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Updated: Aug 8, 2026

A Simple Protocol for Mapping the Plant Root System Architecture Traits
Published on: February 10, 2023
Distribution of G-actin is related to root hair growth of wheat
1State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China.
Background And Aims:
Actin distribution in root hair tips is a controversial topic. Although the relationship between Ca2+ gradient and actin dynamics in plant tip-growth has been a focus of study, there is still little direct evidence on the exact relationship in root hair tip-growth.
Methods:
G-actin was labelled by fluorescein isothiocyanate-DNase I. F-actin was labelled by tetramethylrhodamine isothiocyanate-phalloidin. Actin in root hairs of Triticum aestivum (wheat) was investigated using confocal laser-scanning microscopy.
Key Results:
Thick F-actin bundles did not extend into a region of approx. 5-10 microm from the tip of the growing root hairs, although they gave off branches of fine actin filaments in the hair tips. A tip-focused G-actin gradient was shown at the extreme apex of growing root hairs. In full-grown wheat root hairs, the tip-focused G-actin gradient disappeared while the thick F-actin bundles extended into the tips. BAPTA-AM, a Ca2+ disruption agent, also caused the tip-focused G-actin gradient to disappear and the diffuse F-actin bundles to appear in the tips of wheat root hairs.
Conclusions:
These results suggest that the tip-focused gradient of intracellular G-actin concentration at the extreme apex may be essential for root hair growth, and that preserving the tip-focused gradient needs a high Ca2+ concentration in the root hair tips.
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