Sodium nitroprusside stimulates growth and shoot regeneration in chrysanthemum

Abstract

In this study, we demonstrate that the nitric oxide (NO) donor sodium nitroprusside (SNP) improves plant regeneration in chrysanthemums. Internode explants of three different chrysanthemum cultivars, ‘White ND’, ‘White wing × Peach ND’, and ‘Hunt × Lemon ND’, were cultured on shoot induction medium (SIM) containing various concentrations of N6–benzyladenine (2.22 or 4.44 μM BA) and SNP (0.83–6.71 μM) individually and in combination. Most combinations of BA and SNP significantly improved the morphogenetic potential of internode explants and enhanced shoot regeneration in all three chrysanthemum cultivars compared to treatment with BA alone. The cultivar ‘White wing × Peach ND’ displayed the highest regeneration response (98.3%) and shoot regeneration rate (27.3 shoots/explant) in SIM containing optimal BA (4.44 μM) and SNP (0.83 μM) concentrations within 30 days of culture. Individual shoots of ‘White wing × Peach ND’ were transferred to root induction medium (RIM) containing various concentrations of SNP (0.83–6.71 μM) alone. Shoots rooted in the presence of SNP resulted in healthy plantlets within 30 days of culture with improved root (number of roots/shoot, root length, and fresh weight) and shoot (number of leaves, shoot length, and fresh weight) growth characteristics compared to the control. In addition, the regeneration procedure described in this study only requires a short duration (60 days) to obtain rooted plantlets from internode explants of chrysanthemums. Our results suggest that supplementation of chrysanthemum regeneration medium with SNP enhances shoot regeneration and improves plant growth, overcoming problems associated with propagation and genetic transformation.