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Updated: Jun 20, 2026

A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response
Published on: April 17, 2016
Auxin, gibberellins and the gravitropic response of grass leaf sheath pulvini
1School of Plant Science; University of Tasmania; Hobart; Tasmania, Australia.
Abstract:
The role of hormones in mediating tropic responses has been a central question in plant biology. Another key issue concerns how interactions between hormones regulate plant responses. In the September 2007 issue of Physiologia Plantarum, we published a paper relevant to both these questions.1 This paper focuses on gravitropism in the barley leaf sheath pulvinus. The results support the Cholodny-Went theory on hormones and tropic responses, and highlight how an environmental factor (gravity) appears to first affect auxin content and consequently that of bioactive gibberellins (GAs). It appears that while GAs do not actually trigger the gravitropic bending of barley pulvini, they do act to magnify the bending response.
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