Pharmacological study of two potential Ca superior 2 superior + signalling pathways within stomatal closing in response to abscisic acid in Commelina communis L.

摘要

It has been previously suggested that, depending on its applied concentration, abscisic acid (ABA) induces stomatal closing through one of two potential Ca superior 2 superior +-dependent transduction pathways. This hypothesis was worked further in Commelina communis by comparing the stomatal responses to 10 nM ABA (ABA inferior 1 inferior 0) and 100 nM ABA (ABA inferior 1 inferior 0 inferior 0) on the basis of a pharmacological dissection of implicated Ca superior 2 superior + signalling. Compared to the ABA inferior 1 inferior 0 response, the response to ABA inferior 1 inferior 0 inferior 0 was differentially affected by the putative plant modulators of Ca superior 2 superior + fluxes caffeine, ruthenium red, procaine, SDZ-202 791 S(+), S-(-)-BAY K8644 and SDZ-202 791 R(-). Furthermore, the ABA inferior 1 inferior 0 inferior 0 response specifically displayed positive interactions between the plant Ca superior 2 superior + buffer 1,2-bis(o-aminophenoxy)ethane- N,N,N',N'-tetraacetic acid (BAPTA) and the anion channel blockers anthracene- 9-carboxylic acid, [(6,7-dichloro-2-cyclopentenyl-2,3-dihydro-2-methyl-1- oxo-1H-inden-5-yl)oxy]acetic acid or 2-( alpha , alpha , alpha -trifluoro-m-toluidine)- pyridine-3-carboxylic acid, whereas the anion channel blocker 5-nitro-2,3- phenylpropyllamine benzoic acid positively interacted with BAPTA to prevent both the ABA inferior 1 inferior 0 and ABA inferior 1 inferior 0 inferior 0 responses. Together, these results might support indirectly that stomatal closing in a graded response to increasing concentrations of exogenous ABA proceeds from different Ca superior 2 superior + signalling pathways.