Zailong Tian, Baojun Chen, Hongge Li, Xinxin Pei, Yaru Sun, Gaofei Sun, Zhaoe Pan, Panhong Dai, Xu Gao, Xiaoli Geng, Zhen Peng, Yinhua Jia, Daowu Hu, Liru Wang, Baoyin Pang, Ai Zhang, Xiongming Du, Shoupu He

Molecular plantarrow

Doi: 10.1016/j.molp.2024.08.007

Abstract：

Optimal plant height is crucial in modern agriculture, influencing lodging resistance and facilitating mechanized crop production. Upland cotton (Gossypium hirsutum) is the most important fiber crop globally; however, the genetic basis underlying plant height remains largely unexplored. In this study, we conducted a genome-wide association studyto identify a major locus controlling plant height (PH1) in upland cotton. This locus encodes gibberellin 2-oxidase 1A (GhPH1)and features a 1133-bpstructural variation (PAVPH1) located approximately 16 kb upstream. The presence or absence of PAVPH1 influences the expression of GhPH1, thereby affecting plant height. Further analysis revealed that a gibberellin-regulating transcription factor (GhGARF) recognizes and binds to a specific CATTTGmotif in both the GhPH1 promoter and PAVPH1. This interaction downregulates GhPH1, indicating that PAVPH1 functions as a distant upstream silencer. Intriguingly, we found that DWARF53 (D53), a key repressor of the strigolactone (SL) signaling pathway, directly interacts with GhGARF to inhibitits binding to targets. Moreover, we identified a previously unrecognized gibberellin-SL crosstalk mechanism mediated by the GhD53-GhGARF-GhPH1/PAVPH1 module, which is crucial for regulating plant height in upland cotton. These findings shed light on the genetic basis and gene interaction network underlying plant height, providing valuable insights for the development of semi-dwarf cotton varieties through precise modulation of GhPH1 expression.