scholarly journals First Report of Atypical Xanthomonas euvesicatoria Strains Causing Bacterial Spot of Tomato in Nigeria

Plant Disease ◽  
2015 ◽  
Vol 99 (3) ◽  
pp. 415-415 ◽  
Author(s):  
M. O. Jibrin ◽  
S. Timilsina ◽  
N. Potnis ◽  
G. V. Minsavage ◽  
K. C. Shenge ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
Sequence Divergence ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Bacterial Spot ◽  
Gene Sequences ◽  
Leaf Spots ◽  
Brown Leaf ◽  
Xanthomonas Species ◽  
Pathogenicity Tests

Bacterial spot (BS) is an important disease of tomato in Nigeria (2). Although a xanthomonad was isolated from tomato in Nigeria and characterized using phenotypic and pathogenicity tests, the bacterium was not characterized genetically to confirm the species. To determine the species associated with BS, leaves were collected in fields in northwestern Nigeria from tomato plants showing typical BS symptoms, which consisted of dark, irregular-shaped brown leaf spots that coalesced, resulting in a blighted appearance. Isolations from individual lesions were made on nutrient agar (NA). Yellow, mucoid colonies typical of Xanthomonas were isolated from 14 lesions and all were determined to be amylolytic (3). To determine the races of these strains, bacterial suspensions of the tomato strains, derived from 24-h cultures grown on NA at 28°C, were adjusted to 108 CFU/ml and infiltrated into leaves of tomato and pepper differential genotypes (5). The tomato strains elicited hypersensitive reactions (HRs) on the four pepper differential lines and an HR on the tomato genotype FL 216, which contains the R gene Xv3, but elicited susceptible reactions on the tomato genotypes Hawaii 7998 and Bonny Best. These reactions are typical of X. perforans tomato race 3 strains (5). Multilocus sequence analysis (MLSA) of six housekeeping genes (fusA, lacF, gyrB, gltA, gapA, and lepA) was used to further analyze four representative strains (1) (GenBank Accession Nos. KJ938581 to KJ938584, KJ938588 to KJ938591, KJ938595 to KJ938598, KJ938602 to KJ938605, KJ938629 to KJ938632, and KJ938636 to KJ938639, respectively). A partial sequence of hrpB2 was also made since the four Xanthomonas species associated with BS can be differentiated based on sequence divergence of this gene (3) (KJ938609 to KJ938621 and KJ938628). The housekeeping gene sequences were aligned along with other Xanthomonas sequences imported from the National Center for Biotechnology Information (NCBI) database ( www.ncbi.nlm.nih.gov ) using the MUSCLE tool from MEGA software, 5.2.2. Maximum likelihood phylogenetic trees constructed for the six housekeeping gene sequences individually and in concatenation revealed that the strains grouped most closely with the X. euvesicatoria reference strain 85-10 but more distantly to X. perforans. The hrpB2 sequence, which is highly conserved for each Xanthomonas species pathogenic on tomato (4), was sequenced from the tomato strains. These sequences were identical to the hrpB2 sequence from X. perforans strains but different from X. euvesicatoria. Although BS is common in Nigeria, to our knowledge, this represents a unique group of X. euvesicatoria strains from tomato that are identical to X. perforans based on pathogenic reactions on tomato and pepper and hrpB2 sequence identity but are more closely related to X. euvesicatoria based on the six housekeeping gene sequences. References: (1) N. F. Almeida et al. Phytopathology 100:208, 2010. (2) E. U. Opara and F. J. Odibo. J. Mol. Genet. 1:35, 2009. (3) J. B. Jones et al. Syst. Appl. Microbiol. 27:755, 2004. (4) A. Obradovic et al. Eur. J. Plant Pathol. 88:736, 2004. (5) R. E. Stall et al. Annu. Rev. Phytopathol. 47:265, 2009.

scholarly journals First Report of Xanthomonas euvesicatoria Causing Bacterial Spot Disease in Pepper in Northwestern Nigeria

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1426-1426 ◽  
Author(s):  
M. O. Jibrin ◽  
S. Timilsina ◽  
N. Potnis ◽  
G. V. Minsavage ◽  
K. C. Shenge ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
Xanthomonas Campestris ◽  
Sequence Divergence ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Bacterial Spot ◽  
Gene Sequences ◽  
First Report ◽  
Xanthomonas Species ◽  
Pepper Leaves

Bacterial spot (BS) has been reported as an important disease on pepper in Nigeria (4). Xanthomonas campestris pv. vesicatoria was identified as the causal agent using phenotypic and pathogenicity tests; however, X. campestris pv. vesicatoria is a synonym for two genetically distinct groups that have been elevated to the species X. euvesicatoria and X. vesicatoria (2). Furthermore, the latter two species and X. gardneri cause similar diseases on pepper (2). In order to determine the species associated with BS on pepper, leaves with irregular, dark brown lesions were collected from pepper plants in fields from northwestern Nigeria, and isolations were made on nutrient agar (NA). Yellow, mucoid colonies typical of Xanthomonas were isolated. Six strains isolated from pepper were determined to be non-amylolytic. For race determinations, bacterial suspensions of the pepper strains, derived from 24-h cultures grown on NA at 28°C, were adjusted to 108 CFU/ml and infiltrated into leaves of tomato and pepper differential genotypes (5). The six pepper strains elicited HRs on the tomato differential genotypes. The strains produced a susceptible reaction on all pepper differentials and were designated as pepper race 6 (5). Multilocus sequence analysis (MLSA) using six housekeeping genes (fusA, lacF, gyrB, gltA, gapA, and lepA) was used to further analyze the strains (1) (GenBank Accession Nos. KJ938585 to KJ938587, KJ938592 to KJ938594, KJ938599 to KJ938601, KJ938606 to KJ938608, KJ938633 to KJ938635, and KJ938640 to KJ938642). A partial sequence of hrpB2 was also sequenced since the four Xanthomonas species associated with BS can be differentiated based on sequence divergence (3) (KJ938622 to KJ938627). The housekeeping gene sequences were aligned along with other Xanthomonas sequences imported from the NCBI database using muscle tool from MEGA software, 5.2.2. Maximum likelihood phylogenetic trees constructed for the six housekeeping gene sequences individually and in concatenation revealed that the Nigerian pepper strains were identical to the X. euvesicatoria reference strain 85-10. Although BS is common in Nigeria, to our knowledge, this represents the first report for this pepper pathogen in Nigeria. References: (1) N. F. Almeida et al. Phytopathology 100:208, 2010. (3) J. B. Jones et al. System Appl. Microbiol. 27:755, 2004. (4) A. Obradovic et al. Eur. J. Plant Pathol. 88:736, 2004. (2) E. U. Opara and F. J. Odibo. J. Mol. Gen. 1:35, 2009. (5) R. E. Stall et al. Ann. Rev. Phytopathol. 47:265, 2009.

scholarly journals A New Subclade of Leptosphaeria biglobosa Identified from Brassica rapa

2019 ◽  
Vol 20 (7) ◽  
pp. 1668 ◽  
Author(s):  
Zhongwei Zou ◽  
Xuehua Zhang ◽  
Paula Parks ◽  
Lindsey du Toit ◽  
Angela Van de Wouw ◽  
...  
Keyword(s):  
Brassica Rapa ◽  
Phylogenetic Trees ◽  
Single Gene ◽  
Leptosphaeria Maculans ◽  
Stem Canker ◽  
Willamette Valley ◽  
Gene Sequences ◽  
Distance Analysis ◽  
Pathogenicity Tests ◽  
Leptosphaeria Biglobosa

Blackleg (Phoma stem canker) of crucifers is a globally important disease caused by the ascomycete species complex comprising of Leptosphaeria maculans and Leptosphaeria biglobosa. Six blackleg isolates recovered from Brassica rapa cv. Mizspoona in the Willamette Valley of Oregon were characterized as L. biglobosa based on standard pathogenicity tests and molecular phylogenetic analysis. These isolates were compared to 88 characterized L. biglobosa isolates from western Canada, 22 isolates from Australia, and 6 L. maculans isolates from Idaho, USA using maximum parsimony and distance analysis of phylogenetic trees generated from the ITS rDNA (internal transcribed spacer rDNA) sequence, and the actin and β-tubulin gene sequences. The L. biglobosa isolates derived from B. rapa collected in Oregon formed a separate subclade based on concatenated gene sequences or a single gene sequence, regardless of the analyses. Pathogenicity tests showed that these isolates failed to infect either resistant or susceptible B. napus cultivars, but caused severe symptoms on three B. rapa cultivars (Accession number: UM1113, UM1112, and UM1161), a B. oleracea var. capitata (cabbage) cultivar (Copenhagen Market), and two B. juncea cultivars (CBM, a common brown Mustard, and Forge). These findings demonstrated that the L. biglobosa isolates derived from a B. rapa crop in Oregon were genetically distinct from existing species of L. biglobosa, and constitute a new subclade, herein proposed as L. biglobosa ‘americensis’.

CONDITIONS FOR SYMPTOMATOLOGICAL DIFFERENTIATION OF BACTERIAL CANKER, SPOT, AND SPECK ON TOMATO SEEDLINGS

1966 ◽  
Vol 46 (5) ◽  
pp. 525-530 ◽  
Author(s):  
P. K. Basu
Keyword(s):  
Bacterial Canker ◽  
Bacterial Spot ◽  
Inoculum Concentration ◽  
Tomato Seedlings ◽  
Leaf Spots ◽  
Greenish Yellow ◽  
Brown Leaf ◽  
High Incidence ◽  
Bacterial Spot Disease ◽  
Xanthomonas Vesicatoria

Bacterial canker, spot, and speck of tomatoes (Lycopersicon esculentum Mill.) caused by Corynebacterium michiganense (E.F.S.) Jensen, Xanthomonas vesicatoria (Doidge) Dows., and Pseudomonas tomato (Okabe) Burk., respectively, were symptomatologically differentiated on 2- to 3-week-old spray-inoculated seedlings only under conditions of 87–97% relative humidity and 23–28 °C temperature. The numerical threshold of infection of both C. michiganense and P. tomato was 1 × 106 cells/ml and that of X. vesicatoria was 1 × 103 cells/ml. Preinoculation host injury and an inoculum concentration of 1 × 108 cells/ml were most favorable for high incidence of the diseases.Characteristic symptoms incited by the canker organism were (1) small whitish pimple-like spots developing into raised blister-like lesions on the lamina, (2) elongated swellings on veins, and (3) cankers on the hypocotyl. The distinctive symptoms of the bacterial spot disease were (1) small greenish-yellow to brown leaf spots, (2) large yellow blotches becoming necrotic and producing a severe blight effect on leaves, and (3) light-brown streaks on the hypocotyl. The distinguishing symptoms of the speck disease were discrete dark-brown spots and occasional marginal necrotic areas on leaves and cotyledons. On cotyledons, both C. michiganense and X. vesicatoria produced identical minute whitish flaky spots often with greenish centers. Sometimes these spots coalesced and resulted in wrinkling of the surface of the cotyledon.

scholarly journals First Report of Infection of Kiwifruit by Pestalotiopsis sp. in Turkey

Plant Disease ◽  
2001 ◽  
Vol 85 (9) ◽  
pp. 1028-1028 ◽  
Author(s):  
A. Karakaya
Keyword(s):  
Spore Suspension ◽  
Actinidia Deliciosa ◽  
High Humidity ◽  
Disease Symptoms ◽  
First Report ◽  
Leaf Spots ◽  
Plastic Bags ◽  
Brown Leaf ◽  
Pathogenicity Tests

Circular to irregular brown leaf spots, 0.2 to 1.5 cm in diameter, were commonly observed on kiwifruit (Actinidia deliciosa) cv. Hayward plants in the Artvin-Arhavi region of northeastern Turkey. Leaf spots sometimes covered large portions of infected leaves, giving them a blighted appearance. Fruit symptoms consisted of brown, sunken, shriveled areas that were 0.5 to 3 cm in diameter. A fungus, later identified as a Pestalotiopsis sp. (1), was consistently isolated from diseased tissues. Pathogenicity tests were performed on 2-year-old kiwifruit plants and mature fruits at 18/22°C (day/night). A spore suspension (1 × 106 conidia per ml) was sprayed on leaves of 2-year-old kiwifruit plants. Agar pieces, 3 mm in diameter, from 10-day-old cultures also were applied to the leaves. Controls were treated with water and agar alone. Plants were covered with plastic bags for 3 days to ensure high humidity. After 2 weeks, disease symptoms were observed on inoculated leaves. Pestalotiopsis sp. was consistently isolated from these regions. Agar pieces from 10-day-old cultures were placed in small wounds made on the surfaces of mature, surface-disinfested fruits. Controls were treated with agar pieces alone. Softening of tissues next to the wound was observed 1 week after inoculation. Pestalotiopsis sp. was isolated from these areas. No symptoms were observed on noninoculated leaves or fruits. It was concluded that this disease is caused by Pestalotiopsis sp. This is the first report of its occurrence in Turkey. Reference: (1) T. R. Nag Raj. Coelomycetous anamorphs with appendage bearing conidia. Mycologue Publications, Ontario, Canada, 1993.

scholarly journals Leaf spots of calibrachoa caused by Nigrospora oryzae

2020 ◽  
Vol 26 (4) ◽  
pp. 591-597
Author(s):  
Nicolás Pablo Borrelli ◽  
Santiago Stancanelli ◽  
Mirta Leonor Papone ◽  
María Virginia Moreno ◽  
Sebastián Stenglein ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Buenos Aires ◽  
First Record ◽  
Fungal Isolate ◽  
Leaf Spot Disease ◽  
Leaf Spots ◽  
Brown Leaf ◽  
The World ◽  
Pathogenicity Tests ◽  
Nigrospora Oryzae

Abstract Calibrachoa hybrida (calibrachoa, million bells) is a flowering ornamental with increasing importance due to the existence of many successful cultivars for growing indoors in containers and planting in the garden and landscape. The outstanding characteristic is a profuse flowering and intense colour. In October 2019, a fungal isolate was obtained from basal calibrachoa leaves with irregular brown leaf spots, in plants cultivated in Buenos Aires, Argentina. The aim of the present study was to identify the cause of the disease in this ornamental genus, to expand knowledge about prevalent pathologies. The isolate was identified using morphological and molecular markers, and the pathogenicity tests were fulfilled. This paper reports that Nigrospora oryzae is pathogenic to calibrachoa, which seems to be the first record of this leaf spot disease in the world.

scholarly journals Population Structure of the Bacillus cereus Group as Determined by Sequence Analysis of Six Housekeeping Genes and the plcR Gene

2004 ◽  
Vol 72 (9) ◽  
pp. 5253-5261 ◽  
Author(s):  
Kwan Soo Ko ◽  
Jong-Wan Kim ◽  
Jong-Man Kim ◽  
Wonyong Kim ◽  
Sang-in Chung ◽  
...  
Keyword(s):  
Population Structure ◽  
Bacillus Cereus ◽  
Phylogenetic Trees ◽  
Gene Tree ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
The Other ◽  
Gene Trees ◽  
History Of ◽  
Definition Of

ABSTRACT The population structure of the Bacillus cereus group (52 strains of B. anthracis, B. cereus, and B. thuringiensis) was investigated by sequencing seven gene fragments (rpoB, gyrB, pycA, mdh, mbl, mutS, and plcR). Most of the strains were classifiable into two large subgroups in six housekeeping gene trees but not in the plcR tree. In addition, several consistent clusters were identified, which were unrelated to species distinction. Moreover, interrelationships among these clusters were incongruent in each gene tree. The incongruence length difference test and split decomposition analyses also showed incongruences between genes, suggesting horizontal gene transfer. The plcR gene was observed to have characteristics that differed from those of the other genes in terms of phylogenetic topology and pattern of sequence diversity. Thus, we suggest that the evolutionary history of the PlcR regulon differs from those of the other chromosomal genes and that recombination of the plcR gene may be frequent. The homogeneity of B. anthracis, which is depicted as an independent lineage in phylogenetic trees, is suggested to be of recent origin or to be due to the narrow taxonomic definition of species.

scholarly journals Assessment of common housekeeping genes as reference for gene expression studies using RT-qPCR in mouse choroid plexus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kim Hoa Ho ◽  
Annarita Patrizi
Keyword(s):  
Gene Expression ◽  
Choroid Plexus ◽  
Sensory Deprivation ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Experimental Conditions ◽  
Brain Repair ◽  
Expression Studies ◽  
Testing Algorithms ◽  
Gene Expression Studies

AbstractChoroid plexus (ChP), a vascularized secretory epithelium located in all brain ventricles, plays critical roles in development, homeostasis and brain repair. Reverse transcription quantitative real-time PCR (RT-qPCR) is a popular and useful technique for measuring gene expression changes and also widely used in ChP studies. However, the reliability of RT-qPCR data is strongly dependent on the choice of reference genes, which are supposed to be stable across all samples. In this study, we validated the expression of 12 well established housekeeping genes in ChP in 2 independent experimental paradigms by using popular stability testing algorithms: BestKeeper, DeltaCq, geNorm and NormFinder. Rer1 and Rpl13a were identified as the most stable genes throughout mouse ChP development, while Hprt1 and Rpl27 were the most stable genes across conditions in a mouse sensory deprivation experiment. In addition, Rpl13a, Rpl27 and Tbp were mutually among the top five most stable genes in both experiments. Normalisation of Ttr and Otx2 expression levels using different housekeeping gene combinations demonstrated the profound effect of reference gene choice on target gene expression. Our study emphasized the importance of validating and selecting stable housekeeping genes under specific experimental conditions.

scholarly journals Distribution and recombination of Wolbachia endosymbionts in Korean coleopteran insects

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Gilsang Jeong ◽  
Taeman Han ◽  
Haechul Park ◽  
Soyeon Park ◽  
Pureum Noh
Keyword(s):  
16S Rrna ◽  
Phylogenetic Trees ◽  
Surface Protein ◽  
Rrna Gene ◽  
Infection Frequency ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Endosymbiotic Bacteria ◽  
Molecular Machinery ◽  
Broad Scale

Abstract Background Wolbachia are among the most prevalent endosymbiotic bacteria and induce reproductive anomalies in various invertebrate taxa. The bacterium has huge impacts on host reproductive biology, immunity, evolution, and molecular machinery. However, broad-scale surveys of Wolbachia infections at the order scale, including the order Coleoptera, are limited. In this study, we investigated the Wolbachia infection frequency in 201 Coleopteran insects collected in Korea. Results A total of 26 species (12.8%) belonging to 11 families harbored Wolbachia. The phylogenetic trees of based on partial 16S rRNA gene sequences and partial Wolbachia surface protein (wsp) gene sequences were largely incongruent to that of their hosts. This result confirms that Wolbachia evolved independently from their hosts, Conclusion Phylogenetic trees suggest that complex horizontal gene transfer and recombination events occurred within and between divergent Wolbachia subgroups.

scholarly journals Molecular Phylogenetic Diversity and Biological Characterization of Diaporthe Species Associated with Leaf Spots of Camellia sinensis in Taiwan

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1434
Author(s):  
Hiran A. Ariyawansa ◽  
Ichen Tsai ◽  
Jian-Yuan Wang ◽  
Patchareeya Withee ◽  
Medsaii Tanjira ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Leaf Spot ◽  
Phylogenetic Trees ◽  
Fungal Infections ◽  
Elongation Factor ◽  
Fungal Species ◽  
Tea Leaves ◽  
Phenotypic Characters ◽  
Leaf Spots ◽  
Molecular Phylogenetic

Camellia sinensis is one of the major crops grown in Taiwan and has been widely cultivated around the island. Tea leaves are prone to various fungal infections, and leaf spot is considered one of the major diseases in Taiwan tea fields. As part of a survey on fungal species causing leaf spots on tea leaves in Taiwan, 19 fungal strains morphologically similar to the genus Diaporthe were collected. ITS (internal transcribed spacer), tef1-α (translation elongation factor 1-α), tub2 (beta-tubulin), and cal (calmodulin) gene regions were used to construct phylogenetic trees and determine the evolutionary relationships among the collected strains. In total, six Diaporthe species, including one new species, Diaporthe hsinchuensis, were identified as linked with leaf spot of C. sinensis in Taiwan based on both phenotypic characters and phylogeny. These species were further characterized in terms of their pathogenicity, temperature, and pH requirements under laboratory conditions. Diaporthe tulliensis, D. passiflorae, and D. perseae were isolated from C. sinensis for the first time. Furthermore, pathogenicity tests revealed that, with wound inoculation, only D. hongkongensis was pathogenic on tea leaves. This investigation delivers the first assessment of Diaporthe taxa related to leaf spots on tea in Taiwan.

Real-time RT-PCR analysis of housekeeping genes in human skeletal muscle following acute exercise

2004 ◽  
Vol 18 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Douglas J. Mahoney ◽  
Kate Carey ◽  
Ming-Hua Fu ◽  
Rodney Snow ◽  
David Cameron-Smith ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Real Time ◽  
Healthy Subjects ◽  
Acute Exercise ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Cycle Ergometry ◽  
Pcr Analysis ◽  
28S Rrna ◽  
Rt Pcr

Studies examining gene expression with RT-PCR typically normalize their mRNA data to a constitutively expressed housekeeping gene. The validity of a particular housekeeping gene must be determined for each experimental intervention. We examined the expression of various housekeeping genes following an acute bout of endurance (END) or resistance (RES) exercise. Twenty-four healthy subjects performed either a interval-type cycle ergometry workout to exhaustion (∼75 min; END) or 300 single-leg eccentric contractions (RES). Muscle biopsies were taken before exercise and 3 h and 48 h following exercise. Real-time RT-PCR was performed on β-actin, cyclophilin (CYC), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and β2-microglobulin (β2M). In a second study, 10 healthy subjects performed 90 min of cycle ergometry at ∼65% of V̇o2 max, and we examined a fifth housekeeping gene, 28S rRNA, and reexamined β2M, from muscle biopsy samples taken immediately postexercise. We showed that CYC increased 48 h following both END and RES exercise (3- and 5-fold, respectively; P < 0.01), and 28S rRNA increased immediately following END exercise (2-fold; P = 0.02). β-Actin trended toward an increase following END exercise (1.85-fold collapsed across time; P = 0.13), and GAPDH trended toward a small yet robust increase at 3 h following RES exercise (1.4-fold; P = 0.067). In contrast, β2M was not altered at any time point postexercise. We conclude that β2M and β-actin are the most stably expressed housekeeping genes in skeletal muscle following RES exercise, whereas β2M and GAPDH are the most stably expressed following END exercise.

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