title: A comparison of the molecular organization of genomic regions associated with resistance to common bacterial blight in two Phaseolus vulgaris genotypes.
abstract: Resistance to common bacterial blight, caused by Xanthomonas axonopodis pv. phaseoli, in Phaseolus vulgaris is conditioned by several loci on different chromosomes. Previous studies with OAC-Rex, a CBB-resistant, white bean variety of Mesoamerican origin, identified two resistance loci associated with the molecular markers Pv-CTT001 and SU91, on chromosome 4 and 8, respectively. Resistance to CBB is assumed to be derived from an interspecific cross with Phaseolus acutifolius in the pedigree of OAC-Rex. Our current whole genome sequencing effort with OAC-Rex provided the opportunity to compare its genome in the regions associated with CBB resistance with the v1.0 release of the P. vulgaris line G19833, which is a large seeded bean of Andean origin, and (assumed to be) CBB susceptible. In addition, the genomic regions containing SAP6, a marker associated with P. vulgaris-derived CBB-resistance on chromosome 10, were compared. These analyses indicated that gene content was highly conserved between G19833 and OAC-Rex across the regions examined (>80%). However, fifty-nine genes unique to OAC Rex were identified, with resistance gene homologues making up the largest category (10 genes identified). Two unique genes in OAC-Rex located within the SU91 resistance QTL have homology to P. acutifolius ESTs and may be potential sources of CBB resistance. As the genomic sequence assembly of OAC-Rex is completed, we expect that further comparisons between it and the G19833 genome will lead to a greater understanding of CBB resistance in bean.
authors.affiliation: Department of Plant Agriculture, University of Guelph, Guelph ON, Canada.
authors.forename: Gregory
authors.initials: G
authors.lastname: Perry
authors.forename: Claudia
authors.initials: C
authors.lastname: Dinatale
authors.forename: Weilong
authors.initials: W
authors.lastname: Xie
authors.forename: Alireza
authors.initials: A
authors.lastname: Navabi
authors.forename: Yarmilla
authors.initials: Y
authors.lastname: Reinprecht
authors.forename: William
authors.initials: W
authors.lastname: Crosby
authors.forename: Kangfu
authors.initials: K
authors.lastname: Yu
authors.forename: Chun
authors.initials: C
authors.lastname: Shi
authors.forename: K Peter
authors.initials: KP
authors.lastname: Pauls
keywords: common bacterial blight; comparative genomics; disease resistance; next generation sequencing; phaseolus vulgaris