Auxins promote the growth of a tendril around a support by inducing differential cell elongation in response to touch, a process known as thigmotropism. When the tip of a tendril touches a support, the auxins (plant hormones) present in the tendril tip redistribute and accumulate on the side of the tendril that is away from the support. This asymmetric distribution causes the cells on the side away from the support to elongate faster than those on the contact side. As a result, the tendril bends and coils around the support, allowing the plant to attach and climb efficiently
. The mechanism involves:
- Touch perception: Mechanoreceptors in the tendril detect contact with the support.
- Auxin redistribution: Auxin transport proteins direct auxins to the non-contact side.
- Differential growth: Higher auxin concentration stimulates cell elongation on the non-contact side.
- Coiling: The tendril bends and twines around the support due to uneven growth rates on either side
Auxins facilitate this by loosening cell walls and promoting elongation, which is a fundamental role of auxins in plant growth and development
. In summary, auxins cause the tendril to coil around a support by accumulating on the side opposite the contact, promoting faster growth there, which results in the tendril bending and wrapping around the support structure
