Genetic diversity of phytoplasmas identified in peach. Novel aspects of grapevine response to phytoplasma infection investigated by a proteomic and. 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. 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. Classification of a new phytoplasmas subgroup 16sriiw associated. Phytoplasmas were discovered almost 50 years ago and initially they were named mycoplasmalike organisms. 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. Cost school on bioinformatical analyses of phytoplasma sequences. 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. Identification of molecular markers to follow insect vector population distribution, particularly for fruit tree phytoplasmas, was also achieved. 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. Phytoplasmas belong to the monotypic order acholeplasmatales. Candidatus phytoplasma graminis and candidatus phytoplasma caricae, two novel phytoplasmas associated with diseases of sugarcane, weeds.
Diagnosis, transmission, and management of phytoplasmas. The tuf gene has been used for 16sri and 16srxii subgroup diversity of phytoplasmas 28, 31. Taxonomy of phytoplasmas associated with emerging diseases assunta bertaccini1 and bojan duduk2 1dista, plant pathology, alma mater studiorum, university of bologna, bologna, italy assunta. Abundant genetic diversity of the phytoplasmas has been evidenced by vast researches. Overlapping plant hosts and vectors also give ample opportunities for phytoplasmas to interact and exchange genetic information. Sequence analysis of 16s rdna have shown that phytoplasmas constitute. Detection, identification, and significance of phytoplasmas in wild.
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. If possible, please send us both the literature citation once published and a reprint or pdf file of the publication. Phytoplasma associated diseases are spread worldwide, and in several cases are associated with severe epidemic of very often quarantine importance. 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. 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. Phytoplasmas are phloemlimited plant pathogenic bacteria in the class mollicutes transmitted by sapfeeding insect vectors of the order hemiptera. 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. Phytoplasmas are plant pathogenic bacteria that can adversely affect many plant families. Current status and perspectives of phytoplasma disease. Genetic diversity in the 16srv group and origin of flavescence doree phytoplasma history until 2007. Molecular epidemiology and diversity investigations confirmed considerable diversity of both phytoplasmas. Epidemiology and diagnosis of potato phytoplasmas and.
A range of serious diseases are caused by these bacteria in major crops around the globe. 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. 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 a worldwide issue in plant health. In several comprehensive studies on phylogeny and taxonomy of the phytoplasmas, many phytoplasmas from several phylogenetic groups have.
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. Please retain photo credits on pictures used from this site. 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. Description this book tries to examine all aspects related to phytoplasmas, their plant hosts and insect vectors. Detection and molecular characterization of phytoplasmas. An important parameter for the epidemiology of phytoplasma diseases is the wide host range of some phytoplasmas. All papers considered have been deposited as pdf files in a shared data storage service provided by the illinois natural history survey. Ecological implications from a molecular analysis of. Genetic diversity of european phytoplasmas of the 16srv taxonomic group and. 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. Candidatus phytoplasma asteris yellow disease phytoplasmas. Phytoplasmas are cell wallless prokaryotic pathogens causing many plant diseases with various host plants, widely geographical distribution and adverse impacts on economics and environments. An online global database of hemiptera phytoplasmaplant.
Witchs broom disease of lime candidatus phytoplasma. A network for insect vector identification to increase the knowledge about phytoplasma disease epidemiology. Genomic sequencing of these bacteria has revealed their survival strategies and adaptations to parasitism. In the spring of 2000, an aster yellows ay epidemic occurred in carrot crops in the winter garden region of. Taxonomy based on 16s ribosomal gene, is it enough. Sequence regions of the primers designed in this study are shown in red color. Palm yellows phytoplasmas and their genetic classification. They are transmitted by insects belonging to the families. By knowing diversity of phytoplasmas that infect palms. Phytoplasma is known to be associated with plant diseases in about 300 plant species from various families. 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 among phytoplasmas infecting opuntia species. In recent years, emerging phytoplasma diseases of potato have become increasingly important in many potatoproducing areas around the world. An online global database of hemipteraphytoplasmaplant.
Phytoplasmas are phloemlimited plant pathogenic bacteria in the class mollicutes transmitted by. The distribution of phytoplasmas in myanmar win 2012. 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. Elimination of phytoplasmas in rubus mother plants by tissue culture. 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. 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. Phytoplasmas are phloemlimited plant pathogenic bacteria in the class mollicutes.
Revised classification scheme of phytoplasmas based on. The analysis of particularly ribosomal dna rdna by the sequence or their restriction fragment length polymorphism has provided the basis for phytoplasma taxonomy. Davis, jonathan shao, ingming lee, wei wei, and yan zhao. These plant pathogens are prokaryotes belonging to the mollicutes class since they lack a cell wall. 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. Novel aspects of grapevine response to phytoplasma infection investigated by a proteomic and phosphoproteomic approach with data integration into functional networks. Abstract plant diseases caused by, or associated with, phytoplasmas occur in hundreds of commercial and native plants, causing minor to extensive damage. 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. However, the molecular mechanisms of such malformations in floral organs induced by. Phytoplasmas and their interactions with hosts sciencedirect.
In 1992, the subcommittee on the taxonomy of mollicutes proposed the use of phytoplasma rather than mycoplasmalike organisms for reference to the phytopathogenic mollicutes. 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. This book presents research on phytoplasmas, covering their biology, taxonomy and genomics as well as their interactions with. Classification of a new phytoplasmas subgroup 16sriiw. The combination of specific primers for the sap11 gene of 16sriia. Established phytoplasma markers and their contribution to the taxonomy.
Several economically relevant phytoplasma associated diseases are described together with an update of phytoplasma taxonomy and major biological and molecular features of phytoplasmas. Multiplex realtime qpcr assay for simultaneous and. The complete genomic sequences of four candidatus phytoplasma species have. Phytoplasmas class mollicutes, genus candidatus phytoplasma are intracellular bacterial. Phytoplasmas are plant pathogens that have been recognized in more than 700 host plant species.
Biological sciences bar codes biological diversity epidemiology feed industry. Genomic and evolutionary aspects of phytoplasmas frontiers. For example, japanese hydrangea phyllody jhp phytoplasmas were also observed in phloem tissues of the leaf. The probes specific to 16srii and 16srix are indicated in blue and green color, respectively. 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. 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. Plants infected with phytoplasmas exhibit symptoms suggesting a profound disturbance in the normal balance of growth regulators, leading to. Current status and perspectives of phytoplasma disease research and management cost action fa0807. Outlook about persepectives and future work to contain spread of these diseases are also reported. Accurate identification, differentiation, and quantification of phyllodycausing phytoplasmas are essential for. Coconut lethal yellowing phytoplasma disease in mozambique. Novel aspects of grapevine response to phytoplasma. Ecological implications from a molecular analysis of phytoplasmas involved in an aster yellows epidemic in various crops in texas. Diversity of phytoplasmas infecting fruit trees and their.
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