Characterization of MADS-boxgene family and its unique response to drought and nickel stresses with melatonin-mediated tolerance in dragon fruit (Selenicereus undatusL.)

•Abiotic stress factors (drought and nickel) severely affect the growth and productivity of pitaya.•Melatonin enhanced gene expression level of HuMADS-boxgenes and tolerance in pitaya against drought and nickel stresses.•HuMADS-15interacted significantly with other genes and showed high expression in single and combined stresses throughout the tissues as compared to the control.