Open AccessHomoeologous chromosome exchange explains the creation of a QTL affecting soil‐borne pathogen resistance in tobacco
Author(s) -
Shi Rui,
Jin Jing,
Nifong Jessica M.,
Shew David,
Lewis Ramsey S.
Publication year - 2022
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.13693
Subject(s) - biology , quantitative trait locus , genetics , nicotiana tabacum , gene , locus (genetics) , ralstonia solanacearum , phytophthora nicotianae , allele , tobacco mosaic virus , plant disease resistance , transcriptome , pathogen , phytophthora , botany , gene expression , virus
Summary Crop plant partial resistance to plant pathogens controlled by quantitative trait loci (QTL) is desirable in cultivar development programmes because of its increased durability. Mechanisms underlying such resistance are difficult to study. We performed RNA‐seq analyses for tobacco ( Nicotiana tabacum ) nearly isogenic lines (NILs) with and without favourable allele(s) at Phn7.1 , a major QTL influencing partial resistance to the soil‐borne pathogens Phytophthora nicotianae and Ralstonia solanacearum . Based upon combined analyses of transcriptome‐based sequence variation and gene expression profiles, we concluded that allelic variability at the Phn7.1 locus was likely generated from homoeologous exchange, which led to deletion of low‐expressing members of the SAR8.2 gene family and duplication of high‐expressing SAR8.2 genes from a different subgenome of allotetraploid tobacco. The high expression of endogenous Phn7.1 ‐associated SAR8.2 genes was correlated with observed resistance to P . nicotianae . Our findings suggest a role for genomic rearrangements in the generation of favourable genetic variability affecting resistance to pathogens in plants.