Fig. 6: Natural variants of BnaA07.MKK9 are associated with Sclerotinia stem rot (SSR) resistance in oilseed rape.

a Haplotype analysis of BnaA07.MKK9 based on the BnIR database (https://yanglab.hzau.edu.cn/BnIR). Top: gene structure and DNA polymorphism of BnaA07.MKK9, with exons shown as blue boxes. Bottom: schematic diagram of amino acid motifs. ATP-binding site and phosphorylation sites were predicted with the InterPro database (https://www.ebi.ac.uk/interpro/). b SSR resistance of three haplotypes among 322 oilseed rape accessions in 2016. c SSR resistance of 30 randomly selected accessions for each haplotype in 2021. The violin plots in (b, c) show the median (the solid line in the middle) and the lower and upper quartiles (the dashed lines). The shape of the violin plots represents data distribution, and the bounds indicate the minima and maxima. Statistical significance was determined by a two-tailed Student’s t-test. d Kinase activity of BnaA07.MKK9 in each haplotype in S. sclerotiorum and mock-inoculated leaves analyzed by the immunoprecipitation (IP) kinase assay using myelin basic protein (MBP) as substrate. Values indicate the relative band density of phosphorylated MBP normalized to MBP protein concentration using ImageJ. Molecular mass markers in kilodaltons are shown on the left. For each haplotype, samples were pooled from 10 randomly selected oilseed rape accessions. e Differences in H₂O₂ accumulation induced by the three haplotypes, after their transient expression in N. benthamiana leaves at 12, 24, and 36 h post-transfection (hpf), respectively. Scale bar: 1 cm; EV empty vector. f Variation in haplotype frequency among different ecotypes. g Geographic distribution of the three haplotypes. The global map was generated using the map data function in ggplot2 packages in R (v 4.3.2). For (f, g) 2311 core oilseed rape accessions from the BnIR database were analyzed. h The frequency of haplotypes in 418 accessions from different breeding periods. The green lightning symbol represents introgression from erucic-acid-free and low-glucosinolate (GS) varieties. In (d, e), experiments were repeated three times with similar results. Source data are provided as a Source Data file.