Dataset Information

The Myrtle rust pathogen, Puccinia psidii, discovered in Africa.

ABSTRACT: Puccinia psidii, the cause of a disease today commonly referred to as Myrtle rust, is considered a high priority quarantine threat globally. It has a wide host range in the Myrtaceae and it is feared that it may result in significant damage to native ecosystems where these plants occur. The fungus is also of considerable concern to plantation forestry industries that propagate Australian Eucalyptus species. In May 2013, symptoms of a rust disease resembling those of P. psidii were observed on an ornamental Myrtaceous shrub in a garden in South Africa. The fungus was identified based on DNA sequence data of the ITS and 5.8S nrRNA gene regions and here we report, for the first time, the presence of P. psidii in Africa.

SUBMITTER: Roux J

PROVIDER: S-EPMC3719202 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The Myrtle rust pathogen, Puccinia psidii, discovered in Africa.

Roux Jolanda J Greyling Izette I Coutinho Teresa A TA Verleur Marcel M Wingfield Michael J MJ

IMA fungus 20130624 1

Puccinia psidii, the cause of a disease today commonly referred to as Myrtle rust, is considered a high priority quarantine threat globally. It has a wide host range in the Myrtaceae and it is feared that it may result in significant damage to native ecosystems where these plants occur. The fungus is also of considerable concern to plantation forestry industries that propagate Australian Eucalyptus species. In May 2013, symptoms of a rust disease resembling those of P. psidii were observed on an ...[more]

PMID: 23898420

Similar Datasets

Project description:The exotic rust fungus Puccinia psidii sensu lato was first detected in Australia in April 2010. This study aimed to determine the host-range potential of this accession of the rust by testing its pathogenicity on plants of 122 taxa, representative of the 15 tribes of the subfamily Myrtoideae in the family Myrtaceae. Each taxon was tested in two separate trials (unless indicated otherwise) that comprised up to five replicates per taxon and six replicates of a positive control (Syzygium jambos). No visible symptoms were observed on the following four taxa in either trial: Eucalyptus grandis×camaldulensis, E. moluccana, Lophostemon confertus and Sannantha angusta. Only small chlorotic or necrotic flecks without any uredinia (rust fruiting bodies) were observed on inoculated leaves of seven other taxa (Acca sellowiana, Corymbia calophylla 'Rosea', Lophostemon suaveolens, Psidium cattleyanum, P. guajava 'Hawaiian' and 'Indian', Syzygium unipunctatum). Fully-developed uredinia were observed on all replicates across both trials of 28 taxa from 8 tribes belonging to the following 17 genera: Agonis, Austromyrtus, Beaufortia, Callistemon, Calothamnus, Chamelaucium, Darwinia, Eucalyptus, Gossia, Kunzea, Leptospermum, Melaleuca, Metrosideros, Syzygium, Thryptomene, Tristania, Verticordia. In contrast, the remaining 83 taxa inoculated, including the majority of Corymbia and Eucalyptus species, developed a broad range of symptoms, often across the full spectrum, from fully-developed uredinia to no visible symptoms. These results were encouraging as they indicate that some levels of genetic resistance to the rust possibly exist in these taxa. Overall, our results indicated no apparent association between the presence or absence of disease symptoms and the phylogenetic relatedness of taxa. It is most likely that the majority of the thousands of Myrtaceae species found in Australia have the potential to become infected to some degree by the rust, although this wide host range may not be fully realized in the field.

Project description:Inoculation of wheat plants with Puccinia triticina (Pt) spores activates a wide range of host responses. Compatible Pt interaction with susceptible Thatcher plants supports all stages of the pathogen life cycle. Incompatible interaction with TcLr9 activates defense responses including oxidative burst and micronecrotic reactions associated with the pathogen's infection structures and leads to complete termination of pathogen development. These two contrasting host-pathogen interactions were a foundation for transcriptome analysis of incompatible wheat-Pt interaction.A suppression subtractive hybridization (SSH) library was constructed using cDNA from pathogen-inoculated susceptible Thatcher and resistant TcLr9 isogenic lines. cDNA represented steps of wheat-brown rust interactions: spore germination, haustorium mother cell (HMC) formation and micronecrotic reactions. All ESTs were clustered and validated by similarity search to wheat genome using BLASTn and sim4db tools. qRT-PCR was used to determine transcript levels of selected ESTs after inoculation in both lines.Out of 793 isolated cDNA clones, 183 were classified into 152 contigs. 89 cDNA clones and encoded proteins were functionally annotated and assigned to 5 Gene Ontology categories: catalytic activity 48 clones (54 %), binding 32 clones (36 %), transporter activity 6 clones (7 %), structural molecule activity 2 clones (2 %) and molecular transducer activity 1 clone (1 %). Detailed expression profiles of 8 selected clones were analyzed using the same plant-pathogen system. The strongest induction after pathogen infection and the biggest differences between resistant and susceptible interactions were detected for clones encoding wall-associated kinase (GenBank accession number JG969003), receptor with leucine-rich repeat domain (JG968955), putative serine/threonine protein kinase (JG968944), calcium-mediated signaling protein (JG968925) and 14-3-3 protein (JG968969).The SSH library represents transcripts regulated by pathogen infection during compatible and incompatible interactions of wheat with P. triticina. Annotation of selected clones confirms their putative roles in successive steps of plant-pathogen interactions. The transcripts can be categorized as defense-related due to their involvement in either basal defense or resistance through an R-gene mediated reaction. The possible involvement of selected clones in pathogen recognition and pathogen-induced signaling as well as resistance mechanisms such as cell wall enforcement, oxidative burst and micronecrotic reactions is discussed.

Dataset Information

The Myrtle rust pathogen, Puccinia psidii, discovered in Africa.

Publications

The Myrtle rust pathogen, Puccinia psidii, discovered in Africa.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets