| comparison of the 16s/23s ribosomal intergenic regions of "candidatus liberobacter asiaticum" and "candidatus liberobacter africanum," the two species associated with citrus huanglongbing (greening) disease. | 16s/23s intergenic spacer regions from the rrna operons of two strains of "candidatus liberobacter asiaticum" and one strain of "candidatus liberobacter africanum" were cloned and sequenced. the intergenic spacers of the two "candidatus l. asiaticum" strains studied are identical and contain the genes for isoleucine trna (trna(ile)) and alanine trna (trna(ala)) separated by 11 nucleotides. the intergenic spacer of the "candidatus l. africanum" strain contains only one trna gene (trna(ala)). the ... | 1997 | 8995827 |
| production and evaluation of non-radioactive probes for the detection of the two 'candidatus liberobacter' species associated with citrus huanglongbing (greening). | the production and evaluation of non-radioactive probes for the detection of 'candidatus liberobacter asiaticum' and 'candidatus liberobacter africanum', the two bacterial species associated with citrus huanglongbing (greening) disease is described. two dna fagments, in 2.6 and as 1.7, obtained previously from the beta operons of 'candidatus liberobacter asiaticum' and 'candidatus liberobacter africanum', respectively, were the starting materials for production of the two non-radioactive probes. ... | 1997 | 9500815 |
| pcr detection of the two 'candidatus' liberobacter species associated with greening disease of citrus. | greening is a severe and widespread disease of citrus in two main citrus growing areas of the world, asia and africa. it is caused by an uncultured phloem restricted bacterium that we have recently characterized from the sequence of its 16s ribosomal dna. the bacterium is a new "candidatus' genus, liberobacter, in the alpha subdivision of the proteobacteria, and two 'candidatus species' have been recognized: liberobacter asiaticum and liberobacter africanum. in this paper we describe a pcr metho ... | 1996 | 8684375 |
| detection and characterization of the african citrus greening liberobacter by amplification, cloning, and sequencing of the rplkajl-rpobc operon. | greening disease of citrus is caused by a phloem-restricted, uncultured bacterium, recently characterized and named liberobacter. as shown previously, a probe encoding ribosomal protein genes (rplkajl-rpobc operon) from an asian liberobacter could detect all asian liberobacter strains tested, but not african strains. using the sequence of the rplkajl-rpobc operon of the asian liberobacter strain from poona (india), we have defined primers for pcr amplification of the equivalent genes of an afric ... | 1995 | 7765847 |
| the phloem-limited bacterium of greening disease of citrus is a member of the alpha subdivision of the proteobacteria. | using the pcr, we amplified the 16s ribosomal dnas (rdnas) of an asian strain and an african strain of the uncultured, gram-negative, walled, phloem-limited bacterium-like organism (blo) associated with citrus greening disease. we evaded coamplification of chloroplast 16s rdna by using restriction enzymes; the chloroplast 16s rdna was sensitive to bcli digestion and resistant to ecori digestion, while the 16s rdna of the blo was resistant to bcli digestion and sensitive to ecori digestion. the 1 ... | 1994 | 7520729 |
| sequestering from host and characterization of sequence of a ribosomal rna operon (rrn) from "candidatus liberibacter asiaticus". | a 5005bp rrn dna sequence of "candidatus liberibacter asiaticus" was obtained by pcr using primers conserved to rhizobiaceae of alpha-proteobacteria. the rrn locus consisted of a 16s rrna gene (rrs), an intergenic transcribed spacer (its) containing two genes of trna(ile) and trna(ala), a 23s rrna gene (rrl), an its without trna gene and a 5s rrna gene (rrf). like rrs, rrl and rrf were also related (89-90%) to those of the members of rhizobiaceae. interestingly, the genes of trna(ile) and trna(a ... | 2008 | 18955129 |
| detection of 'candidatus liberibacter asiaticus' in diaphorina citri and its importance in the management of citrus huanglongbing in florida. | citrus huanglongbing (hlb or citrus greening), is a highly destructive disease that has been spreading in both florida and brazil. its psyllid vector, diaphorina citri kuwayama, has spread to texas and mexico, thus threatening the future of citrus production elsewhere in mainland north america. even though sensitive diagnostic methods have been developed for detection of the causal organisms, candidatus liberibacter spp., the pathogen cannot be detected consistently in plants until symptoms deve ... | 2008 | 18944186 |
| a phytoplasma closely related to the pigeon pea witches'-broom phytoplasma (16sr ix) is associated with citrus huanglongbing symptoms in the state of são paulo, brazil. | in february 2007, sweet orange trees with characteristic symptoms of huanglongbing (hlb) were encountered in a region of são paulo state (sps) hitherto free of hlb. these trees tested negative for the three liberibacter species associated with hlb. a polymerase chain reaction (pcr) product from symptomatic fruit columella dna amplifications with universal primers fd1/rp1 was cloned and sequenced. the corresponding agent was found to have highest 16s rdna sequence identity (99%) with the pigeon p ... | 2008 | 18943735 |
| in planta distribution of 'candidatus liberibacter asiaticus' as revealed by polymerase chain reaction (pcr) and real-time pcr. | huanglongbing (hlb) is one of the most devastating diseases of citrus worldwide, and is caused by a phloem-limited fastidious prokaryotic alpha-proteobacterium that is yet to be cultured. in this study, a combination of traditional polymerase chain reaction (pcr) and real-time pcr targeting the putative dna polymerase and 16s rdna sequence of 'candidatus liberibacter asiaticus,' respectively, were used to examine the distribution and movement of the hlb pathogen in the infected citrus tree. we f ... | 2008 | 18943228 |
| comparative phylogenomics and multi-gene cluster analyses of the citrus huanglongbing (hlb)-associated bacterium candidatus liberibacter. | huanglongbing (hlb, previously known as citrus greening), is associated with candidatus liberibacter species and is a serious threat to citrus production world-wide. the pathogen is a gram negative, unculturable, phloem-limited bacterium with limited known genomic information. expanding the genetic knowledge of this organism may provide better understanding of the pathogen and possibly develop effective strategies for control and management of hlb. | 2008 | 18755041 |
| a new huanglongbing species, "candidatus liberibacter psyllaurous," found to infect tomato and potato, is vectored by the psyllid bactericera cockerelli (sulc). | a new huanglongbing (hlb) "candidatus liberibacter" species is genetically characterized, and the bacterium is designated "candidatus liberibacter psyllaurous." this bacterium infects the psyllid bactericera cockerelli and its solanaceous host plants potato and tomato, potentially resulting in "psyllid yellowing." host plant-dependent hlb transmission and variation in psyllid infection frequencies are found. | 2008 | 18676707 |
| multiplex real-time pcr for detection, identification and quantification of 'candidatus liberibacter solanacearum' in potato plants with zebra chip. | the new liberibacter species, 'candidatus liberibacter solanacearum' (lso) recently associated with potato/tomato psyllid-transmitted diseases in tomato and capsicum in new zealand, was found to be consistently associated with a newly emerging potato zebra chip (zc) disease in texas and other southwestern states in the usa. a species-specific primer lsof was developed for both quantitative real-time pcr (qpcr) and conventional pcr (cpcr) to detect and quantify lso in infected samples. in multipl ... | 2009 | 19409423 |
| morphological characterization of the antennal sensilla of the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), with reference to their probable functions. | the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is one of the most significant economic pests of citrus worldwide. this insect vectors three phloem-restricted bacteria in the genus candidatus liberibacter that cause huanglongbing (citrus greening), the most severe disease limiting citrus production worldwide. we examined the external morphology of the antennal sensilla of male and female d. citri using scanning electron microscopy (sem) and determined the putative fun ... | 2008 | 18573664 |
| rate, placement and timing of aldicarb applications to control asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), in oranges. | the asian citrus psyllid (acp), diaphorina citri kuwayama (hemiptera: psyllidae), is a cosmopolitan insect pest of citrus and vectors the bacterium candidatus liberibacter asiaticus, a suspected causal organism of citrus greening or 'huanglongbing' disease. aldicarb 150 g kg(-1) gr (temik((r)) 15 g) was evaluated at three rates, two placements and three timings for acp control in orange trees. | 2008 | 18537108 |
| the tufb-sece-nusg-rplkajl-rpob gene cluster of the liberibacters: sequence comparisons, phylogeny and speciation. | the rplkajl-rpobc operon or beta operon is a classic bacterial gene cluster, which codes for proteins k, a, j and l of the large ribosomal subunit, as well as proteins b (beta subunit) and c (beta' subunit) of rna polymerase. in the early 1990s, the operon was obtained as a 2.6 kbp dna fragment (in-2.6) by random cloning of dna from periwinkle plants infected with the poona (india) strain of the huanglongbing agent, later named 'candidatus (ca.) liberibacter asiaticus'. dna from periwinkle plant ... | 2008 | 18523188 |
| distribution and quantification of candidatus liberibacter americanus, agent of huanglongbing disease of citrus in são paulo state, brasil, in leaves of an affected sweet orange tree as determined by pcr. | huanglongbing (hlb), an insect-transmitted disease of citrus, known for many years in asia and africa, has appeared in the state of são paulo state (ssp), brazil, in 2004, and the state of florida, usa, in 2005. hlb endangers the very existence of citrus, as trees infected with the bacterial pathogen, irrevocably decline. in the absence of curative procedures, control of hlb is difficult and only based on prevention. even though not available in culture, the hlb bacterium could be shown to be gr ... | 2008 | 18400468 |
| vitrification-cryopreservation, an efficient method for eliminating candidatus liberobacter asiaticus, the citrus huanglongbing pathogen, from in vitro adult shoot tips. | huanglongbing disease (hlb), caused by candidatus liberobacter asiaticus, constitutes a most serious problem for the chinese citrus industry. in this work, the use of vitrification-cryopreservation for eliminating ca. l. asiaticus from naturally infected plants of several citrus species was investigated. proliferating meristems were produced in vitro and excised tissue clumps were cryopreserved through vitrification using a plant vitrification solution 2. the health status of regenerated in vitr ... | 2008 | 17955244 |
| acquisition of uncharacterized sequences from candidatus liberibacter, an unculturable bacterium, using an improved genomic walking method. | an effective pcr-based genomic walking approach is described to discover previously unknown flanking genomic dna sequences from candidatus liberibacter asiaticus, an unculturable, phloem-limited bacterium. using this technique, 8564bp of new dna sequences were obtained from three genomic loci; tufb-sece-nusg-rplkajl-rpobc gene cluster, omp gene (outer membrane protein, omp) and 16/23s rrna gene in ca. l. asiaticus. these, together with publicly available ca. liberibacter sequences, are clustered ... | 2008 | 17689920 |
| etiology of three recent diseases of citrus in são paulo state: sudden death, variegated chlorosis and huanglongbing. | the state of são paulo (ssp) is the first sweet orange growing region in the world. yet, the ssp citrus industry has been, and still is, under constant attack from various diseases. in the 1940s, tristeza-quick decline (t-qd) was responsible for the death of 9 million trees in ssp. the causal agent was a new virus, citrus tristeza virus (ctv). the virus was efficiently spread by aphid vectors, and killed most of the trees grafted on sour orange rootstock. control of the disease resided in replac ... | 2007 | 17505974 |
| quantitative real-time pcr for detection and identification of candidatus liberibacter species associated with citrus huanglongbing. | citrus huanglongbing (hlb, ex greening) is one of the most serious diseases of citrus. different forms of the disease are caused by different candidatus liberobacter species, candidatus liberibacter asiaticus (las), ca. l. africanus (laf) and ca. l. americanus (lam). the pathogen is transmitted by psyllid insects and by budding with contaminated plant materials. the vector psyllid diaphorina citri can transmit both las and lam. establishment of this vector into florida, reports of lam and las in ... | 2006 | 16414133 |
| diversity of "candidatus liberibacter asiaticus," based on the omp gene sequence. | huanglongbing (yellow dragon disease) is a destructive disease of citrus. the etiological agent is a noncultured, phloem-restricted alpha-proteobacterium, "candidatus liberibacter africanus" in africa and "candidatus liberibacter asiaticus" in asia. in this study, we used an omp-based pcr-restriction fragment length polymorphism (rflp) approach to analyze the genetic variability of "ca. liberibacter asiaticus" isolates. by using five different enzymes, each the 10 isolates tested could be associ ... | 2005 | 16269671 |
| rapid, specific and quantitative assays for the detection of the endophytic bacterium methylobacterium mesophilicum in plants. | xylella fastidiosa is a xylem-limited bacterium that causes citrus variegated chlorosis disease in sweet orange. there is evidence that x. fastidiosa interacts with endophytic bacteria present in the xylem of sweet orange, and that these interactions, particularly with methylobacterium mesophilicum, may affect disease progress. however, these interactions cannot be evaluated in detail until efficient methods for detection and enumeration of these bacteria in planta are developed. we have previou ... | 2006 | 16266765 |
| 'candidatus liberibacter americanus', associated with citrus huanglongbing (greening disease) in são paulo state, brazil. | symptoms of huanglongbing (hlb) were reported in são paulo state (sps), brazil, in march 2004. in asia, hlb is caused by 'candidatus liberibacter asiaticus' and in africa by 'candidatus liberibacter africanus'. detection of the liberibacters is based on pcr amplification of their 16s rrna gene with specific primers. leaves with blotchy mottle symptoms characteristic of hlb were sampled in several farms of sps and tested for the presence of liberibacters. 'ca. l. asiaticus' was detected in a smal ... | 2005 | 16166678 |
| citrus huanglongbing in são paulo state, brazil: pcr detection of the 'candidatus' liberibacter species associated with the disease. | symptoms of huanglongbing (hlb), one of the most serious diseases of citrus in asia and africa, have been noticed in march 2004 in the araraquara region of são paulo state, brazil. hlb has not been reported previously from america. the causal hlb bacteria, candidatus liberibacter africanus in africa and candidatus liberibacter asiaticus in asia, can be detected in symptomatic citrus leaves by pcr amplification of their 16s rdna with previously described primers. when this technique was applied t ... | 2005 | 15797817 |
| effect of sucrose octanoate on survival of nymphal and adult diaphorina citri (homoptera: psyllidae). | asian citrus psylla, diaphorina citri kuwayama (homoptera: psyllidae) was detected for the first time in the united states near delray beach, fl, on 2 june 1998 and is continuing to spread and multiply throughout southern florida. this psyllid is the vector of liberobacter asiaticum, a phloem-limited bacterium that causes citrus greening disease. this pathogen has not been found in the western hemisphere to date. furthermore, high infestation levels of d. citri can impact citrus plant health, fr ... | 2004 | 15279280 |
| genomic characterization of a liberibacter present in an ornamental rutaceous tree, calodendrum capense, in the western cape province of south africa. proposal of 'candidatus liberibacter africanus subsp. capensis'. | in 1994, the uncultured phloem-restricted bacteria of citrus huanglongbing (ex-greening) disease in asia and africa were characterized as 'candidatus liberobacter asiaticum' and 'candidatus liberobacter africanum', respectively. following the rules of the international code of nomenclature of bacteria, the two bacterial species have now been renamed 'candidatus liberibacter asiaticus' and 'candidatus liberibacter africanus'. a third liberibacter was detected by pcr in an ornamental rutaceous tre ... | 2000 | 11155987 |
| detection and identification of the two candidatus liberobacter species associated with citrus huanglongbing by pcr amplification of ribosomal protein genes of the beta operon. | huanglongbing, previously called greening, is a destructive disease of citrus in asia and africa. it is caused by an uncultured, phloem-restricted bacterium for which two species candidatus liberobacter asiaticum and candidatus liberobacter africanum have been characterized. in 1996, a polymerase chain reaction (pcr) detection method based on the amplification of the 16s ribosomal operon was developed and proved to be efficient for the detection of both liberobacter species. however, in order to ... | 1999 | 10508559 |
| isolation of dna from the uncultured "candidatus liberobacter" species associated with citrus huanglongbing by rapd. | "candidatus liberobacter," the uncultured bacterium associated with citrus huanglongbing (hlb) disease, is an alpha-proteobacteria, and two species, "candidatus l. africanum" and "candidatus l. asiaticum, " have been characterized by sequence analysis of the 16s rdna and beta operon (rplkajl-rpobc) genes. these genes were isolated by pcr and random cloning of dna from infected plants. however, this strategy is laborious and allowed selection of only three liberobacter dna fragments. in this pape ... | 1999 | 9922469 |
| guangdong and florida populations of 'candidatus liberibacter asiaticus' distinguished by a genomic locus with short tandem repeats. | huanglongbing (hlb) (yellow shoot disease) is a highly destructive disease that threatens citrus production worldwide. the disease was first observed in guangdong, p.r. china, over 100 years ago, and was found in florida, united states, in 2005. 'candidatus liberibacter asiaticus' has been associated with hlb in many citrus-growing regions around the world, including guangdong and florida. the global epidemiology of hlb, as well as management of the disease, relies on knowledge of 'ca. l. asiati ... | 2010 | 20465412 |
| response of sweet orange (citrus sinensis) to 'candidatus liberibacter asiaticus' infection: microscopy and microarray analyses. | citrus greening or huanglongbing (hlb) is a devastating disease of citrus. hlb is associated with the phloem-limited fastidious prokaryotic alpha-proteobacterium 'candidatus liberibacter spp.' in this report, we used sweet orange (citrus sinensis) leaf tissue infected with 'ca. liberibacter asiaticus' and compared this with healthy controls. investigation of the host response was examined with citrus microarray hybridization based on 33,879 expressed sequence tag sequences from several citrus sp ... | 2009 | 19055434 |
| bacterial diversity analysis of huanglongbing pathogen-infected citrus, using phylochip arrays and 16s rrna gene clone library sequencing. | the bacterial diversity associated with citrus leaf midribs was characterized for citrus groves that contained the huanglongbing (hlb) pathogen, which has yet to be cultivated in vitro. we employed a combination of high-density phylogenetic 16s rrna gene microarrays and 16s rrna gene clone library sequencing to determine the microbial community composition for symptomatic and asymptomatic citrus midribs. our results revealed that citrus leaf midribs can support a diversity of microbes. phylochip ... | 2009 | 19151177 |
| a phytoplasma related to 'candidatus phytoplasma asteri' detected in citrus showing huanglongbing (yellow shoot disease) symptoms in guangdong, p. r. china. | citrus huanglongbing (hlb) or yellow shoot disease (i.e., greening disease) is highly destructive to citrus production worldwide. understanding the etiology of hlb is critical for managing the disease. hlb is currently associated with infection by 'candidatus liberibacter spp.' around the world, including china. however, koch's postulates have not been fulfilled. in addition, other plant pathogens also may be involved in hlb. in a survey performed in guangdong province, p. r. china in 2006 and 2 ... | 2009 | 19203275 |
| graft transmission efficiencies and multiplication of 'candidatus liberibacter americanus' and 'ca. liberibacter asiaticus' in citrus plants. | in brazil 'candidatus liberibacter asiaticus' and 'ca. l. americanus' cause huanglongbing (also known as greening), the most destructive citrus disease. a shift in pathogen prevalence was observed over time, with a disproportional increase in 'ca. l. asiaticus' occurrence. graft transmission experiments were used for a comparative study of both species using budsticks from symptomatic branches of field-affected trees as inoculum. the plants were inoculated with 'ca. l. asiaticus' or 'ca. l. amer ... | 2009 | 19203283 |
| incidence of invasive diaphorina citri (hemiptera: psyllidae) and its introduced parasitoid tamarixia radiata (hymenoptera: eulophidae) in florida citrus. | diaphorina citri kuwayama (hemiptera: psyllidae), vectors the bacterium candidatus liberibacter asiaticus, one of the causal organisms of the devastating citrus disease "huanglongbing" or citrus greening. in the united states, d. citri was first discovered in florida, in 1998. tamarixia radiata waterston (hymenoptera: eulophidae) was imported from asia and released in florida in 1999-2001 to improve biological control of d. citri before citrus greening was detected in florida in 2005. florida ci ... | 2009 | 19253643 |
| characterization of copy numbers of 16s rdna and 16s rrna of candidatus liberibacter asiaticus and the implication in detection in planta using quantitative pcr. | citrus huanglongbing (hlb) is one of the most devastating diseases on citrus and is associated with candidatus liberibacter spp.. the pathogens are phloem limited and have not been cultured in vitro. the current management strategy of hlb is to remove infected citrus trees and reduce psyllid populations with insecticides to prevent the spreading. this strategy requires sensitive and reliable diagnostic methods for early detection. | 2009 | 19284534 |
| cultivation of 'candidatus liberibacter asiaticus', 'ca. l. africanus', and 'ca. l. americanus' associated with huanglongbing. | a new medium designated liber a has been designed and used to successfully cultivate all three 'candidatus liberibacter spp.,' the suspect causative agents of huanglongbing (hlb) in citrus. the medium containing citrus vein extract and a growth factor sustained growth of 'ca. liberibacter spp.' for four or five single-colony transfers before viability declined. colonies, positive for 'ca. l. asiaticus' by a 16s-based rdna real-time polymerase chain reaction (rt-pcr) assay and sequencing, were ir ... | 2009 | 19351243 |
| establishment of asian citrus psyllid (diaphorina citri) primary cultures. | the asian citrus psyllid (ascp), diaphorina citri kuwayama (hemiptera: psyllidae), is a highly competent vector of the phloem-inhabiting bacterium candidatus liberibacter asiaticus associated with the citrus disease huanglongbing (hlb). commonly referred to as citrus greening disease in the usa, hlb causes reduced fruit yields, quality, and ultimately tree death and is considered the most serious citrus disease. hlb has become a major limiting factor to the production of citrus worldwide. studie ... | 2009 | 19440802 |
| influence of posttreatment temperature on the toxicity of insecticides against diaphorina citri (hemiptera: psyllidae). | the psyllid diaphorina citri kuwayama (hemiptera: psyllidae) is one of the most important pests of citrus worldwide because it efficiently vectors three bacteria in the genus candidatus liberibacter that cause the devastating citrus greening disease (huanglongbing). current management practices for this insect pest rely on multiple sprays of foliar insecticides and one or two applications of soil systemic insecticides per season. effective psyllid and disease management in florida requires insec ... | 2009 | 19449650 |
| rrna operons and genome size of 'candidatus liberibacter americanus', a bacterium associated with citrus huanglongbing in brazil. | huanglongbing is one of the most severe diseases of citrus worldwide and is associated with 'candidatus (ca.) liberibacter africanus' in africa, 'ca. liberibacter asiaticus' in asia and the americas (brazil, usa and cuba) and 'ca. liberibacter americanus' (lam) in brazil. in the absence of axenic cultures, genetic information on liberibacters is scarce. the sequences of the entire 23s rrna and 5s rrna genes from lam have now been obtained, using a consensus primer designed on known trnamet seque ... | 2009 | 19567586 |
| complete genome sequence of citrus huanglongbing bacterium, 'candidatus liberibacter asiaticus' obtained through metagenomics. | citrus huanglongbing is the most destructive disease of citrus worldwide. it is spread by citrus psyllids and is associated with a low-titer, phloem-limited infection by any of three uncultured species of alpha-proteobacteria, 'candidatus liberibacter asiaticus', 'ca. l. americanus', and 'ca. l. africanus'. a complete circular 'ca. l. asiaticus' genome has been obtained by metagenomics, using the dna extracted from a single 'ca. l. asiaticus'-infected psyllid. the 1.23-mb genome has an average 3 ... | 2009 | 19589076 |
| 'candidatus liberibacter solanacearum', associated with plants in the family solanaceae. | a liberibacter (isolate nz082226) was detected in a symptomatic tomato plant and subsequently in five other members of the family solanaceae: capsicum, potato, tamarillo, cape gooseberry and chilli. phylogenetic analyses of the 16s rrna gene sequence, the deduced amino acid sequence of the rplj gene and a partial nucleotide sequence of the beta operon indicated that isolate nz082226 represents a novel candidate species of 'candidatus liberibacter', for which the name 'candidatus liberibacter sol ... | 2009 | 19620372 |
| evaluation of genetic diversity among 'candidatus liberibacter asiaticus' isolates collected in southeast asia. | the aim of this study was to investigate the genetic diversity and relationships among 'candidatus liberibacter asiaticus' isolates from different hosts and distinct geographical areas in southeast asia. genetic diversity among 'ca. liberibacter asiaticus' was estimated by sequencing four well-characterized dna fragments: the 16s ribosomal dna (rdna) and 16s/23s intergenic spacer regions; the outer membrane protein (omp) gene region; the trmu-tufb-sece-nusg-rplkajl-rpob region (gene cluster regi ... | 2009 | 19671008 |
| roles of olfactory cues, visual cues, and mating status in orientation of diaphorina citri kuwayama (hemiptera: psyllidae) to four different host plants. | diaphorina citri kuwayama (hemiptera: psyllidae) is an important worldwide pest of citrus that vectors bacteria (candidatus liberibacter spp.) responsible for huanglongbing (citrus greening disease). we examined the behavioral responses of mated and unmated d. citri of both sexes to odors from host plants in a y-tube olfactometer, with and without visual cues. the host plants tested were 'duncan' grapefruit (citrus paradisi macfayden), sour orange (citrus aurantium l.), navel orange (c. sinensis ... | 2009 | 19791618 |
| confirmation of the sequence of 'candidatus liberibacter asiaticus' and assessment of microbial diversity in huanglongbing-infected citrus phloem using a metagenomic approach. | the citrus disease huanglongbing (hlb) is highly destructive in many citrus-growing regions of the world. the putative causal agent of this disease, 'candidatus liberibacter asiaticus', is difficult to culture, and koch's postulates have not yet been fulfilled. as a result, efforts have focused on obtaining the genome sequence of 'ca. l. asiaticus' in order to give insight on the physiology of this organism. in this work, three next-generation high-throughput sequencing platforms, 454, solexa, a ... | 2009 | 19888827 |
| examination of the responses of different genotypes of citrus to huanglongbing (citrus greening) under different conditions. | abstract citrus huanglongbing (hlb) is one of the most devastating diseases of citrus worldwide. the causal agent of hlb in florida is thought to be 'candidatus liberibacter asiaticus'. in this work, we examined the responses of 30 different genotypes of citrus to florida isolates of 'ca. l. asiaticus' under controlled conditions in the greenhouse or growth room. although 'ca. l. asiaticus' was able to multiply in all of the plants, a wide range of responses was observed among different hosts. b ... | 2009 | 19900000 |
| characterization of an atp translocase identified in the destructive plant pathogen "candidatus liberibacter asiaticus". | atp/adp translocases transport atp across a lipid bilayer, which is normally impermeable to this molecule due to its size and charge. these transport proteins appear to be unique to mitochondria, plant plastids, and obligate intracellular bacteria. all bacterial atp/adp translocases characterized thus far have been found in endosymbionts of protozoa or pathogens of higher-order animals, including humans. a putative atp/adp translocase was uncovered during the genomic sequencing of the intracellu ... | 2010 | 19948801 |
| effect of liberibacter infection (huanglongbing disease) of citrus on orange fruit physiology and fruit/fruit juice quality: chemical and physical analyses. | more than 90% of oranges in florida are processed, and since huanglongbing (hlb) disease has been rumored to affect fruit flavor, chemical and physical analyses were conducted on fruit and juice from healthy (las -) and diseased (las +) trees on three juice processing varieties over two seasons, and in some cases several harvests. fruit, both asymptomatic and symptomatic for the disease, were used, and fresh squeezed and processed/pasteurized juices were evaluated. fruit and juice characteristic ... | 2010 | 20030384 |
| a new diagnostic system for ultra-sensitive and specific detection and quantification of candidatus liberibacter asiaticus, the bacterium associated with citrus huanglongbing. | an ultra-sensitive and quantitative diagnostic system by combining nested pcr and taqman pcr in a single tube was developed for detection of "candidatus liberibacter asiaticus". the procedure involves two pcr steps using the species-specific outer and inner primer pairs. different annealing temperatures allow both the first and the second rounds of pcr to be performed sequentially in the same closed tube. the first pcr with outer primers was performed at a higher annealing temperature and with l ... | 2010 | 20096734 |
| isolation and characterization of beneficial bacteria associated with citrus roots in florida. | cultivable diversity of bacteria associated with citrus was investigated as part of a larger study to understand the roles of beneficial bacteria and utilize them to increase the productive capacity and sustainability of agro-ecosystems. citrus roots from huanglongbing (hlb) diseased symptomatic and asymptomatic citrus were used in this study. a total of 227 and 125 morphologically distinct colonies were isolated and characterized from hlb asymptomatic and symptomatic trees, respectively. we obs ... | 2011 | 21360139 |
| screening molecules for control of citrus huanglongbing using an optimized regeneration system for 'candidatus liberibacter asiaticus'-infected periwinkle (catharanthus roseus) cuttings. | citrus huanglongbing is one of the most destructive diseases of citrus worldwide. the disease is associated with three different species of 'candidatus liberibacter', of which 'ca. l. asiaticus' is the most widely distributed. an optimized system using 'ca. l. asiaticus'-infected periwinkle cuttings was developed to screen chemical compounds effective for controlling the bacterial population while simultaneously assessing their phytotoxicity. the optimal regeneration conditions were determined t ... | 2010 | 20128697 |
| huanglongbing, a systemic disease, restructures the bacterial community associated with citrus roots. | to examine the effect of pathogens on the diversity and structure of plant-associated bacterial communities, we carried out a molecular analysis using citrus and huanglongbing as a host-disease model. 16s rrna gene clone library analysis of citrus roots revealed shifts in microbial diversity in response to pathogen infection. the clone library of the uninfected root samples has a majority of phylotypes showing similarity to well-known plant growth-promoting bacteria, including caulobacter, burkh ... | 2010 | 20382817 |
| responses of the asian citrus psyllid to volatiles emitted by the flushing shoots of its rutaceous host plants. | diaphorina citri kuwayama (hemiptera: psyllidae) carries candidatus liberibacter spp., the putative causal agents of huanglongbing. d. citri reproduces and develops only on the flushing shoots of its rutaceous host plants. here we examined whether d. citri is attracted to host plant odors and a mixture of synthetic terpenes. tests conducted in a vertically oriented y-tube olfactometer showed that both males and females preferentially entered the y-tube arm containing the odor from the young shoo ... | 2010 | 20388295 |
| quantitative distribution of 'candidatus liberibacter asiaticus' in citrus plants with citrus huanglongbing. | citrus huanglongbing (hlb), or greening disease, is strongly associated with any of three nonculturable gram-negative bacteria belonging to 'candidatus liberibacter spp.' 'ca. liberibacter spp.' are transmitted by citrus psyllids to all commercial cultivars of citrus. the diseases can be lethal to citrus and have recently become widespread in both são paulo, brazil, and florida, united states, the locations of the largest citrus industries in the world. asiatic hlb, the form of the disease found ... | 2009 | 19159305 |
| colonization of dodder, cuscuta indecora, by 'candidatus liberibacter asiaticus' and 'ca. l. americanus'. | huanglongbing, or citrus greening, threatens the global citrus industry. the presumptive pathogens, 'candidatus liberibacter asiaticus' and 'ca. l. americanus' can be transferred from citrus to more easily studied experimental hosts by using holoparasitic dodder plants. however, the interaction between 'candidatus liberibacter' spp. and the dodder has not been studied. we combined quantitative polymerase chain reaction with electron microscopy to show that only 65% of tendrils of cuscuta indecor ... | 2010 | 20626279 |
| [ovarian development and analysis of mating effects on ovary maturation of diaphorina citri kuwayama (hemiptera: psyllidae)]. | as many other insects with a restricted diet, the citrus psyllid diaphorina citri kuwayama, which vector the causing agent of the huanglongbing, the bacteria candidatus liberibacter spp., is intimately associated with symbiotic microorganisms. these mutualist symbionts play a key role on their host nutritional ecology, and are vertically transmitted to the progeny. however, despite the role symbionts play on host development and reproduction, and the growing opportunities of exploitation of the ... | 2010 | 20676515 |
| early events of citrus greening (huanglongbing) disease development at the ultrastructural level. | citrus greening (huanglongbing [hlb]) is one of the most destructive diseases of citrus worldwide. the causal agent of hlb in florida is thought to be 'candidatus liberibacter asiaticus'. understanding of the early events in hlb infection is critical for the development of effective measures to control the disease. in this work, we conducted cytopathological studies by following the development of the disease in citrus trees graft inoculated with 'ca. l. asiaticus'-containing material under gree ... | 2010 | 20701493 |
| association of "candidatus liberibacter solanacearum" with the psyllid, trioza apicalis (hemiptera: triozidae) in europe. | the psyllid trioza apicalis förster (hemiptera: triozidae) is a serious pest of carrots, daucus carota l., in europe. carrots exhibiting symptoms of psyllid damage were observed in commercial fields in southern finland in 2008. symptoms in affected plants included leaf curling, yellow and purple discoloration of leaves, stunted growth of shoots and roots, and proliferation of secondary roots. mechanisms by which t. apicalis induces symptoms in plants are not understood, and no plant pathogens ha ... | 2010 | 20857712 |
| comparative itraq proteome and transcriptome analyses of sweet orange infected by candidatus liberibacter asiaticus. | citrus huanglongbing (hlb) has been threatening citrus production worldwide. in this study, a comparative proteomic approach was applied to understand the pathogenic process of hlb in affected sweet orange leaves. using the isobaric tags for relative and absolute quantification (itraq) technique, we identified 686 unique proteins in the mature leaves of both mock-inoculated and diseased 'madam vinous' sweet orange plants. of the identified proteins, 20 and 10 were differentially expressed in lea ... | 2011 | 21838733 |
| effects of pymetrozine, an antifeedant of hemiptera, on asian citrus psyllid, diaphorina citri, feeding behavior, survival and transmission of candidatus liberibacter asiaticus. | vector-borne plant disease management can be enhanced by deployment of antifeedants in addition to the use of broad-spectrum neurotoxic insecticides. the effects of pymetrozine on asian citrus psyllid (acp), diaphorina citri kuwayama, feeding behaviour, survival and transmission of candidatus liberibacter asiaticus (las), the presumed causal pathogen of huanglongbing, were investigated. | 2010 | 20960465 |
| effect of candidatus liberibacter asiaticus infection on susceptibility of asian citrus psyllid, diaphorina citri, to selected insecticides. | in the present investigation, the effect of candidatus liberibacter asiaticus (las), a bacterium considered to be responsible for causing huanglongbing (hlb) disease in citrus, on the physiology of its vector, the asian citrus psyllid (acp) diaphorina citri kuwayama, was determined. specifically, the effects of las infection on the susceptibility of acp to selected insecticides were determined. furthermore, total protein content and general esterase activity were quantified in las-infected and u ... | 2010 | 20960471 |
| 'candidatus liberibacter europaeus' sp. nov. that is associated with and transmitted by the psyllid cacopsylla pyri apparently behaves as an endophyte rather than a pathogen. | 'candidatus liberibacter spp.' cause serious plant diseases. 'candidatus liberibacter asiaticus', 'ca. l. americanus' and 'ca. l. africanus' are the aetiological agents of citrus greening (huanglongbing) in asia, america and africa. 'candidatus liberibacter solanacearum' causes diseases in solanaceae in america and new zealand. all four species are vectored by psyllid insects of different genera. here, we show that the pear psyllid pest cacopsylla pyri (l.) hosts a novel liberibacter species tha ... | 2010 | 21040355 |
| movement of bactericera cockerelli (heteroptera: psyllidae) in relation to potato canopy structure, and effects on potato tuber weights. | with the threat of new plant diseases on the increase, plant disease epidemiology requires research on pathogen vector movement. here, releases were performed in planted potato fields of different ages and canopy structures, located in the texas panhandle, to evaluate the range of movement of the potato psyllid bactericera cockerelli (sulc.). this insect is a known causative agent of psyllid yellows disease, and is a vector of the reported etiological agents of zebra chip disease of potato, 'can ... | 2010 | 21061949 |
| transmission parameters for candidatus liberibacter asiaticus by asian citrus psyllid (hemiptera: psyllidae). | the purpose of this investigation was to evaluate acquisition and inoculation (together, transmission) efficiency of candidatus liberibacter asiaticus (las), the pathogen associated with citrus huanglongbing (hlb) by the asian citrus psyllid, diaphorina citri (kuwayama) (hemiptera: psyllidae). in laboratory studies, nymphs reared on las infected plants were more likely to acquire the bacterium than adults. acquisition by nymphs ranged from 60 to 100%, whereas acquisition by adults only reached 4 ... | 2010 | 21061950 |
| life history and life tables of bactericera cockerelli (hemiptera: psyllidae) on potato under laboratory and field conditions in the lower rio grande valley of texas. | effective management of potato 'zebra chip' (zc) disease caused by cadidatus liberibacter psyllaurous (syn. solanacearum) depends on the management of its insect vector insect, potato psyllid, bactericera cockerelli (sulc) (hemiptera: psyllidae). to elucidate the age-specific population dynamics of b. cockerelli, the life-table parameters were determined on potato, solanum tuberosum l., under both laboratory and field conditions in the lower rio grande valley (lrgv) of texas. generally, survival ... | 2010 | 21061973 |
| evaluation of the effects of candidatus liberibacter asiaticus on inoculated citrus plants using laser-induced breakdown spectroscopy (libs) and chemometrics tools. | this study investigated the organic and inorganic constituents of healthy leaves and candidatus liberibacter asiaticus (clas)-inoculated leaves of citrus plants. the bacteria clas are one of the causal agents of citrus greening (or huanglongbing) and its effect on citrus leaves was investigated using laser-induced breakdown spectroscopy (libs) combined with chemometrics. the information obtained from the libs spectra profiles with chemometrics analysis was promising for the construction of predi ... | 2010 | 21111145 |
| 'ca. liberibacter asiaticus' carries an excision plasmid prophage and a chromosomally integrated prophage that becomes lytic in plant infections. | huanglongbing (hlb), also known as citrus greening, is a lethal disease of citrus caused by several species of 'candidatus liberibacter', a psyllid-transmitted, phloem-limited, alpha proteobacteria. 'ca. liberibacter asiaticus' is widespread in florida citrus. the recently published 'ca. l. asiaticus' psy62 genome, derived from a psyllid, revealed a prophage-like region of dna in the genome, but phage have not been associated with 'ca. l. asiaticus' to date. in the present study, shotgun sequenc ... | 2011 | 21190436 |
| differentiation of "candidatus liberibacter asiaticus" isolates by variable-number tandem-repeat analysis. | four highly polymorphic simple sequence repeat (ssr) loci were selected and used to differentiate 84 japanese isolates of "candidatus liberibacter asiaticus." the nei's measure of genetic diversity values for these four ssrs ranged from 0.60 to 0.86. the four ssr loci were also highly polymorphic in four isolates from taiwan and 12 isolates from indonesia. | 2011 | 21239554 |
| incidence of candidatus liberibacter asiaticus infection in abandoned citrus occurring in proximity to commercially managed groves. | huanglongbing is one of the most devastating diseases of citrus (citrus spp.). one management tactic against huanglongbing is aggressive management of the vector, the asian citrus psyllid (diaphorina citri kuwayama), with insecticide applications. however, d. citri in abandoned groves are not controlled and therefore pose a risk of reinfestation for nearby commercial citrus. these abandoned groves could serve as a reservoir for the vector, as well as a source of the presumed causal agent for hua ... | 2010 | 21309215 |
| diversity of endosymbionts in the potato psyllid, bactericera cockerelli (triozidae), vector of zebra chip disease of potato. | zebra chip disease is an emerging, serious disease of solanaceous crops and the causal agent is a bacterium "candidatus liberibacter solanacearum" (cls), also known as "candidatus liberibacter psyllaurous", which is transmitted by the potato psyllid, bactericera cockerelli (šulc). we performed bacterial tag-encoded flx amplicon pyrosequencing (btefap) of the 16s rdna genes to determine the bacterial microbiota in adult insects from cls-uninfected and cls-infected strains of b. cockerelli and pot ... | 2011 | 21327558 |
| repellency of a kaolin particle film to potato psyllid, bactericera cockerelli (hemiptera: psyllidae), on tomato under laboratory and field conditions. | the potato psyllid, bactericera cockerelli, is a vector of candidatus liberibacter solanacearum, causing several diseases in solanaceous crops. laboratory and field no-choice and choice experiments were conducted to evaluate the repellency of kaolin particle film on adults of b. cockerelli on tomato plants that had been sprayed with kaolin particle film on the upper surface only, on the lower surface only and on both leaf surfaces. | 2011 | 21337676 |
| effects of insecticides on behavior of adult bactericera cockerelli (hemiptera: triozidae) and transmission of candidatus liberibacter psyllaurous. | the potato psyllid, bactericera cockerelli (sulc) (hemiptera: triozidae), is a serious pest of potatoes (solanum tuberosum l.) that can cause yield loss by direct feeding on crop plants and by vectoring a bacterial pathogen, candidatus liberibacer psyllaurous. current pest management practices rely on the use of insecticides to control the potato psyllid to lower disease incidences and increase yields. although many studies have focused on the mortality that insecticides can cause on potato psyl ... | 2011 | 21510209 |
| the complete genome sequence of 'candidatus liberibacter solanacearum', the bacterium associated with potato zebra chip disease. | zebra chip (zc) is an emerging plant disease that causes aboveground decline of potato shoots and generally results in unusable tubers. this disease has led to multi-million dollar losses for growers in the central and western united states over the past decade and impacts the livelihood of potato farmers in mexico and new zealand. zc is associated with 'candidatus liberibacter solanacearum', a fastidious alpha-proteobacterium that is transmitted by a phloem-feeding psyllid vector, bactericera c ... | 2011 | 21552483 |
| bacteria causing important diseases of citrus utilise distinct modes of pathogenesis to attack a common host. | in this review, we summarise the current knowledge on three pathogens that exhibit distinct tissue specificity and modes of pathogenesis in citrus plants. xanthomonas axonopodis pv. citri causes canker disease and invades the host leaf mesophyll tissue through natural openings and can also survive as an epiphyte. xylella fastidiosa and candidatus liberibacter are vectored by insects and proliferate in the vascular system of the host, either in the phloem (candidatus liberibacter) or xylem (x. fa ... | 2010 | 20449739 |
| chemical characterization of orange juice from trees infected with citrus greening (huanglongbing). | the effects due to candidatus liberibacter infection, commonly called citrus greening or huanglongbing (hlb), on volatile and nonvolatile components of orange juices, oj, were examined using gc-ms and high-performance liquid chromatography (hplc). hlb symptomatic, asymptomatic, and control "hamlin" and "valencia" oranges were harvested from december to may during the 2007 to 2008 harvest season. brix/acid levels in control and asymptomatic juices were similar but symptomatic juices were as much ... | 2010 | 20492226 |
| effect of liberibacter infection (huanglongbing or "greening" disease) of citrus on orange juice flavor quality by sensory evaluation. | some anecdotal reports suggest that infection of citrus trees with candidatus liberibacter asiaticus (las), the suspected causal agent of huanglongbing (hlb) disease, imparts off flavor to orange juice. it is of interest to the industry to know how las infection affects juice quality with respect to cultivar, maturity, or processing method. hamlin, midsweet, and valencia oranges were harvested over 2 y from trees that tested negative (las-) or positive (las+) for las from different groves and in ... | 2010 | 20546425 |
| sulfur volatiles from allium spp. affect asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), response to citrus volatiles. | the asian citrus psyllid, diaphorina citri kuwayama, vectors candidatus liberibacter asiaticus (las) and candidatus liberibacter americanus (lam), the presumed causal agents of huanglongbing. d. citri generally rely on olfaction and vision for detection of host cues. plant volatiles from allium spp. (alliaceae) are known to repel several arthropod species. we examined the effect of garlic chive (a. tuberosum rottl.) and wild onion (a. canadense l.) volatiles on d. citri behaviour in a two-port d ... | 2011 | 20609277 |
| discovery of novel seca inhibitors of candidatus liberibacter asiaticus by structure based design. | candidatus liberibacter asiaticus is the causal agent of huanglongbing (hlb) disease of citrus. current management practices have not been able to control hlb and stop the spread of hlb. the current study is focused on screening small molecule inhibitors against seca protein of ca. l. asiaticus. homology modeling, structure based virtual screening and molecular docking methods have been used to find the novel inhibitory compounds against seca activity at atp binding region. at 20++m 17 compounds ... | 2011 | 21684161 |
| chemical compounds effective against the citrus huanglongbing bacterium 'candidatus liberibacter asiaticus' in planta. | abstract citrus huanglongbing (hlb) is one of the most destructive diseases of citrus worldwide and is threatening the survival of the floridian citrus industry. currently, there is no established cure for this century-old and emerging disease. as a possible control strategy for citrus hlb, therapeutic compounds were screened using a propagation test system with 'candidatus liberibacter asiaticus'-infected periwinkle and citrus plants. the results demonstrated that the combination of penicillin ... | 2011 | 21834727 |
| colonization of citrus seed coats by 'candidatus liberibacter asiaticus': implications for seed transmission of the bacterium. | huanglongbing is an economically damaging disease of citrus associated with infection by 'ca. liberibacter asiaticus'. transmission of the organism via infection of seeds has not been demonstrated but is a concern since some citrus varieties, particularly those used as rootstocks in commercial plantings are propagated from seed. we compared the incidence of detection of 'ca. liberibacter asiaticus' dna in individual fruit peduncles, seed coats, seeds and in germinated seedlings from 'sanguenelli ... | 2011 | 21714779 |
| Callose deposition in the phloem plasmodesmata and inhibition of phloem transport in citrus leaves infected with "Candidatus Liberibacter asiaticus" | Huanglongbing (HLB) is a destructive disease of citrus trees caused by phloem-limited bacteria, Candidatus Liberibacter spp. One of the early microscopic manifestations of HLB is excessive starch accumulation in leaf chloroplasts. We hypothesize that the causative bacteria in the phloem may intervene photoassimilate export, causing the starch to over-accumulate. We examined citrus leaf phloem cells by microscopy methods to characterize plant responses to Liberibacter infection and the contributi ... | 2011 | 21874517 |
| oral delivery of double-stranded rnas and sirnas induces rnai effects in the potato/tomato psyllid, bactericerca cockerelli. | the potato/tomato psyllid, bactericerca cockerelli (b. cockerelli), and the asian citrus psyllid, diaphorina citri (d. citri), are very important plant pests, but they are also vectors of phloem-limited bacteria that are associated with two devastating plant diseases. b. cockerelli is the vector of candidatus liberibacter psyllaurous (solanacearum), which is associated with zebra chip disease of potatoes, and d. citri is the vector of ca. liberibacter asiaticus, which is associated with the huan ... | 2011 | 22110747 |
| Effect of 'Candidatus Liberibacter solanacearum' on Fitness of Its Insect Vector, Bactericera cockerelli (Hemiptera: Triozidae), on Tomato. | ABSTRACT The potato/tomato psyllid, Bactericera cockerelli transmits the bacterium 'Candidatus Liberibacter solanacearum', also known as 'Ca. L. psyllaurous', which causes zebra chip disease in solanaceous crops. There have been no studies addressing the effect of the bacterial plant pathogen on the biology of its insect vector. We examined several life-history traits, including 7-day fecundity, hatching percentage, incubation time, nymphal survival percentage, nymphal development time, total ... | 2012 | 21899387 |
| Vector transmission efficiency of liberibacter by Bactericera cockerelli (Hemiptera: Triozidae) in zebra chip potato disease: effects of psyllid life stage and inoculation access period. | Successful transmission of plant pathogens by insects depends on the vector inoculation efficiency and how rapidly the insect can effectively transmit the pathogen to the host plant. The potato psyllid, Bactericera cockerelli (Sulc), has recently been found to transmit "Candidatus Liberibacter solanacearum," a bacterium associated with zebra chip (ZC), an emerging and economically important disease of potato in several parts of the world. Currently, little is known about the epidemiology of ZC a ... | 2011 | 22066176 |
| comparison of the 'ca. liberibacter asiaticus' genome adapted for an intracellular lifestyle with other members of the rhizobiales. | an intracellular plant pathogen 'candidatus liberibacter asiaticus,' a member of the rhizobiales, is related to sinorhizobium meliloti, bradyrhizobium japonicum, nitrogen fixing endosymbionts, agrobacterium tumefaciens, a plant pathogen, and bartonella henselae, an intracellular mammalian pathogen. whole chromosome comparisons identified at least 50 clusters of conserved orthologous genes found on the chromosomes of all five metabolically diverse species. the intracellular pathogens 'ca. liberib ... | 2011 | 21876745 |
| Characterization of five CYP4 genes from Asian citrus psyllid and their expression levels in Candidatus Liberibacter asiaticus-infected and uninfected psyllids. | Previously, we reported that Candidatus Liberibacter asiaticus (Las)-infected Diaphorina citri are characterized by lower levels of cytochrome P450 monooxygenases than uninfected counterparts. In the present study, we investigated expression levels of family 4 cytochrome P450 (CYP4) genes in Las-infected and uninfected D.citri adults. Five novel CYP4 genes (CYP4C67, CYP4DA1, CYP4C68, CYP4DB1 and CYP4G70) were identified. Four of the five CYP4 genes were expressed at significantly higher levels i ... | 2011 | 21919983 |
| huanglongbing alters the structure and functional diversity of microbial communities associated with citrus rhizosphere. | the diversity and stability of bacterial communities present in the rhizosphere heavily influence soil and plant quality and ecosystem sustainability. the goal of this study is to understand how 'candidatus liberibacter asiaticus' (known to cause huanglongbing, hlb) influences the structure and functional potential of microbial communities associated with the citrus rhizosphere. clone library sequencing and taxon/group-specific quantitative real-time pcr results showed that 'ca. l. asiaticus' in ... | 2011 | 21796220 |
| diversity and plasticity of the intracellular plant pathogen and insect symbiont, 'candidatus liberibacter asiaticus', revealed by hyper variable prophage genes with intragenic tandem repeats. | 'candidatus liberibacter asiaticus' (las) is a psyllid-transmitted, phloem-limited alpha proteobacterium, and the most prevalent species of liberibacter associated with a devastating worldwide citrus disease known as huanglongbing (hlb). two related and hyper variable genes (hyvi and hyvii) were identified in the prophage regions of the psy62 las genome. sequence analyses of the hyvi/hyvii genes in 35 las dna isolates collected globally revealed hyvi gene contains up to12 nearly identical tandem ... | 2011 | 21784907 |
| translocation of "candidatus liberibacter solanacearum", the zebra chip pathogen, in potato and tomato. | zebra chip disease is a serious threat to potato production. the causative agent, the phloem-limited bacterium "candidatus liberibacter solanacearum," is vectored by the potato/tomato psyllid, bactericerca cockerelli, to potato and tomato. patterns of pathogen translocation through phloem in potato and tomato plants were examined to determine whether rate or direction of translocation vary by host species or potato varieties. two insects were given a 7-day inoculation access period on a single l ... | 2011 | 21770778 |