Sphingosine-1-phosphate mediates stomatal closure caused by darkness via inducing nitric oxide synthesis in guard cells of Vicia faba L.

摘要

The relationship between sphingosine-1-phosphate (S1P) and the change of nitric oxide (NO) levels in guard cells of Vicia faba L. during darkness-induced stomatal closure was investigated. Results show that darkness closed stomata while increasing nitric oxide (NO) levels in guard cells. DL-threo- dihydrosphingosine (DL-threo-DHS) and N,N-dimethylsphingosine (DMS), two inhibitors of long-chain base kinases, not only suppressed darkness-induced stomatal closure but also inhibited NO synthesis caused by darkness, as did cPTIO (a specific NO scavenger) and L-NAME (an inhibitor of NO synthase). Additionally, exogenous S1P triggered stomatal closure and NO synthesis, but S1P-induced stomatal closure and NO synthesis were distinctly suppressed by cPTIO and L-NAME. Altogether, present data suggested that S1P mediated stomatal closure caused by darkness via inducing nitric oxide synthesis in guard cells of Vicia faba.