Fig. 4: GWAS for NLR and functional analysis of HbPSK5.

a Manhattan plot of GWAS for NLR. The black arrowhead indicated a significant signal. b Fine mapping of the region related to NLR. The gray column represented an overlapping region of 20 kb. c Tissue-specific expression of putative genes around the GWAS signal peak. The bar represented FPKM values. d Gene structure of HbPSK5. Red star indicated a significant SNP site. e Relationships of NLR with genotypes GG, GA, and AA among 93 cultivated and 115 wild germplasms. The results are expressed as means ± s.d. in three biological replicates. The number of accessions for each category is shown in figure. P values are calculated with two-sided Student’s t-test. f Distributions of the three genotypes in 127 cultivars and 208 wild germplasms. g Distributions of the three genotypes in offspring with more laticifer rings (ML) and fewer laticifer rings (FL) identified from hybrid separation populations. h The proportions of the three genotypes differed by generation. i Representative light micrographs of bark cross-sections in ten biological replicates, showing the effects of mechanical wounding, H₂O, COR, and PSK on the differentiation of secondary laticifer cells. Red arrowhead, secondary laticifer cells; pink arrowhead, primary laticifer cells; Ca, cambia; R, ray cell; S, sieve tube. Scale bars = 100 μm. j Assays of the transient transcriptional activities of HbMYCs on HbPSK5. The results are expressed as means ± s.d. in sixteen biological replicates. In each box plot, the center line indicates the median, the edges of the box represent the first and third quartiles, and the whiskers extend to span a 1.5 interquartile range from the edges. P values are calculated with two-sided Student’s t-test. k, l Effects of overexpressed HbMYC26 (k) or HbPSK5 (l) on the differentiation of laticifer cells in TKS. The results are expressed as means ± s.d. in three biological replicates. P values are calculated with two-sided Student’s t-test. m, n Effects of overexpressed HbMYC26 (m) or HbPSK5 (n) on the rubber content in TKS. The results are expressed as means ± s.d. in three biological replicates. P values are calculated with two-sided Student’s t-test. Source data are provided as a Source data file.