To get better understanding of the association of H2S with
the auxin-induced lateral root development, we undertook a
primary study on the NAA- and NPA-induced H2S metabolism.
The time-course experiment (12 h; Fig. 2A) showed that DES
activity of tomato seedlings incubated in NAA for 1 h decreased
moderately, followed by a rapid and strong increase until 9 h,
and decline thereafter. Comparatively, under NPA treatment (in
particular) and control conditions, however, a weaker or moderate
activation of DES activity was respectively observed,
especially between 3 and 12 h of incubation. Meanwhile, a very
similar change was observed in endogenous H2S level during
the same treatment period upon NAA and NPA treatments
(Fig. 2B).