scholarly journals Phormium Yellow Leaf Phytoplasma Is Associated with Strawberry Lethal Yellows Disease in New Zealand

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 606-609 ◽  
Author(s):  
M. T. Andersen ◽  
J. Longmore ◽  
L. W. Liefting ◽  
G. A. Wood ◽  
P. W. Sutherland ◽  
...  
Keyword(s):  
New Zealand ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Leaf Size ◽  
Nucleotide Sequence Analysis ◽  
Rrna Gene ◽  
Yellow Leaf ◽  
Yellow Leaf Disease ◽  
Polymerase Chain ◽  
The 16S Rrna Gene

A yellows disease of strawberry plants was identified in propagation beds in New Zealand. Affected plants were flatter to the ground, showed purpling of older leaves, reduced leaf size, yellowing of younger leaves, and sometimes plant death. A phytoplasma was observed in the phloem of affected plants. The 16S rRNA gene of the phytoplasma was amplified by polymerase chain reaction from symptomatic plants and from one asymptomatic plant, but not from 36 other asymptomatic plants. Nucleotide sequence analysis of the 16S rRNA gene showed that the phytoplasma is closely related or identical to the phytoplasma associated with the yellow leaf disease of New Zealand flax (Phormium tenax).

Phylogenetic analysis identifies a ‘Candidatus Phytoplasma oryzae ’-related strain associated with yellow leaf disease of areca palm (Areca catechu L.) in India

2013 ◽  
Vol 63 (Pt_4) ◽  
pp. 1376-1382 ◽  
Author(s):  
Manimekalai Ramaswamy ◽  
Smita Nair ◽  
V. P. Soumya ◽  
George V. Thomas
Keyword(s):  
16S Rrna ◽  
Type Species ◽  
Rrna Gene ◽  
Yellow Leaf ◽  
Content Type ◽  
Link Type ◽  
Leaf Disease ◽  
White Leaf ◽  
Yellow Leaf Disease ◽  
The 16S Rrna Gene

Yellow leaf disease (YLD) with phytoplasmal aetiology is a serious disease of arecanut palm in India. The present study was undertaken to characterize the 16S rRNA and secA gene sequences of the Indian arecanut YLD phytoplasma for ‘Candidatus Phytoplasma ’ species assignment and 16Sr group/subgroup classification. Phytoplasma 16S rRNA genes were amplified using three sets of semi-nested/nested primers, 1F7/7R3–1F7/7R2, 4Fwd/3Rev–4Fwd/5Rev and P1/P7–R16F2n/R16R2, producing amplicons of 491, 1150 and 1250 bp, respectively, from diseased samples. The amplicons were cloned and sequenced. A blast search showed that the sequences had 99 % similarity with sugar cane white leaf phytoplasma (16SrXI) and Napier grass stunt phytoplasma (16SrXI). Phylogenetic analysis based on the 16S rRNA gene revealed the clustering of YLD phytoplasma with the rice yellow dwarf and Bermuda grass white leaf groups. The YLD phytoplasma F2nR2 sequence shared 97.5 % identity with that of ‘Candidatus Phytoplasma oryzae ’ and 97.8 % identity with that of ‘Candidatus Phytoplasma cynodontis ’. Hence, for finer differentiation, we examined the secA gene-based phylogeny, where the YLD phytoplasma clustered with Napier grass stunt and sugar cane grassy shoot phytoplasmas, both belonging to the rice yellow dwarf group. Hence, we are assigning the Indian arecanut YLD phytoplasma as a ‘Candidatus Phytoplasma oryzae ’-related strain. Virtual RFLP analysis of a 1.2 kb fragment of the 16S rRNA gene (F2nR2 region) identified the Indian arecanut YLD phytoplasma as a member of 16SrXI-B subgroup. We name the phytoplasma Indian yellow leaf disease phytoplasma, to differentiate it from the Hainan YLD phytoplasma, which belongs to group 16SrI.

scholarly journals First Report of “Candidatus Liberibacter solanacearum” on Field Tomatoes in the United States

Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 481-481 ◽  
Author(s):  
R. D. French-Monar ◽  
A. F. Patton ◽  
J. M. Douglas ◽  
J. A. Abad ◽  
G. Schuster ◽  
...  
Keyword(s):  
United States ◽  
New Species ◽  
New Zealand ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
The United States ◽  
Rrna Gene ◽  
Potato Psyllid ◽  
Candidatus Liberibacter ◽  
The 16S Rrna Gene

In August 2008, 30% of tomato (Solanum lycopersicum) plants in plots in Lubbock County, Texas showed yellowing, lateral stem dieback, upward leaf curling, enlargement of stems, adventitious roots, and swollen nodes. Yellowing in leaves was similar to that seen with zebra chip disease (ZC) of potato that was confirmed in a potato field 112 km away in July 2008 and was associated with a ‘Candidatus Liberibacter’ species (1), similar to findings earlier in 2008 in New Zealand and California (2,3). Tissue from four symptomatic plants of cv. Spitfire and two of cv. Celebrity were collected and DNA was extracted from midribs and petioles with a FastDNA Spin Kit (Qbiogene, Inc., Carlsbad, CA,). PCR amplification was done with 16S rRNA gene primers OA2 and OI2c, which are specific for “Ca. Liberibacter solanacearum” from potato and tomato and amplify a 1.1-kb fragment of the 16S rRNA gene of this new species (1,3). Amplicons of 1.1 kb were obtained from all samples and these were sequenced in both orientations (McLab, San Francisco, CA). Sequences of the 16S rRNA gene were identical for both Spitfire and Celebrity and were submitted to the NCBI as GenBank Accession Nos. FJ939136 and FJ939137, respectively. On the basis of a BLAST search, sequence alignments revealed 99.9% identity with a new species of ‘Ca. Liberibacter’ from potato (EU884128 and EU884129) in Texas (1); 99.7% identity with the new species “Ca. Liberibacter solanacearum” described from potato and tomato (3) in New Zealand (EU849020 and EU834130, respectively) and from the potato psyllid Bactericera cockerelli in California (2) (EU812559, EU812556); 97% identity with ‘Ca L. asiaticus’ from citrus in Malaysia (EU224393) and 94% identity with both ‘Ca. L. africanus’ and ‘Ca. L. americanus’ from citrus (EU921620 and AY742824, respectively). A neighbor-joining cladogram constructed using the 16S rRNA gene fragments delineated four clusters corresponding to each species, and these sequences clustered with “Ca. L. solanacearum”. A second PCR analysis was conducted with the CL514F/CL514R primer pair, which amplifies a sequence from the rplJ and rplL ribosomal protein genes of “Ca. L. solanacearum”. The resulting 669-bp products were 100% identical to a sequence reported from tomato in Mexico (FJ498807). This sequence was submitted to NCBI (GU169328). ZC, a disease causing losses to the potato industry, is associated with a ‘Candidatus Liberibacter’ species (1–3) and was reported in Central America and Mexico in the 1990s, in Texas in 2000, and more recently in other states in the United States (4). In 2008, a “Ca. Liberibacter solanacearum” was detected on Capsicum annuum, S. betaceum, and Physalis peruviana in New Zealand (3). Several studies have shown that the potato psyllid, B. cockerelli, is a potential vector for this pathogen (2,4). To our knowledge, this is the first report of “Ca. Liberibacter solanacearum” in field tomatoes showing ZC-like foliar disease symptoms in the United States. References: (1). J. A. Abad et al. Plant Dis. 93:108, 2009 (2) A. K. Hansen et al. Appl. Environ. Microbiol. 74:5862, 2008. (3) L. W. Liefting et al. Plant Dis. 93:208, 2009. (4) G. A. Secor et al. Plant Dis. 93:574, 2009.

Evaluation of lactase activity in new isolated Lactobacillus strains

2019 ◽  
Vol 8 (4) ◽  
pp. 154-161
Author(s):  
Boukezzoula Nawal ◽  
Chaalel Abdelmalek ◽  
Tefiani Choukri ◽  
Bruneau Aurélia ◽  
Gérard Philippe ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Lactose Intolerance ◽  
Lactobacillus Brevis ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Chain Reaction ◽  
Algerian Sahara ◽  
Polymerase Chain ◽  
The 16S Rrna Gene

The aim of this study was to isolate and characterize new Lactobacillus strains in order to check their β-galactosidase activity. A total of 28 strains were isolated from camel and goat milks collected from the Algerian Sahara. These strains were identified with the method of Polymerase Chain Reaction (PCR) of the 16S rRNA gene. Their ability to hydrolyze O-nitrophenyl-β-D ga-lactopyranoside (ONPG) was determined. Cell lysis method involving soni-cation and lysozyme treatment was used for β-galactosidase release from the isolated strains. Analysis of their 16S rRNA gene sequences revealed that the strains clustered in the Lactobacillus genus, 17 isolates were identified as L. plantarum, 10 isolates as L. herbarum and one isolate as L. brevis. The best intracellular enzymatic β-galactosidase activities obtained in descending order are 14.84 (L. plantarum P4), 14.66 (L. plantarum P17), 14.33 (L. planta-rum P12), 14.10 (L. plantarum P10), 13.49 (L. plantarum P6), 12.13 (L. herba-rum H10) and 11.27 (L. plantarum P7) U/mL; while a very low level of this activity was found for Lactobacillus brevis B1. These findings are an argu-ment for the use of these isolated Lactobacilli in the dairy industry in order to alleviate lactose intolerance.

scholarly journals A New ‘Candidatus Liberibacter’ Species in Solanum betaceum (Tamarillo) and Physalis peruviana (Cape Gooseberry) in New Zealand

Plant Disease ◽  
2008 ◽  
Vol 92 (11) ◽  
pp. 1588-1588 ◽  
Author(s):  
L. W. Liefting ◽  
L. I. Ward ◽  
J. B. Shiller ◽  
G. R. G. Clover
Keyword(s):  
New Zealand ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Rrna Gene ◽  
Physalis Peruviana ◽  
Blast Analysis ◽  
Candidatus Liberibacter ◽  
Cape Gooseberry ◽  
The 16S Rrna Gene ◽  
Solanum Betaceum

A new ‘Candidatus Liberibacter’ species was recently identified in tomato, capsicum, and potato in New Zealand. The tomato/potato psyllid, Bactericera cockerelli, is thought to be the vector of this species of liberibacter. During studies to determine additional host plants of the pathogen, leaves of Solanum betaceum (tamarillo, also known as tree tomato) and leaves and stems of Physalis peruviana (cape gooseberry) were collected from a home garden in South Auckland, New Zealand in July of 2008. These plants were not showing any obvious disease symptoms. They were located close to a commercial glasshouse site containing known liberibacter-infected tomatoes, and many psyllids were observed on the tamarillo tree over the summer and until late autumn. Total DNA was extracted from four tamarillo and two cape gooseberry samples with a DNeasy Plant Mini Kit (Qiagen, Valencia, CA). Samples from tamarillo that were used for the extraction were taken from the midveins of old and young leaves and from young petioles. For cape gooseberry, samples were from the leaf midveins and the stems. The samples were tested by PCR using primers OA2 (GenBank Accession No. EU834130) and OI2c (1). These primers amplify a 1,160-bp fragment of the 16S rRNA gene of the new liberibacter species. Amplicons of the expected size were obtained from all four tamarillo samples, with no amplification from negative control tamarillo plants grown from seed in an insect-proof glasshouse. Almost the entire length of the 16S rRNA gene was amplified using primer pairs fD2 (3)/OI2c and OA2/rP1 (3), and the 16S-23S rRNA intergenic spacer was amplified with primer pair OI2/23S1 (2). These amplicons, along with that from the OA2/OI2c primer pair, were directly sequenced, and overlapping fragments were assembled using the SeqMan software of the LaserGene package (DNASTAR, Inc., Madison, WI) (GenBank Accession No. EU935004). A 650-bp fragment of the β operon was also amplified and sequenced directly (GenBank Accession No. EU935005). BLAST analysis showed 100% nt identity to the liberibacter of tomato (GenBank Accession Nos. EU834130 and EU834131) and potato (GenBank Accession Nos. EU849020 and EU919514). The two cape gooseberry samples produced amplicons of the expected size with the 16S rRNA and β operon primers and the origin of the fragments were confirmed by direct sequencing with BLAST analysis showing 100% nt identity to isolates from tomato, potato, and tamarillo. To determine the distribution of disease, 53 samples of 10 leaves each (representing two leaves from five plants) were collected randomly from a commercial tamarillo crop in South Auckland. Small sections of the midveins were removed from each of the 10 leaves, bulked, and DNA was extracted as described above. The samples were tested by PCR using primer pair OA2/OI2c. Amplicons of the expected size were obtained from 2 of the 53 samples. To our knowledge, this is the first report of a liberibacter in tamarillo and cape gooseberry. It is unknown if the liberibacter induces symptoms in these species or if they act as symptomless reservoirs of the pathogen. The infected plants will be observed for symptom development over the course of a growing season. References: (1) S. Jagoueix et al. Mol. Cell. Probes 10:43, 1996. (2) S. Jagoueix et al. Int. J. Syst. Bacteriol. 47:224, 1997. (3) W. G. Weisburg et al. J. Bacteriol. 173:697, 1991.

scholarly journals Phyllobacterium loti sp. nov. isolated from nodules of Lotus corniculatus

2014 ◽  
Vol 64 (Pt_3) ◽  
pp. 781-786 ◽  
Author(s):  
Maximo Sánchez ◽  
Martha-Helena Ramírez-Bahena ◽  
Alvaro Peix ◽  
María J. Lorite ◽  
Juan Sanjuán ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Sequence Similarity ◽  
Carbon Sources ◽  
Lotus Corniculatus ◽  
Culture Conditions ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
The 16S Rrna Gene

Strain S658T was isolated from a Lotus corniculatus nodule in a soil sample obtained in Uruguay. Phylogenetic analysis of the 16S rRNA gene and atpD gene showed that this strain clustered within the genus Phyllobacterium . The closest related species was, in both cases, Phyllobacterium trifolii PETP02T with 99.8 % sequence similarity in the 16S rRNA gene and 96.1 % in the atpD gene. The 16S rRNA gene contains an insert at the beginning of the sequence that has no similarities with other inserts present in the same gene in described rhizobial species. Ubiquinone Q-10 was the only quinone detected. Strain S658T differed from its closest relatives through its growth in diverse culture conditions and in the assimilation of several carbon sources. It was not able to reproduce nodules in Lotus corniculatus. The results of DNA–DNA hybridization, phenotypic tests and fatty acid analyses confirmed that this strain should be classified as a representative of a novel species of the genus Phyllobacterium , for which the name Phyllobacterium loti sp. nov. is proposed. The type strain is S658T( = LMG 27289T = CECT 8230T).

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