story to find out more.
Tendrils of redvine
can latch onto crop plants and coil around them for support. The tendrils even
make their own glue. Click the image for more information about
New Insight into How Burdensome Weed Climbs
Surfaces By Jim
Core September 15, 2005
The way in which a problematic weed overruns and secures itself to
crops and man-made structures--and how it clings to the surfaces it climbs--has
been revealed by Agricultural Research
Redvine (Brunnichia ovata), a perennial woody vine that
regenerates new growth from woody rootstocks and climbs by its tendrils, is a
big problem for Mississippi Delta crops, especially soybeans.
Tendrils are organs used by some vines to assist their climbing, but
little has been known about how they develop or support the vine. At the ARS
Weed Science Research Unit in Stoneville, Miss., plant physiologist
C. Vaughn and post-doctoral scientist
G. Meloche discovered two unique aspects of redvine tendrils.
Redvine tendrils begin as straight, thin and flexible appendages of
the shoot. Vaughn and Meloche discovered that epidermal cells along the length
of the vine's tendril expand in response to touch by elongating toward a
stimulus. The tendrils themselves, as a whole, respond by coiling around the
object for support. Cells enriched with phenols break apart as the tendrils rub
against the object. Then the phenols react with an enzyme, polyphenol oxidase
(PPO), to produce a sticky, phenolic polymer cement used by the tendrils to
stick to the vine's climbing surface.
This is the first time the PPO enzyme has been implicated in
generating an adhesive in a climbing plant. In another first, the researchers
also discovered that the weed's tendrils produce gelatinous fiber cells, the
same structures found in leaning trees trying to right themselves. These fiber
cells are also enriched in lignin to radically increase their strength. Then
the cells automatically die, which leads to a dry, rigid coil structure
securely anchoring the vine to the support.
The researchers found a unique cell wall composition with this process
and are looking at steps in the metabolic pathways that might be inhibited to
about this research in the September 2005 issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief in-house scientific research agency.