Hydrogen sulfide modulates actin-dependent auxin transport via regulating ABPs results in changing of root development in Arabidopsis

Hydrogen sulfide (H(2)S) signaling has been considered a key regulator of plant developmental processes and defenses. In this study, we demonstrate that high levels of H(2)S inhibit auxin transport and lead to alterations in root system development. H(2)S inhibits auxin transport by altering the polar subcellular distribution of PIN proteins. The vesicle trafficking and distribution of the PIN proteins are an actin-dependent process. H(2)S changes the expression of several actin-binding proteins (ABPs) and decreases the occupancy percentage of F-actin bundles in the Arabidopsis roots. We observed the effects of H(2)S on F-actin in T-DNA insertion mutants of cpa, cpb and prf3, indicating that the effects of H(2)S on F-actin are partially removed in the mutant plants. Thus, these data imply that the ABPs act as downstream effectors of the H(2)S signal and thereby regulate the assembly and depolymerization of F-actin in root cells. Taken together, our data suggest that the existence of a tightly regulated intertwined signaling network between auxin, H(2)S and actin that controls root system development. In the proposed process, H(2)S plays an important role in modulating auxin transport by an actin-dependent method, which results in alterations in root development in Arabidopsis.