Xanthomonas translucens pv. undulosa identified on common weedy grasses in naturally infected wheat fields in Minnesota

2020 ◽  
Author(s):  
Kristi Ellen Ledman ◽  
Rebecca D. Curland ◽  
Carol Ishimaru ◽  
Ruth Dill-Macky
Keyword(s):  
Housekeeping Genes ◽  
Grass Species ◽  
Bacterial Leaf Streak ◽  
In Planta ◽  
Smooth Brome ◽  
The Past ◽  
Perennial Weeds ◽  
Xanthomonas Translucens ◽  
Grass Hosts ◽  
Sequence Types

Bacterial leaf streak (BLS) of wheat, caused by Xanthomonas translucens pv. undulosa, has been a notable disease in Minnesota wheat fields over the past decade. Potential sources of the pathogen include infested seed and crop debris. Perennial weeds are also considered a possible inoculum source, but no surveys have been conducted to evaluate which X. translucens pathovars are present on weedy grasses that are common in Minnesota wheat fields. Multilocus sequence analysis (MLSA) of four housekeeping genes (rpoD, dnaK, fyuA, and gyrB) was used to identify 77 strains isolated from six weedy grass species, wheat, and barley in and around naturally infected wheat fields in Minnesota. The MLSA phylogeny identified all strains originating from weedy grass species, except smooth brome, as X. translucens pv. undulosa, whereas strains isolated from smooth brome were determined to be X. translucens pv. cerealis. In planta character states corroborated these identifications on a subset of 41 strains, as all strains from weedy grasses caused water-soaking on wheat and barley in greenhouse assays. Multilocus sequence typing (MLST) was used to evaluate genetic diversity and revealed that sequence types of X. translucens pv. undulosa originating from weedy grass hosts are similar to those found on wheat. This study identifies both annual and perennial poaceous weeds common in Minnesota that can harbor X. translucens pv. undulosa and expands our understanding of the diversity of the pathogen population.

scholarly journals Localized Genetic and Phenotypic Diversity of Xanthomonas translucens Associated With Bacterial Leaf Streak on Wheat and Barley in Minnesota

2020 ◽  
Vol 110 (2) ◽  
pp. 257-266
Author(s):  
Rebecca D. Curland ◽  
Liangliang Gao ◽  
Cory D. Hirsch ◽  
Carol A. Ishimaru
Keyword(s):  
Phenotypic Diversity ◽  
Housekeeping Genes ◽  
Field Trials ◽  
Bacterial Leaf Streak ◽  
Upper Midwest ◽  
Sequence Alignments ◽  
Xanthomonas Translucens ◽  
Population Structures ◽  
Pathogenic Diversity ◽  
Sequence Types

Bacterial leaf streak (BLS) of wheat and barley has been a disease of increasing concern in the Upper Midwest over the past decade. In this study, intra- and interfield genetic and pathogenic diversity of bacteria causing BLS in Minnesota was evaluated. In 2015, 89 strains were isolated from 100 leaf samples collected from two wheat and two barley fields naturally infected with BLS. Virulence assays and multilocus sequence alignments of four housekeeping genes supported pathovar identifications. All wheat strains were pathogenic on wheat and barley and belonged to the same lineage as the Xanthomonas translucens pv. undulosa-type strain. All barley strains were pathogenic on barley but not on wheat. Three lineages of barley strains were detected. The frequency and number of sequence types of each pathovar varied within and between fields. A significant population variance was detected between populations of X. translucens pv. undulosa collected from different wheat fields. Population stratification of X. translucens pv. translucens was not detected. Significant differences in virulence were detected among three dominant sequence types of X. translucens pv. undulosa but not those of X. translucens pv. translucens. Field trials with wheat and barley plants inoculated with strains of known sequence type and virulence did not detect significant race structures within either pathovar. Knowledge of virulence, sequence types, and population structures of X. translucens on wheat and barley can support studies on plant–bacterial interactions and breeding for BLS disease resistance.

scholarly journals First report of bacterial leaf streak caused by Xanthomonas translucens pv. undulosa on cultivated wild rice (Zizania palustris) in Minnesota

Plant Disease ◽  
2021 ◽  
Author(s):  
Rebecca D. Curland ◽  
Kathryn R Hallada ◽  
Kristi E Ledman ◽  
Ruth Dill-Macky
Keyword(s):  
Host Range ◽  
Wild Rice ◽  
Host Response ◽  
Management Practices ◽  
Spring Barley ◽  
Post Inoculation ◽  
Bacterial Leaf Streak ◽  
Smooth Brome ◽  
Zizania Palustris ◽  
Xanthomonas Translucens

Known by the indigenous peoples of the Great Lakes region of North America as Manoomin, wild rice (Zizania palustris) is a native aquatic grass that is honored and central to Anishinaabe culture. Cultivated wild rice, the domesticated form of this cereal bred primarily for resistance to shattering, is grown commercially in paddies. In this study we examined four isolates (CIX303, CIX306, Xt-8, and Xt-22) of Xanthomonas translucens, the causative agent of bacterial leaf streak (BLS) on cereals and weedy grasses, in molecular and host range studies to confirm the pathovar identity of strains associated with cultivated wild rice. Two of the strains examined (CIX303 and CIX306), were isolated from cultivated wild rice in 2016 as part of a survey of the pathogen in Minnesota (Ledman 2019). Xt-8 and Xt-22 are historical strains of X. translucens isolated from symptomatic wild rice leaves collected in Minnesota in the late 1970s that were reported at the time to be X. campestris pv. cerealis (Bowden and Percich 1982). A host range assay was repeated twice in the greenhouse, where two leaves of six seedlings each of hard red spring wheat (cv. RB07), spring barley (cv. Quest), spring rye (cv. Prolific), oat (cv. Ogle), quackgrass, smooth brome grass and cultivated wild rice (cv. Itasca Cycle-12) were inoculated via leaf infiltration (Curland et al. 2020). X. translucens pv. cerealis LMG 679PT, X. translucens pv. secalis LMG 883PT, X. translucens pv. translucens LMG 876T, and X. translucens pv. undulosa LMG 892PT were included as reference strains. Host response profiles were determined for each strain by recording character states five days post inoculation. Water-soaking and necrosis were considered pathogenic reactions, whereas chlorosis was not. Three pathotype strains, LMG 679PT, LMG 876T, and LMG 892PT, caused water-soaking in cultivated wild rice, whereas LMG 883PT caused chlorosis. All four strains from cultivated wild rice produced water-soaking on wheat, barley, quackgrass, and cultivated wild rice, chlorosis or water-soaking on rye, chlorosis on oat, and a reddish water-soaking on smooth brome. The character states generated by these four isolates were identical only to the host response profile for LMG 892PT. LMG 679PT differed, causing chlorosis on wheat, no symptoms on quackgrass, and water-soaking on smooth brome. A 2645 bp concatenation of housekeeping genes (rpoD, dnaK, fyuA, gyrB) was used to perform a Bayesian analysis (GenBank accessions MW528365-MW528384) (Curland et al. 2018, Curland et al. 2020, Young et al. 2008). Subsequent phylogenies grouped all four strains from cultivated wild rice with LMG 892PT and LMG 883PT. A pairwise comparison revealed 100% identity between Xt-22 and LMG 892PT. The percentage identity of CIX303, CIX308, and Xt-8 to LMG 892PT was 99.96, 99.96, and 99.92, respectively. In contrast, when compared to LMG 679PT, the four strains from cultivated wild rice had a percent identity between 97.43 and 97.50. Based on host range studies combined with MLSA, we identified recent and historical isolates from Z. palustris as X. translucens pv. undulosa. Pathovar identity of strains causing BLS on cultivated wild rice in Minnesota is crucial when screening breeding materials for disease resistance. Furthermore, given that X. translucens pv. undulosa has been prevalent on wheat in Minnesota (Curland et al. 2018), expanding knowledge of its host range to include cultivated wild rice may inform disease management practices for both crops. References: Bowden, R., and Percich, J. 1982. Phytopath. 73:640-645. Curland, R., et al. 2018. Phytopath. 108:443–453. Curland, R., et al. 2020. Phytopath. 110:257–266. Ledman, K. 2019. M.S. Thesis, Univ. of Minnesota, St. P. Paul, USA. Young, J., et al. 2008. Syst. Appl. Microbiol. 31:366–377.

scholarly journals Multi-locus sequence types of Mycoplasma bovis isolated from Ontario, Canada in the past three decades have a temporal distribution

2017 ◽  
Vol 30 (1) ◽  
pp. 130-135 ◽  
Author(s):  
Patricia Bell-Rogers ◽  
Lois Parker ◽  
Hugh Y. Cai
Keyword(s):  
Sequence Analysis ◽  
Molecular Typing ◽  
Sequence Variation ◽  
Sequence Data ◽  
Temporal Distribution ◽  
Housekeeping Genes ◽  
Multi Locus Sequence Typing ◽  
Mycoplasma Bovis ◽  
The Past ◽  
Sequence Types

A total of 217 Mycoplasma bovis isolates cultured from clinical cases in Ontario, Canada, over the past 30 y were selected to be characterized by a multi-locus sequence typing (MLST) method. Eleven housekeeping genes were evaluated for suitability for MLST; 2 loci that had been used in prior MLST schemes, dnaN and metS, along with hsp70 were chosen for further sequence analysis. The remaining loci— adk, efp, gmk, gyrB, polC, rpoB, tpiA, and uvrC genes—were not used because they had little to no sequence variation. The sequence data from the chosen loci ( dnaN, hsp70, metS) generated 28 sequence types (STs), with the 3 loci having 15, 5, and 7 alleles, respectively. These molecular typing results revealed that the STs had a temporal distribution; over the course of 3 decades, some STs disappeared and new STs appeared. Recent isolates had a greater variety of STs, which may indicate that new strains are emerging more rapidly now than in the past.

scholarly journals Genetic Diversity and Virulence of Wheat and Barley Strains of Xanthomonas translucens from the Upper Midwestern United States

2018 ◽  
Vol 108 (4) ◽  
pp. 443-453 ◽  
Author(s):  
Rebecca D. Curland ◽  
Liangliang Gao ◽  
Carolee T. Bull ◽  
Boris A. Vinatzer ◽  
Ruth Dill-Macky ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Spanning Trees ◽  
Effective Means ◽  
Resistance Breeding ◽  
Housekeeping Genes ◽  
In Planta ◽  
Midwestern United States ◽  
Intermediate Wheatgrass ◽  
Xanthomonas Translucens

Bacterial leaf streak (BLS) of wheat and barley, caused by Xanthomonas translucens pv. undulosa and X. translucens pv. translucens, has been of growing concern in small grains production in the Upper Midwestern United States. To optimize disease resistance breeding, a greater awareness is needed of the pathovars and genetic diversity within the pathogens causing BLS in the region. Multilocus sequencing typing (MLST) and analysis (MLSA) of four common housekeeping genes (rpoD, dnaK, fyuA, and gyrB) was used to evaluate the genetic diversity of 82 strains of X. translucens isolated between 2006 and 2013 from wheat, barley, rye, and intermediate wheatgrass. In addition, in planta disease assays were conducted on 75 strains to measure relative virulence in wheat and barley. All strains were determined by MLSA to be related to X. translucens pv. undulosa and X. translucens pv. translucens. Clustering of strains based on Bayesian, network, and minimum spanning trees correlated with relative virulence levels in inoculated wheat and barley. Thus, phylogeny based on rpoD, dnaK, fyuA, and gyrB correlated with host of isolation and was an effective means for predicting virulence of strains belonging to X. translucens pv. translucens and X. translucens pv. undulosa.

scholarly journals Grass Hosts Harbor More Diverse Isolates of Puccinia striiformis Than Cereal Crops

2016 ◽  
Vol 106 (4) ◽  
pp. 362-371 ◽  
Author(s):  
P. Cheng ◽  
X. M. Chen ◽  
D. R. See
Keyword(s):  
Ssr Markers ◽  
Stripe Rust ◽  
Simple Sequence Repeat ◽  
Puccinia Striiformis ◽  
The United States ◽  
Grass Species ◽  
Cereal Crops ◽  
Sequence Repeat ◽  
Grass Hosts ◽  
Simple Sequence

Puccinia striiformis causes stripe rust on cereal crops and many grass species. However, it is not clear whether the stripe rust populations on grasses are able to infect cereal crops and how closely they are related to each other. In this study, 103 isolates collected from wheat, barley, triticale, rye, and grasses in the United States were characterized by virulence tests and simple sequence repeat (SSR) markers. Of 69 pathotypes identified, 41 were virulent on some differentials of wheat only, 10 were virulent on some differentials of barley only, and 18 were virulent on some differentials of both wheat and barley. These pathotypes were clustered into three groups: group one containing isolates from wheat, triticale, rye, and grasses; group two isolates were from barley and grasses; and group three isolates were from grasses and wheat. SSR markers identified 44 multilocus genotypes (MLGs) and clustered them into three major molecular groups (MG) with MLGs in MG3 further classified into three subgroups. Isolates from cereal crops were present in one or more of the major or subgroups, but not all, whereas grass isolates were present in all of the major and subgroups. The results indicate that grasses harbor more diverse isolates of P. striiformis than the cereals.

Nonencapsulated or nontypeableHaemophilus influenzaeare more likely than their encapsulated or serotypeable counterparts to have mutations in their fucose operon

2011 ◽  
Vol 57 (12) ◽  
pp. 982-986 ◽  
Author(s):  
Michelle L. Shuel ◽  
Kathleen E. Karlowsky ◽  
Dennis K.S. Law ◽  
Raymond S.W. Tsang
Keyword(s):  
Nucleotide Sequence ◽  
Haemophilus Influenzae ◽  
Dna Sequencing ◽  
Multilocus Sequence Typing ◽  
Population Biology ◽  
Housekeeping Genes ◽  
Sequence Variations ◽  
Sequence Types ◽  
Complete Deletion

Population biology of Haemophilus influenzae can be studied by multilocus sequence typing (MLST), and isolates are assigned sequence types (STs) based on nucleotide sequence variations in seven housekeeping genes, including fucK. However, the ST cannot be assigned if one of the housekeeping genes is absent or cannot be detected by the current protocol. Occasionally, strains of H. influenzae have been reported to lack the fucK gene. In this study, we examined the prevalence of this mutation among our collection of H. influenzae isolates. Of the 704 isolates studied, including 282 encapsulated and 422 nonencapsulated isolates, nine were not typeable by MLST owing to failure to detect the fucK gene. All nine fucK-negative isolates were nonencapsulated and belonged to various biotypes. DNA sequencing of the fucose operon region confirmed complete deletion of genes in the operon in seven of the nine isolates, while in the remaining two isolates, some of the genes were found intact or in parts. The significance of these findings is discussed.

The taxonomic position of C3 and C4 Alloteropsis semialata (Poaceae) in southern Africa

Bothalia ◽  
1983 ◽  
Vol 14 (2) ◽  
pp. 205-213 ◽  
Author(s):  
G. E. Gibbs Russell
Keyword(s):  
Southern Africa ◽  
Leaf Blade ◽  
Morphological Characters ◽  
Taxonomic Position ◽  
Grass Species ◽  
The Past ◽  
Photosynthetic Pathways ◽  
Voucher Specimens

Alloteropsis semialata (R. Br.) Hitchc. sensu Chippindall (1955) and Clayton (in press) is the only known grass species in which elements with both non-Kranz and Kranz leaf blade anatomy, and therefore with C3 and C4 photosynthetic pathways are included. In the past, two taxa had been recognized, but the characters used to separate them were found to be unreliable, so they were united. However, study of voucher specimens for anatomical and physiological work has shown that C3 and C4 taxa may be separated on the basis of morphological characters that differ from those considered in the past. Therefore, two taxa are again recognized, this time at the rank of subspecies, and the name  Alloteropsis semialata subsp. eckloniana (Nees) Gibbs Russell  stat. nov. is published.

scholarly journals Molecular Typing Reveals High Genetic Diversity of Xanthomonas translucens Strains Infecting Small-Grain Cereals in Iran

2019 ◽  
Vol 85 (20) ◽  
Author(s):  
Moein Khojasteh ◽  
S. Mohsen Taghavi ◽  
Pejman Khodaygan ◽  
Habiballah Hamzehzarghani ◽  
Gongyou Chen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Global Scale ◽  
Population Diversity ◽  
Bacterial Leaf Streak ◽  
High Genetic Diversity ◽  
Center Of Origin ◽  
Content Type ◽  
Xanthomonas Translucens ◽  
Insight Into

ABSTRACT This study provides a phylogeographic insight into the population diversity of Xanthomonas translucens strains causing bacterial leaf streak disease of small-grain cereals in Iran. Among the 65 bacterial strains isolated from wheat, barley, and gramineous weeds in eight Iranian provinces, multilocus sequence analysis and typing (MLSA and MLST) of four housekeeping genes (dnaK, fyuA, gyrB, and rpoD), identified 57 strains as X. translucens pv. undulosa, while eight strains were identified as X. translucens pv. translucens. Although the pathogenicity patterns on oat and ryegrass weed species varied among the strains, all X. translucens pv. undulosa strains were pathogenic on barley, Harding’s grass, rye (except for XtKm35) and wheat, and all X. translucens pv. translucens strains were pathogenic on barley and Harding’s grass, while none of the latter group was pathogenic on rye or wheat (except for XtKm18). MLST using the 65 strains isolated in Iran, as well as the sequences of the four genes from 112 strains of worldwide origin retrieved from the GenBank database, revealed higher genetic diversity (i.e., haplotype frequency, haplotype diversity, and percentage of polymorphic sites) among the Iranian population of X. translucens than among the North American strains of the pathogen. High genetic diversity of the BLS pathogen in Iran was in congruence with the fact that the Iranian Plateau is considered the center of origin of cultivated wheat. However, further studies using larger collections of strains are warranted to precisely elucidate the global population diversity and center of origin of the pathogen. IMPORTANCE Bacterial leaf streak (BLS) of small-grain cereals (i.e., wheat and barley) is one of the economically important diseases of gramineous crops worldwide. The disease occurs in many countries across the globe, with particular importance in regions characterized by high levels of precipitation. Two genetically distinct xanthomonads—namely, Xanthomonas translucens pv. undulosa and X. translucens pv. translucens—have been reported to cause BLS disease on small-grain cereals. As seed-borne pathogens, the causal agents are included in the A2 list of quarantine pathogens by the European and Mediterranean Plant Protection Organization (EPPO). Despite its global distribution and high economic importance, the population structure, genetic diversity, and phylogeography of X. translucens remain undetermined. This study, using MLSA and MLST, provides a global-scale phylogeography of X. translucens strains infecting small-grain cereals. Based on the diversity parameters, neutrality indices, and population structure, we observe higher genetic diversity of the BLS pathogen in Iran, which is geographically close to the center of origin of common wheat, than has so far been observed in other areas of the world, including North America. The results obtained in this study provide a novel insight into the genetic diversity and population structure of the BLS pathogen of small-grain cereals on a global scale.

scholarly journals Genetic diversity in Italian Lactobacillus sanfranciscensis strains assessed by multilocus sequence typing and pulsed-field gel electrophoresis analyses

Microbiology ◽  
2010 ◽  
Vol 156 (7) ◽  
pp. 2035-2045 ◽  
Author(s):  
Claudia Picozzi ◽  
Gaia Bonacina ◽  
Ileana Vigentini ◽  
Roberto Foschino
Keyword(s):  
Multilocus Sequence Typing ◽  
Geographical Area ◽  
Housekeeping Genes ◽  
Processing Conditions ◽  
Clonal Population ◽  
Factors Affecting ◽  
Lactobacillus Sanfranciscensis ◽  
Mlst Scheme ◽  
Sequence Types

Lactobacillus sanfranciscensis is a lactic acid bacterium that characterizes the sourdough environment. The genetic differences of 24 strains isolated in different years from sourdoughs, mostly collected in Italy, were examined and compared by PFGE and multilocus sequence typing (MLST). The MLST scheme, based on the analysis of six housekeeping genes (gdh, gyrA, mapA, nox, pgmA and pta) was developed for this study. PFGE with the restriction enzyme ApaI proved to have higher discriminatory power, since it revealed 22 different pulsotypes, while 19 sequence types were recognized through MLST analysis. Notably, restriction profiles generated from three isolates collected from the same firm but in three consecutive years clustered in a single pulsotype and showed the same sequence type, emphasizing the fact that the main factors affecting the dominance of a strain are correlated with processing conditions and the manufacturing environment rather than the geographical area. All results indicated a limited recombination among genes and the presence of a clonal population in L. sanfranciscensis. The MLST scheme proposed in this work can be considered a useful tool for characterization of isolates and for in-depth examination of the strain diversity and evolution of this species.

Occurrence and distribution of native and introduced C4 grasses in Tasmania

2002 ◽  
Vol 50 (6) ◽  
pp. 667 ◽  
Author(s):  
Mark J. Hovenden ◽  
Dennis I. Morris
Keyword(s):  
Urban Areas ◽  
General Distribution ◽  
Grass Species ◽  
Past Century ◽  
C4 Grasses ◽  
Photosynthetic Pathway ◽  
Limited Distribution ◽  
The Past ◽  
C4 Species ◽  
C4 Grass

Of the 137 species of grass considered native to Tasmania, only eight use the C4 photosynthetic pathway. There are also approximately 137 grass species considered as introduced to Tasmania and 21% of these are C4. In total, there are 41 species from 20 genera of C4 grass recorded from Tasmania. Many of the introduced C4 species have a very limited distribution, however, and are generally confined to urban areas and along roadsides. Overall, Tasmania has fewer C4 grasses than would be expected from climate alone and few of the C4 grass species are widely distributed or abundant. However, the proportion of grasses recorded from Tasmania that use the C4 pathway has been increasing for the past century and is still increasing. General distribution and habitat notes are provided for all C4 grasses known to be native or naturalised in Tasmania.

Sign in / Sign up

Export Citation Format

Share Document