Fig. 6.

Organization of regulatory elements of GhGH3s and their expression in response to phytohormones. a The regulatory region of each GhGH3 gene was analyzed, the numbers indicate the sum of various cis-acting elements response to the same stimuli. b The summary of GhGH3 expression response to treatment with IAA, SA, BL and GA in roots (R) and stems (S). Each orthologous pair from At- and Dt-subgenome of G. hirsutum was designed as a single gene and tested together due to their highly identical sequences. In total, 11 analogue genes standing for 20 GhGH3s were generated and could be divided into 3 subgroups (subgroups 1–3). The expression pattern of 11 analogue genes was detected by qRT-PCR. The relative expression intensity, that is, the ratio of the highest expression level to that of the 0 h control, was allocated into six different grades ranging from suppression shown as black boxes to over 20-fold induction shown as red boxes