Fig. 1
OsNR2 allelic variation confers the qCR2, and affects NR active activity and 15NO3- uptake. a ClO3− resistance (CR) QTL analysis of RILs from an indica (9311) × japonica (Nipponbare) cross, performed on seedlings germinated from seeds harvested in Hangzhou or Hainan (see Methods). Major QTLs are shown, with numbers indicating genetic map position (cM) on each chromosome. b Fine mapping of qCR2 with a residual heterozygote line (RHL) F2 population. Using a panel of linked markers (Supplementary Table 2), qCR2 was pin-pointed to a 6.4 kb region (Chr.2, between markers IND2-3 and IND2-5) containing OsNR2. Numbers of recombinants between each marker and qCR2 are shown. OsNR2 structure is shown, black boxes represent exons. c Relative seedling vigor indicates degree of ClO3− resistance (Nipponbare harboring constructs for expression of the 9311 OsNR2 allele driven by the 9311 OsNR2 promoter (OsNR2-9311-1 and OsNR2-9311-2) or of OsNR2 RNAi (OsNR2-RNAi-1 and OsNR2-RNAi-2); see Supplementary Fig. 1). d Leaf OsNR2 mRNA abundance, e leaf NR active activity, f 15NO3− uptake activity of roots exposed to 1.25 mM 15NO3−. Value is mean ± s.d. (n = 3 for d–f). Error bar represents s.d. * and ** respectively indicate least significant differences at the 0.05 and 0.01 probability level compared with Nipponbare. The source data underlying Fig. 1d–f are provided as a Source Data file
