AUTHOR=Hu Ying , Ren Jie , Peng Zhao , Umana Arnoldo A. , Le Ha , Danilova Tatiana , Fu Junjie , Wang Haiyan , Robertson Alison , Hulbert Scot H. , White Frank F. , Liu Sanzhen 

TITLE=Analysis of Extreme Phenotype Bulk Copy Number Variation (XP-CNV) Identified the Association of rp1 with Resistance to Goss's Wilt of Maize

JOURNAL=Frontiers in Plant Science

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00110

DOI=10.3389/fpls.2018.00110

ISSN=1664-462X

ABSTRACT=<p>Goss's wilt (GW) of maize is caused by the Gram-positive bacterium <italic>Clavibacter michiganensis</italic> subsp. <italic>nebraskensis</italic> (Cmn) and has spread in recent years throughout the Great Plains, posing a threat to production. The genetic basis of plant resistance is unknown. Here, a simple method for quantifying disease symptoms was developed and used to select cohorts of highly resistant and highly susceptible lines known as extreme phenotypes (XP). Copy number variation (CNV) analyses using whole genome sequences of bulked XP revealed 141 genes containing CNV between the two XP groups. The CNV genes include the previously identified common rust resistant locus <italic>rp1</italic>. Multiple <italic>Rp1</italic> accessions with distinct <italic>rp1</italic> haplotypes in an otherwise susceptible accession exhibited hypersensitive responses upon inoculation. GW provides an excellent system for the genetic dissection of diseases caused by closely related subspecies of <italic>C. michiganesis</italic>. Further work will facilitate breeding strategies to control GW and provide needed insight into the resistance mechanism of important related diseases such as bacterial canker of tomato and bacterial ring rot of potato.</p>