Abstract:
The effects of different concentrations of nitric oxide (NO) released by NO donors sodium nitroprusside (SNP) and S-nitrosoglutathione (GSNO) on stomatal movement of the abaxial epidermal strip of broad bean (Vicia faba L.) leaves were studied under light, darkness, in presence of H2O2 and ABA. The results showed that both SNP and GSNO at low and high concentration could induce not only the closure of opened-stomata under light but also the aperture of closed-stomata under darkness, H2O2 or ABA; Both SNP and GSNO at middle range of concentrations have no obvious effect on the aperture of opened-stomata under light, but induce the opening of closed-stomata under darkness, H2O2 or ABA. The recovery experiment results further showed that non-specific damage of cells was guarded in the high range of NO donors, but no guard in low and middle ranges of NO donors, because the high range-closed stomata was not reopened under a subsequent light recovery, but the low and middle range-closed or opened stomata could be reopened or reclosed by a subsequent light or dark recovery respectively. These results indicated that NO can induce not only stomatal closure, but also stomatal opening, which depend on the NO concentration in guard cells of Vicia faba.
