Thigmonastic response is mediated by touch-stimulated auxin signaling in cucumber tendrils
Ze Li1, Longlong Zheng1, Jiaqi Pan1
1Zhejiang Provincial Key Laboratory of Vegetable Germplasm Innovation and Quality Breeding, College of Horticulture, Zhejiang Agriculture and Forestry University, Hangzhou 311300, Zhejiang, China.
Abstract:
Thigmonasty is a fast and fascinating touch-stimulated response in plants. However, the molecular mechanism underlying this response is poorly understood. Here, the thigmonastic response (coiling) of tendrils in cucumber was investigated. The tendril exhibited a dorsal-ventral asymmetric structure and sensed touch stimuli via its ventral side. Touch stimuli initially induced contact coiling and then basipetally translocated to induce free coiling in tendrils. Indole-3-acetic acid and its biosynthesis genes exhibited in a touch-dependent pattern in tendrils. α-Naphthaleneacetic acid treatment induced tendril coiling without touch stimuli, whereas L-kynurenine + 4-phenoxyphenylboronic acid treatment inhibited touch-stimulated tendril coiling. In situ gene detection and TRSV-based gene silencing assay showed that CsaYUC7 (a YUCCA family member) was the key gene for touch-stimulated tendril coiling, and CsaYUC7 was directly regulated by the calmodulin-binding transcription activator CsaCAMTA4 in response to touch-induced Ca2+ signaling in tendrils. Our works showed touch-stimulated auxin biosynthesis and basipetally transportation in mediating tendril coiling, and it was regulated by a touch dependent Ca2+-CsaCAMTA4-CsaYUC7-auxin pathway, revealing the underlying signaling pathway and driving force of tendril coiling in cucumber.
Related Concept Videos
Responses to Gravity and Touch
Cell Signaling in Plants
Plant Hormones
Short-distance Transport of Resources
Tension Response at Adherens Junctions
α-Catenin as a Mechanosensory Protein
The α-catenin of adherens junctions is an allosteric protein with three VH (vinculin homology) domains...
Defenses Against Pathogens and Herbivores


