Abstract: The auxin transport and accumulation in plant can be indirectly indicated by the expression
level of PIN（PIN-FORMED）genes encoding auxin efflux carriers. To identify the role of auxin in the
initial development of Rosa canina protocorm-like body（PLB），two PIN genes RcPIN1（GenBank No.
KF543362）and RcPIN2（GenBank No. KF543363）were isolated from adventitious roots of R. canina
callus. The full cDNA of RcPIN1 was 2 266 bp in length and encoded a protein of 621 amino acids，that of
RcPIN1 was 2 248 bp and encoded 643 amino acids，and they demonstrate a relatively high similarity in
the two groups of membrane-spanning domains，located at the N- and C-termini of the proteins，and high heterogeneity in the central hydrophilic region. Blast exhibited that RcPIN1 and RcPIN2 were highly
homologous to other PINs（> 70%）. Semi-quantitative RT-PCR analysis showed that the expression level
of RcPIN1 was higher in the root and stem than the leaf and flower，while that of RcPIN2，the root than the
stem，leaf and flower. During the initial occurrence of R. canina PLB，high expression of RcPIN1 and
RcPIN2 was induced in the callus-roots by TDZ culture，while in the presence of TIBA the two genes were
inactive and less PLB formed finally. Our data suggested that auxin plays a important roles during the
initial morphogenesis of R. canina PLB.

Key words: Rosa canina, PIN, auxin, auxin efflux carrier, protocorm-like body