Ca2+ Signal Transduction and Its Regulation Role under Drought Stress in Plant UV-B Activates Different Sources of H2O2 and Induces Stomatal Closure in Arabidopsis thaliana Leaves H2S Induced by H2O2 Mediates Drought-induced Stomatal Closure in Arabidopsis thaliana Extracellular Adenosine Triphosphate Functions Downstream of Hydrogen Sulfide in Ethylene-induced Stomatal Closure in Arabidopsis thaliana Hydrogen Sulfide Regulates Ethylene-induced Stomatal Closure in Arabidopsis thaliana Cytoplasmic Alkalization Mediates Exogenous Nitric Oxide-Induced Stomatal Closure in Vicia faba The Inhibitory Effects of Auxin and Cytokinin on Dark- and ABA-induced Stomatal Closure in Broad Bean Role of PI3P and Its Relationship with H2O2 or Nitric Oxide in Darkness-induced Stomatal Closure in Vicia faba STUDY ON THE STOMATAL ECOPHYSIOLOGICAL CHARACTERS OF TWO NEW CLONES OF Sect.Leuce