(A) The phenylpropanoid biosynthesis pathway in pear that influences the conformation of stone cells in fruit. (Red box) Genes that had detectable expression; (light red shaded ovals) important intermediate compounds in lignin pathway; (green text and arrows) pathways with minor expression; (blue boxes) three important end-product compounds in pear fruit; and green-boxed compound cannot be detected. (B) Transcript ratio distribution of all enzymes related to lignin. Three stages of fruit development (S422, early development; S627, middle development; and S830, near ripening) were assessed. The ratio of S422 and S627 is shown along the x-axis, and the ratio of S830 and S627 is shown along the y-axis. For points, different colors correspond to different enzymes, while different shapes correspond to different conditions of false-discovery rate (FDR) values. Abbreviations of genes involved in phenylpropanoid biosynthesis pathway are as follows: LP, L-phenylalanine; CAN, cinnamic acid; PCA, P-coumaric acid; CA, caffeic acid; FA, ferulic acid; 5HA, 5-hydroxyferulate acid; SA, sinapic acid; CNC, cinnamoyl-CoA; PCC, p-coumaroyl-CoA; CFC, caffeoyl-CoA; FC, feruloyl-CoA; 5HC, 5-hydroxyferuloyl-CoA; SC, sinapoyl-CoA; PCouA, p-coumar aldehyde; CafA, caffeyl aldehyde; ConA, conifer aldehyde; 5HydA, 5-hydroxyconifer aldehyde; SinA, sinapoyl aldehyde; PCAlc, p-coumaryl alcohol; CFAlc, caffeyl alcohol; CNAlc, coniferyl alcohol; 5HydAlc, 5-hydroxyconiferyl alcohol; SinAlc, sinapyl alcohol; PHL, p-hydroxyphenyl lignin; GL, guaiacyl lignin; 5GL, 5-hydroxy-guaiacyl lignin; SL, syringyl lignin; PAL, phenylalanine ammonia-lyase; C4H, trans-cinnamate 4-monooxygenase; 4CL, 4-coumarate-CoA ligase; HCT, shikimate O-hydroxycinnamoyltransferase; C3′H, coumaroylquinate 3′-monooxygenase; COMT, caffeic acid 3-O-methyltransferase; CCOMT, caffeoyl-CoA O-methyltransferase; F5H, ferulate-5-hydroxylase; CCR, cinnamoyl-CoA reductase; CAD, cinnamyl-alcohol dehydrogenase; and POD, peroxidase.
