Extended Data Fig. 5: Association of DRESH8 with kernel length of the maize panel and the expression levels of four negative regulators of seed development.

a. Comparison of kernel length (KL) between maize inbred lines with DRESH8 (DRESH8^+/+) and those without DRESH8 (DRESH8^−/−) under well-watered conditions. Values indicate means ± s.d. and the P values were calculated by two-sided Student’s t-test from ears with DRESH8^+/+ (N = 57) and DRESH8^−/− (N = 318) in the association panel used in the comparison. b–e. Expression of ZmARF2 (b), ZmRPT2A (c), ZmDA2 (d) and ZmHK4 (e), which were involved in kernel development, in maize inbred accessions with (+, N = 37) or without (−, N = 160) DRESH8. The genes ZmARF2, ZmRPT2A, ZmDA2, and ZmHK4 were previously reported to play negative roles during seed development¹⁶. The expression data are from RNA-seq of 197 maize inbred accessions grown under WW or DS conditions. Box middle line: median; box edges: 25th and 75th percentiles; whiskers: values that do not exceed ± IQR (interquartile range) × 1.5; further outliers are marked individually. The P values were calculated by two-sided Student’s t-test. f–i. Expression of ZmARF2 (f), ZmRPT2A (g), ZmDA2 (h) and ZmHK4 (i) in transgenic dDRESH8 plants and the nontransgenic B104 plants. Values indicate means ± s.d. and the P values were calculated by two-sided Student’s t-test from different technical repeats in f (N = 6 for dDRESH8, 5 for B104), g (N = 3 for dDRESH8, 5 for B104), h (N = 8 for dDRESH8, 6 for B104), i (N = 5 for both dDRESH8 and B104). The experiments were repeated three times and similar results were obtained.