Adventitious roots occur naturally in many species, and can also be induced
from explants of some tree species including poplar, providing an important
means of clonal propagation. Auxin has been identified as playing a crucial
role in adventitious root formation, but the associated mechanism needs to
be explored.

Led by Wenbo Shu, a Chinese Academy of Forestry research team studied the
role of PagFBL1, a homolog of the Arabidopsis auxin receptor TIR1 in hybrid
poplar (Populus alba × P. glandulosa clone 84K), in its adventitious root
formation.



PagFBL1 expression was found to be concentrated in the cambium and secondary
phloem in stems during adventitious root induction and initiation phases.
Overexpressing PagFBL1 stimulated adventitious root formation and increased
root biomass. Meanwhile, knockdown of PagFBL1 resulted in delayed
adventitious root formation and decreased root biomass.

This study suggests that PagFBL1 promotes adventitious rooting and could be
targeted to improve Populus propagation by cuttings.



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