A combined view of correlated expression between a miRNA and its target in cotton under early- and late-stage salt stress. Pearson correlation coefficients (PCCs) between the expression of miRNAs and miRNA targets were calculated. Black circles represent miRNA and target pairs. PCCs are represented by the linear slope and are listed numerically, with A, B and C indicating all, negative, and positive correlations for 4-h, respectively. The same means with D, E and F for 24-h.