Fig. 1

Sketch of expression vector and characterization of transgenic cotton plants overexpressing GhSMT2–1. a Sketch of pBI121-GN-OS. RB and LB is right border and left border of T-DNA region, respectively. NOS-P: NOS promoter; NOS-T: NOS terminator; 35S: CaMV 35S promoter. b GUS staining in cotton leaf discs. c Genotyping of transgenic cotton plants by PCR. A fragment of GhSMT2–1 cDNA was amplified from genomic DNA. M, DNA marker; P, positive control, amplified from a plasmid containing the 35S::GhSMT2–1::NOS-T cassette; N, negative control, amplified from the genomic DNA of a non-transgenic cotton plant; W, blank control, amplified from a sample containing only water. d Relative expression level of the GhSMT2–1 gene in the 10-DPA fibers and leaves of control and transgenic cotton plants. Total RNA was isolated from the 10-DPA fibers and leaves of control plants and transgenic lines. The first strand cDNA (from total RNA) was used as the template for RT-qPCR, using cotton HISTONE3 for normalization of the data. OS-1 to OS-10 represents transgenic plant no. 1 to 10