The DTH8-SD1 pair regulates panicle architecture in rice

Su Su, Jun Hong, Ling Li, Xiaofei Chen, Cai Chen & Jianxin Shi

TAG; February 3 2026; vol. 139; article 56

Abstract

Rice yield-related traits are regulated by numerous quantitative trait loci (QTLs). Pyramiding these QTLs offers a promising strategy for crop yield improvement; however, this approach is constrained by the limited understanding of the interactions among these QTLs. In this study, we demonstrated that the QTL DTH8 significantly increases branch numbers, panicle length, and number of total grains per panicle in rice. Notably, the DTH8⁹³¹¹ allele exhibited a more pronounced effect on enhancing yield-related traits compared to DTH8^Nip. Furthermore, QTL pyramiding involving SD1 and DTH8 indicated that the regulation of panicle architecture by DTH8 partially depends on SD1. Genetic analysis revealed an interaction between these two QTL/genes with respect to panicle-related traits. Dual-luciferase and ChIP-PCR analyses suggested that DTH8 might regulate the expression of SD1, thereby governing branch numbers, panicle length, and number of total grains per panicle. Additionally, our findings highlight the importance of avoiding the simultaneous pyramiding of sd1 and DTH8⁹³¹¹ in practical breeding programs due to their genetic and molecular interactions.

See https://link.springer.com/article/10.1007/s00122-025-05147-9