Fig. 1: GhDP1_A1 and GhDP1_A2 function as derailers of the gossypol pathway to enable the production of hemigossypolone and heliocides in cotton green organs.
a Proposed biosynthetic pathways of 3, 4, and 5a ~ 5d in cotton. FPP from the MVA pathway is converted into 1 through CDN, P450s, dioxygenases, etc. 1 can either undergo homocoupling to form 4 or be further hydroxylated to produce 3. Previous studies suggest that 3 may originate from deoxyhemigossypol84,85,86,87. 3 and MEP-derived monoterpenes undergo a Diels-Alder reaction to yield 5a ~ 5d. Solid lines, well-characterized steps; Dashed lines, putative steps. b Heatmap of relative abundance of compounds 3 and 4 across various cotton organs. Ratios of 3 to 4 were calculated and log2-transformed. Color gradient, relative abundance (red: 3-dominant; yellow: 4-dominant). Detailed quantitative data in Supplementary Data 1. c Correlation network of 3 levels and the transcript abundance of glandular-specific genes across eight cotton organs. Only genes with P ≤ 0.05 (two-tailed) are included. Edge thickness, correlation magnitude; Node size, -log10(P_value) value; Blue node, compound 3; Red node, GhDP1_A1 and GhDP1_A2; Orange node, known terpenoid biosynthesis genes; Gray node, other significantly correlated but uncharacterized genes. Transcript data analyzed with edgeR; correlations and P values calculated using rcorr in R (Detailed in Supplementary Data 2). d Heatmap illustrating 3 accumulation patterns and organ-specific transcript abundance of GhDP1_A1, GhDP1_A2, and other 4 biosynthetic genes. The FPKM values were normalized by log2 transformation and then used to generate the heatmap. e Dot plots depicting the expression profiles of GhDP1_A1 and GhDP1_A2 across various cell types in cotton leaves. Dot color, scaled expression; Dot size, proportion of cells within each cluster that express the corresponding gene. f GUS staining analysis of wild-type, pGhDP1_A1::GUS and pGhDP1_A2::GUS cotton leaves. Scale bars, 50 μm. g Confocal microscopy images of wild-type and transgenic cotton leaves expressing pGhDP1_A1::GhDP1_A1-GFP and pGhDP1_A2::GhDP1_A2-GFP. Scale bar, 30 μm. For f–g the experiments were independently repeated three times with similar results. h Phylogenetic analysis of AtDIRs alongside functionally characterized dirigent proteins. Functionally characterized proteins are marked with yellow asterisks. Source data are provided as a Source Data file.
