Comparative analysis of the predicted secretomes of Rosaceae scab pathogens Venturia inaequalis and V. pirina reveals expanded effector families and putative determinants of host range

BMC Genomics

Research Article

Patrick Kastner¹  Nathan E. Hall²  Andrew J. Robinson²  Kim M. Plummer³  Adam P. Taranto⁴  Jason Shiller⁵  Darcy A. B. Jones⁶  Cecilia H. Deng⁷  Joanna K. Bowen⁷  Matthew D. Templeton⁸  Carl H. Mesarich⁹ 

[1] Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria, Australia;Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria, Australia;Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative (VLSCI), Victoria, Australia;Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria, Australia;Plant Biosecurity Cooperative Research Centre, Bruce, ACT, Australia;Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria, Australia;Plant Sciences Division, Research School of Biology, The Australian National University, Canberra, Australia;Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria, Australia;Present Address: INRA-Angers, Beaucouzé, Cedex, France;Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria, Australia;Present Address: The Centre for Crop and Disease Management, Curtin University, Bentley, Australia;The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand;The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand;The School of Biological Sciences, University of Auckland, Auckland, New Zealand;The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand;The School of Biological Sciences, University of Auckland, Auckland, New Zealand;Present Address: Institute of Agriculture & Environment, Massey University, Palmerston North, New Zealand;

关键词: Venturia inaequalis;    Venturia pirina;    Apple;    Malus;    European pear;    Pyrus communis;    Secretome;    Effector;   

DOI  :  10.1186/s12864-017-3699-1

 received in 2016-12-09, accepted in 2017-04-11,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundFungal plant pathogens belonging to the genus Venturia cause damaging scab diseases of members of the Rosaceae. In terms of economic impact, the most important of these are V. inaequalis, which infects apple, and V. pirina, which is a pathogen of European pear. Given that Venturia fungi colonise the sub-cuticular space without penetrating plant cells, it is assumed that effectors that contribute to virulence and determination of host range will be secreted into this plant-pathogen interface. Thus the predicted secretomes of a range of isolates of Venturia with distinct host-ranges were interrogated to reveal putative proteins involved in virulence and pathogenicity.ResultsGenomes of Venturia pirina (one European pear scab isolate) and Venturia inaequalis (three apple scab, and one loquat scab, isolates) were sequenced and the predicted secretomes of each isolate identified. RNA-Seq was conducted on the apple-specific V. inaequalis isolate Vi1 (in vitro and infected apple leaves) to highlight virulence and pathogenicity components of the secretome. Genes encoding over 600 small secreted proteins (candidate effectors) were identified, most of which are novel to Venturia, with expansion of putative effector families a feature of the genus. Numerous genes with similarity to Leptosphaeria maculans AvrLm6 and the Verticillium spp. Ave1 were identified. Candidates for avirulence effectors with cognate resistance genes involved in race-cultivar specificity were identified, as were putative proteins involved in host-species determination. Candidate effectors were found, on average, to be in regions of relatively low gene-density and in closer proximity to repeats (e.g. transposable elements), compared with core eukaryotic genes.ConclusionsComparative secretomics has revealed candidate effectors from Venturia fungal plant pathogens that attack pome fruit. Effectors that are putative determinants of host range were identified; both those that may be involved in race-cultivar and host-species specificity. Since many of the effector candidates are in close proximity to repetitive sequences this may point to a possible mechanism for the effector gene family expansion observed and a route to diversification via transposition and repeat-induced point mutation.

【 授权许可】

CC BY   
© The New Zealand Institute for Plant and Food Research Limited. 2017