THE secret of how plants move may have been discovered. Kazuhisa Kameyama and
colleagues at Sophia University in Tokyo looked at the evergreen shrub
Mimosa pudica, which is famous for having leaves that droop when
touched.
The researchers found that after plants had moved, fewer phosphate groups
were bound to actin, a filamentous protein involved in cell shape and movement.
They think that this dephosphorylation alters the arrangement of actin, causing
the leaf stems to bend. Chemicals that block dephosphorylation reduce the degree
of bending, they found (Nature, vol 407, p 37).
