  Environment plays a critical role in the star formation history of galaxies.
Tidal and hydrodynamical stripping, prominent in cluster environment, can
remove the peripheral gas of galaxies and star formation may thus be
environmentally suppressed from the outside-in. We revisit the environmental
dependence of the radial gradient of specific star formation rate (sSFR)
profile. We probe the radial gradient by using the archival spectral indices
D4000n and HdA measured from SDSS fiber spectra, to indicate central sSFR, and
the total sSFR from fitting the spectral energy distribution. Despite the low
spatial resolution, the wealth of SDSS data allows to disentangle the
dependences on stellar mass, sSFR, and environment. We find that low-mass
satellite galaxies in the mass range 9 < log M/M_solar < 9.8 on average quench
in more inside-out pattern compared to isolated galaxies matched in mass, sSFR,
and fiber coverage. This environmental effect is particularly strong for
galaxies below the star formation main sequence, and peaks for those in the
core of massive clusters where the phase-space diagram reveals clear links
between the inside-out quenching and orbital properties. Our results suggest
that both tidal and hydrodynamical interactions in cluster environment suppress
the star formation of satellites mainly from the inside-out. As accreted gas of
low angular momentum from hot gas halos is an important source for replenishing
central gas reservoir, we discuss how gas stripping in clusters may lead to
starvation and cause inside-out quenching when the outer star-forming discs are
not significantly affected.
