Expression profiles of nine cotton salt-responsive miRNAs and their potential corresponding targets detected by sequencing, stem-loop RT-PCR, and qRT-PCR assays. (A) Stem-loop RT-PCR verification of the expression patterns of nine conserved miRNAs in Nan Dan Ba Di Da Hua and Earlistaple 7 leaves after 4- and 24-h salt stress. The upper bar chart shows the relative expression of conserved miRNAs obtained by sequencing; the lower electropherogram indicates the relative expression levels of miRNA based on RT-PCR. (B) A combined view of inverse expression between a miRNA and its potential target in Earlistaple 7 under salt stress for 4 and 24 h according to qRT-PCR and stem-loop RT-PCR. miRNA expression (left side) was validated by sequencing of small RNAs isolated from control (ck) and salt-treated (4 and 24 h) samples. The miRNA targets (right side) were validated by transcriptome sequencing, and their expressions were checked by qRT-PCR. Up- or down-regulation in expression was normalized to U6 snRNA or Actin levels.