Year-end Sale % OFF 
Abstract
A virulent strain of Pseudomonas syringae actinidae has invaded kiwifruit (genus Actinidia) orchards in New Zealand, making the study of Actinidia resistance genes critical. Examination of expressed sequence tag (EST) libraries constructed in various species of Actinidia showed that, based on homologies to Arabidopsis, many families of resistance genes were represented. The mapping of these genes to establish their chromosomal positions on the Actinidia chinensis genetic linkage map was facilitated by designing 71 primer pairs to the EST sequences. The genetic markers mapped across 22 of the linkage groups, both as individuals and as members of a cluster. The clusters were generally homologous in nature, though heterologous examples were present. A sample of genes representing both the basal defence and the resistance-gene mediated defence pathways, here termed collectively ‘resistance genes’, was characterised. Chromosomal sites of resistance gene markers representing a range of such genes have been identified and can be considered during the selection of parents in breeding programmes.
Highlights
Plants are under constant attack by various potentially pathogenic microbes
We identified a set of 71 putative defence-resistance genes from an extensive Actinidia expressed sequence tag (EST) database through comparison with the characterised Arabidopsis database
This result may reflect the fact that only a small number of putative resistance gene markers were tested, and/or that some of the linkage groups of the genetic map do not carry as many markers
Summary
Plants are under constant attack by various potentially pathogenic microbes. To counter this offensive, plants have developed detection and response systems that identify pathogen signals and initiate appropriate defences. Studies among accessions of the model plant Arabidopsis found that the plants showed variation in disease resistance and susceptibility when inoculated with different strains of the bacterial pathogen Pseudomonas syringae (Dong et al 1991; Whalen et al 1991; Dangl et al 1992). Some of this variation was the result of recognition of products of the specific bacterial avirulence genes avrRpt and avrRpm, which allowed the plant to restrict the growth of an otherwise virulent P. syringae strain.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
