Fig. 2

a Extracellular hemoglobin (Hb) as a quencher of endogenous NO from sunflower seedling roots. Seedling roots incubated in hemoglobin solution (2 mM and 3 mM) for 1 h followed by incubation in NO specific probe MnIP-Cu for 1 h. CLSM visualization of NO signal showed Hb concentration-dependent quenching of tissue NO. Roots were obtained from 2 day old dark-grown sunflower seedlings. Incubation medium without hemoglobin acts as control. b NO localization using CLSM in nuclei of root cells. Roots were obtained from 2 day old dark-grown sunflower seedlings. NO signal was visualized using MnIP-Cu. c Nuclei were visualized using DAPI. N Nuclei