All papers considered have been deposited as pdf files in a shared data storage service provided by the illinois natural history survey university of illinois. Diversity of phytoplasmas infecting fruit trees and their. Phytoplasmas and their interactions with hosts sciencedirect. Vectors still have not yet been identified for about half of the 33 known phytoplasma groups and this has greatly hindered efforts to control the spread of diseases affecting important crops.
Diversity, host range, and the impact of farming practices on disease incidence abstract the coconut palm cocos nucifera is a major cash crop that is widely grown in coastal tropical regions of the. For example, japanese hydrangea phyllody jhp phytoplasmas were also observed in phloem tissues of the leaf. Phytoplasmas are plant pathogens that have been recognized in more than 700 host plant species. Insect vectors, primarily leafhoppers, planthoppers, and psyllids, have been identified for relatively few phytoplasma diseases, limiting the capacity of managers to make informed decisions to protect crops and endangered indigenous plants. Phytoplasmas are phloemlimited plant pathogenic bacteria in the class mollicutes. Detection and molecular characterization of phytoplasmas. Notes on taxonomy and nomenclature top of page candidatusphytoplasma asteris is a member of the aster yellows ay phytoplasma group or 16sri group, the largest and most diverse phytoplasma group irpcm, 2004. The tuf gene has been used for 16sri and 16srxii subgroup diversity of phytoplasmas 28, 31. In several comprehensive studies on phylogeny and taxonomy of the phytoplasmas, many phytoplasmas from several phylogenetic groups have. Sequence alignment of the16s ribosomal gene region used for specific amplification and detection of sesame 16sr group ii and ix phytoplasmas with other 16sr group phytoplasmas. Phytoplasmas are phloemlimited plant pathogenic bacteria in the class mollicutes transmitted by. Taxonomy of phytoplasmas associated with emerging diseases assunta bertaccini1 and bojan duduk2 1dista, plant pathology, alma mater studiorum, university of bologna, bologna, italy assunta. Phytoplasmas belong to the monotypic order acholeplasmatales. The probes specific to 16srii and 16srix are indicated in blue and green color, respectively.
This oblige on one hand to search for more accurate. Ecological implications from a molecular analysis of phytoplasmas involved in an aster yellows epidemic in various crops in texas. Recent molecular data on phytoplasmas have provided considerable insights into their diversity and genetic interrelationships that are the basis for several comprehensive studies on phytoplasma phylogeny and taxonomy hogenhout et al. Information on the presence of phytoplasma in bananas as one of the pathogens that can cause disease in bananas in indonesia has never been reported.
They are transmitted by insects belonging to the families. Genomic and evolutionary aspects of phytoplasmas frontiers. Accurate identification, differentiation, and quantification of phyllodycausing phytoplasmas are essential for. Genomic sequencing of these bacteria has revealed their survival strategies and adaptations to parasitism. Novel aspects of grapevine response to phytoplasma. The presence of phytoplasmas in plant and insect samples and their identification was carried out by symptom observations in the field, double antibody sandwichenzyme linked immunosorbent assay daselisa, nested polymerase chain reaction nestedpcr and restriction fragment length polymorphism rflp analyses.
Outlook about persepectives and future work to contain spread of these diseases are also reported. Multiplex realtime qpcr assay for simultaneous and. Phytoplasmas associated with ash decline arizona state. An online global database of hemipteraphytoplasmaplant. Abstract plant diseases caused by, or associated with, phytoplasmas occur in hundreds of commercial and native plants, causing minor to extensive damage. Taxonomy based on 16s ribosomal gene, is it enough. B, and d subgroup pytoplasmas were tested againstcrotalaria witches broom phytoplasmas and no pcr product was amplified, which suggests that the sap11 ofcrotalaria phytoplasma is different from the sap11 of the other phytoplasmas. Novel aspects of grapevine response to phytoplasma infection investigated by a proteomic and. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. These plant pathogens are prokaryotes belonging to the mollicutes class since they lack a cell wall.
Phytoplasmas are cell wallless prokaryotic pathogens causing many plant diseases with various host plants, widely geographical distribution and adverse impacts on economics and environments. The complete genomic sequences of four candidatus phytoplasma species have. Revised classification scheme of phytoplasmas based on. If possible, please send us both the literature citation once published and a reprint or pdf file of the publication. Palm yellows phytoplasmas and their genetic classification. Identification of molecular markers to follow insect vector population distribution, particularly for fruit tree phytoplasmas, was also achieved. Ecological implications from a molecular analysis of. Elimination of phytoplasmas in rubus mother plants by tissue culture. Overlapping plant hosts and vectors also give ample opportunities for phytoplasmas to interact and exchange genetic information. On the basis of 16s rrna gene sequence analysis, the ay phytoplasma group is relatively homogeneous, differing in not more than 3% of the nucleotide positions lee et. Current status and perspectives of phytoplasma disease. Phytoplasmas are a worldwide issue in plant health. Novel aspects of grapevine response to phytoplasma infection investigated by a proteomic and phosphoproteomic approach with data integration into functional networks. Parasitic bacteria that infect eukaryotes, such as animals and plants, often have reduced genomes, having lost important metabolic genes as a result of their hostdependent life cycles.
Cost school on bioinformatical analyses of phytoplasma sequences. Classification of a new phytoplasmas subgroup 16sriiw associated. A range of serious diseases are caused by these bacteria in major crops around the globe. Candidatus phytoplasma graminis and candidatus phytoplasma caricae, two novel phytoplasmas associated with diseases of sugarcane, weeds. Plants infected with phytoplasmas exhibit symptoms suggesting a profound disturbance in the normal balance of growth regulators, leading to.
Genetic diversity among phytoplasmas infecting opuntia species. Davis, jonathan shao, ingming lee, wei wei, and yan zhao. Witchs broom disease of lime candidatus phytoplasma. Phytoplasma associated diseases are spread worldwide, and in several cases are associated with severe epidemic of very often quarantine importance. All papers considered have been deposited as pdf files in a shared data storage service provided by the illinois natural history survey. Genetic diversity in the 16srv group and origin of flavescence doree phytoplasma history until 2007. Epidemiology and diagnosis of potato phytoplasmas and. Abundant genetic diversity of the phytoplasmas has been evidenced by vast researches. The combination of specific primers for the sap11 gene of 16sriia. Description this book tries to examine all aspects related to phytoplasmas, their plant hosts and insect vectors. These cellwall lacking bacteria and members of the class mollicutes inhabit plant phloem sieve elements and are transmitted and spread primarily by leafhoppers, plant hoppers and psyllids that feed on infected plants phloem.
Established phytoplasma markers and their contribution to the taxonomy. In recent years, emerging phytoplasma diseases of potato have become increasingly important in many potatoproducing areas around the world. Diagnosis, transmission, and management of phytoplasmas. Please retain photo credits on pictures used from this site. Current status and perspectives of phytoplasma disease research and management cost action fa0807. Later, the icsb subcommittee on the taxonomy of mollicutes 1995 agreed that the phytoplasmas could be assigned a provisional taxonomic status of candidatus, since they could only be defined on the basis of habitat, morphol. Biological sciences bar codes biological diversity epidemiology feed industry. Goals objectives the goals of this research project are to gain a better understanding of the phytoplasmas that infect palms, both from a scientific standpoint but also from an applied standpoint, the biology of their associated vectors,expand the understanding of vector specificity and ultimately reduce economic losses. Salar p, filippin l, carle p, angelini e, foissac x. N2 the epidemiology and etiology of a disease of fraxinus velutina arizona or velvet ash called ash decline was investigated, symptoms of ash decline include a progressive dieback of stems and branches as well as yellowing and necrosis of leaf tissue. By knowing diversity of phytoplasmas that infect palms. Molecular epidemiology and diversity investigations confirmed considerable diversity of both phytoplasmas.
Leaf and twig samples from 32 commercial orchards located in all major fruit growing regions of croatia, were visually inspected for symptoms and tested for the presence of the phytoplasma 16s rdna as were adjacent symptomless. The analysis of particularly ribosomal dna rdna by the sequence or their restriction fragment length polymorphism has provided the basis for phytoplasma taxonomy. Phytoplasmas substantially undistinguishable on 16s rdna gene can be associated with diseases inducing different symptoms andor affecting different plant species, but different phytoplasmas can be associated with similar symptoms in the same or in different plant hosts. Phytoplasmas class mollicutes, genus candidatus phytoplasma are intracellular bacterial. Phytoplasmainfected plants with symptoms of general yellowing, stunting, little leaves, white leaves, virescence, phyllody and witches broom growth of axillary shoots were collected from various plant species in myanmar during 2010 and 2011. Phytoplasma is known to be associated with plant diseases in about 300 plant species from various families. Sequence regions of the primers designed in this study are shown in red color.
An important parameter for the epidemiology of phytoplasma diseases is the wide host range of some phytoplasmas. This book presents research on phytoplasmas, covering their biology, taxonomy and genomics as well as their interactions with. Genetic diversity of phytoplasmas identified in peach. In the spring of 2000, an aster yellows ay epidemic occurred in carrot crops in the winter garden region of. Detection, identification, and significance of phytoplasmas in wild. The opening chapter is followed by chapters on sequencing and functional genomics, which relies heavily on comparing phytoplasma genomics with that of other known bacteria. Phytoplasmas and phytoplasma disease management cost. Candidatus phytoplasma asteris yellow disease phytoplasmas. An online global database of hemiptera phytoplasmaplant. Taxonomy and general characteristics of phytoplasmas phytoplasmas belong to the super kingdom prokaryota, the kingdom monera, the domain bacteria, the phylum firmicutes, the class mollicutes and the candidatus genus phytoplasma. Genetic diversity of european phytoplasmas of the 16srv taxonomic group and.
However, the molecular mechanisms of such malformations in floral organs induced by. The distribution of phytoplasmas in myanmar win 2012. The leafhoppers cicadellidae are a diverse and cosmopolitan group of hemiptera that feed on plants, and occasionally cause losses due to the direct damage they inflict to their hosts, or by transmission of viruses and phytoplasmas. A network for insect vector identification to increase the knowledge about phytoplasma disease epidemiology.
Phytoplasmas are plant pathogenic bacteria that can adversely affect many plant families. In 1992, the subcommittee on the taxonomy of mollicutes proposed the use of phytoplasma rather than mycoplasmalike organisms for reference to the phytopathogenic mollicutes. Several economically relevant phytoplasma associated diseases are described together with an update of phytoplasma taxonomy and major biological and molecular features of phytoplasmas. Classification of a new phytoplasmas subgroup 16sriiw. Phytoplasmas are phloemlimited plant pathogenic bacteria in the class mollicutes transmitted by sapfeeding insect vectors of the order hemiptera. Phyllody, a destructive and economically important disease worldwide caused by phytoplasma infections, is characterized by the abnormal development of floral structures into stunted leafy parts and contributes to serious losses in crop plants, including sesame sesamum indicum l. Sequence analysis of 16s rdna have shown that phytoplasmas constitute.
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