title: A Large Family of AvrLm6-like Genes in the Apple and Pear Scab Pathogens, Venturia inaequalis and Venturia pirina.
abstract: Venturia inaequalis and V. pirina are Dothideomycete fungi that cause apple scab and pear scab disease, respectively. Whole genome sequencing of V. inaequalis and V. pirina isolates has revealed predicted proteins with sequence similarity to AvrLm6, a Leptosphaeria maculans effector that triggers a resistance response in Brassica napus and B. juncea carrying the resistance gene, Rlm6. AvrLm6-like genes are present as large families (>15 members) in all sequenced strains of V. inaequalis and V. pirina, while in L. maculans, only AvrLm6 and a single paralog have been identified. The Venturia AvrLm6-like genes are located in gene-poor regions of the genomes, and mostly in close proximity to transposable elements, which may explain the expansion of these gene families. An AvrLm6-like gene from V. inaequalis with the highest sequence identity to AvrLm6 was unable to trigger a resistance response in Rlm6-carrying B. juncea. RNA-seq and qRT-PCR gene expression analyses, of in planta- and in vitro-grown V. inaequalis, has revealed that many of the AvrLm6-like genes are expressed during infection. An AvrLm6 homolog from V. inaequalis that is up-regulated during infection was shown (using an eYFP-fusion protein construct) to be localized to the sub-cuticular stroma during biotrophic infection of apple hypocotyls.
authors.affiliation: Animal, Plant and Soil Sciences Department, AgriBio, AgriBiosciences Research Centre, La Trobe University, Melbourne VIC, Australia.
authors.forename: Jason
authors.initials: J
authors.lastname: Shiller
authors.affiliation: School of BioSciences, University of Melbourne, Parkville VIC, Australia.
authors.forename: Angela P
authors.initials: AP
authors.lastname: Van de Wouw
authors.affiliation: Animal, Plant and Soil Sciences Department, AgriBio, AgriBiosciences Research Centre, La Trobe University, Melbourne VIC, Australia ; Plant Sciences Division, Research School of Biology, The Australian National University, Canberra ACT, Australia.
authors.forename: Adam P
authors.initials: AP
authors.lastname: Taranto
authors.affiliation: The New Zealand Institute for Plant and Food Research Limited Auckland, New Zealand.
authors.forename: Joanna K
authors.initials: JK
authors.lastname: Bowen
authors.affiliation: School of BioSciences, University of Melbourne, Parkville VIC, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Dubois
authors.affiliation: Animal, Plant and Soil Sciences Department, AgriBio, AgriBiosciences Research Centre, La Trobe University, Melbourne VIC, Australia ; Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative, Melbourne VIC, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Robinson
authors.affiliation: The New Zealand Institute for Plant and Food Research Limited Auckland, New Zealand.
authors.forename: Cecilia H
authors.initials: CH
authors.lastname: Deng
authors.affiliation: Animal, Plant and Soil Sciences Department, AgriBio, AgriBiosciences Research Centre, La Trobe University, Melbourne VIC, Australia.
authors.forename: Kim M
authors.initials: KM
authors.lastname: Plummer
keywords: Dothideomycete; RIP; WGS; effector; gene families