glutamine for glutamate proved not to be sufficient to induce hSpt4 binding.


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