Overexpression of SiICE2 gene reduces plant height and increases yield in cotton (Gossypium hirsutum).

Cotton (Gossypium hirsutum) is the predominant global fiber crop and has considerable significance because of its agronomic characteristics. Among these characteristics, plant height plays a vital role in determining harvest index and yield potential. Previous studies have mainly focused on elucidating the mechanisms governing the ICE-CBF-COR cascade to enhance plant resilienceto low temperatures. Although the ICE2 lines did not show cold tolerance, they exhibited dwarfing of the plants and increased yield. This led to the observations of reduced hypocotyl and internode length, increased biomass, higher yield, and shorter fiber length in the ICE2 lines through phenotypic assessment. From the leaf transcriptome analysis, differential expression of the BR synthesis signaling pathway and the CBF1 gene was identified. qRT-PCR analysis revealed upregulation of GhCBF1 and downregulation of GhTCH4 in the stems of the ICE2 lines. Significantly, the application of BL spray led to an increase in cotton plant height, with the ICE2 lines demonstrating the highest elongation rate. In conclusion, the reduction in plant height observed in the ICE2 lines can be ascribed to the integration of the SiICE2 gene influencing the BR signaling pathway and the expression of the CBF1 gene in cotton, which inhibits cell elongation and results in shorter cotton plants. To provide a reference for the optimization of agricultural cotton production.