AUTHOR=Van Weymers Pauline S. M. , Baker Katie , Chen Xinwei , Harrower Brian , Cooke David E. L. , Gilroy Eleanor M. , Birch Paul R. J. , Thilliez Gaëtan J. A. , Lees Alison K. , Lynott James S. , Armstrong Miles R. , McKenzie Gaynor , Bryan Glenn J. , Hein Ingo 

TITLE=Utilizing “Omic” Technologies to Identify and Prioritize Novel Sources of Resistance to the Oomycete Pathogen Phytophthora infestans in Potato Germplasm Collections

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00672

DOI=10.3389/fpls.2016.00672

ISSN=1664-462X

ABSTRACT=<p>The greatest threat to potato production world-wide is late blight, caused by the oomycete pathogen <italic>Phytophthora infestans</italic>. A screen of 126 wild diploid <italic>Solanum</italic> accessions from the Commonwealth Potato Collection (CPC) with <italic>P. infestans</italic> isolates belonging to the genotype 13-A2 identified resistances in the species <italic>S. bulbocastanum, S. capsicibaccatum, S. microdontum, S. mochiquense, S. okadae, S. pinnatisectum, S. polyadenium, S. tarijense</italic>, and <italic>S. verrucosum.</italic> Effector-omics, allele mining, and diagnostic RenSeq (dRenSeq) were utilized to investigate the nature of resistances in <italic>S. okadae</italic> accessions. dRenSeq in resistant <italic>S. okadae</italic> accessions 7129, 7625, 3762, and a bulk of 20 resistant progeny confirmed the presence of full-length <italic>Rpi-vnt1.1</italic> under stringent mapping conditions and corroborated allele mining results in the accessions 7129 and 7625 as well as Avr-vnt1 recognition in transient expression assays. In contrast, susceptible <italic>S. okadae</italic> accession 3761 and a bulk of 20 susceptible progeny lacked sequence homology in the 5′ end compared to the functional <italic>Rpi-vnt1.1</italic> gene. Further evaluation of <italic>S. okadae</italic> accessions with <italic>P. infestans</italic> isolates that have a broad spectrum of virulence demonstrated that, although <italic>S. okadae</italic> accessions 7129, 7625, and 7629 contain functional <italic>Rpi-vnt1.1</italic>, they also carry a novel resistance gene. We provide evidence that existing germplasm collections are important sources of novel resistances and that “omic” technologies such as dRenSeq-based genomics and effector-omics are efficacious tools to rapidly explore the diversity within these collections.</p>