Fig. 5

Functional interpretation of GWAS for lysophosphatidylethanolamine (LPE) 18:1 content in apple. a Lysolipid contents of apples in the “Ralls Janet” (RS) and “Golden Delicious” (GD) pedigrees. b Manhattan plots of LPE 18:1 content by GWAS. c An unrooted phylogenetic tree for MD12G1057600 and Arabidopsis FAD members. d The firmness of apples in “RS” and “GD” pedigrees. e Correlation analysis (R²) between firmness and LPE 18:1 in domesticated apples. f qRT-PCR analysis of FAD2 transcripts in domesticated fruits with high and low LPE 18:1. g Transient overexpression of FAD2 in apple fruits. h,i The firmness and respiration rate of apples treated with LPE 18:1 during storage. j Nucleotide polymorphisms identified in the promoter and coding sequence of FAD2. k Box plots of LPE 18:1 correlated with identified nucleotide polymorphisms. l Nucleotide polymorphisms in the “RS” and “GD” pedigrees. The data are expressed as mean ± sd. “*” indicates p ≤ 0.05 by t-test. The correlation was evaluated based on the Pearson correlation coefficient