Root gravitropism requires lateral root cap and epidermal cells for transport and response to a mobile auxin signal. Swarup, R., Kramer, E. M., Perry, P., Knox, K., Leyser, H. M. O., Haseloff, J., Beemster, G. T. S., Bhalerao, R. P., & Bennett, M. J. Nature Cell Biology, 7(11):1057–1065, November, 2005. Number: 11 Publisher: Nature Publishing Group
Root gravitropism requires lateral root cap and epidermal cells for transport and response to a mobile auxin signal [link]Paper  doi  abstract   bibtex   
Re-orientation of Arabidopsis seedlings induces a rapid, asymmetric release of the growth regulator auxin from gravity-sensing columella cells at the root apex. The resulting lateral auxin gradient is hypothesized to drive differential cell expansion in elongation-zone tissues. We mapped those root tissues that function to transport or respond to auxin during a gravitropic response. Targeted expression of the auxin influx facilitator AUX1 demonstrated that root gravitropism requires auxin to be transported via the lateral root cap to all elongating epidermal cells. A three-dimensional model of the root elongation zone predicted that AUX1 causes the majority of auxin to accumulate in the epidermis. Selectively disrupting the auxin responsiveness of expanding epidermal cells by expressing a mutant form of the AUX/IAA17 protein, axr3-1, abolished root gravitropism. We conclude that gravitropic curvature in Arabidopsis roots is primarily driven by the differential expansion of epidermal cells in response to an influx-carrier-dependent auxin gradient.
@article{swarup_root_2005,
	title = {Root gravitropism requires lateral root cap and epidermal cells for transport and response to a mobile auxin signal},
	volume = {7},
	copyright = {2005 Nature Publishing Group},
	issn = {1476-4679},
	url = {https://www.nature.com/articles/ncb1316},
	doi = {10.1038/ncb1316},
	abstract = {Re-orientation of Arabidopsis seedlings induces a rapid, asymmetric release of the growth regulator auxin from gravity-sensing columella cells at the root apex. The resulting lateral auxin gradient is hypothesized to drive differential cell expansion in elongation-zone tissues. We mapped those root tissues that function to transport or respond to auxin during a gravitropic response. Targeted expression of the auxin influx facilitator AUX1 demonstrated that root gravitropism requires auxin to be transported via the lateral root cap to all elongating epidermal cells. A three-dimensional model of the root elongation zone predicted that AUX1 causes the majority of auxin to accumulate in the epidermis. Selectively disrupting the auxin responsiveness of expanding epidermal cells by expressing a mutant form of the AUX/IAA17 protein, axr3-1, abolished root gravitropism. We conclude that gravitropic curvature in Arabidopsis roots is primarily driven by the differential expansion of epidermal cells in response to an influx-carrier-dependent auxin gradient.},
	language = {en},
	number = {11},
	urldate = {2021-06-11},
	journal = {Nature Cell Biology},
	author = {Swarup, Ranjan and Kramer, Eric M. and Perry, Paula and Knox, Kirsten and Leyser, H. M. Ottoline and Haseloff, Jim and Beemster, Gerrit T. S. and Bhalerao, Rishikesh P. and Bennett, Malcolm J.},
	month = nov,
	year = {2005},
	note = {Number: 11
Publisher: Nature Publishing Group},
	pages = {1057--1065},
}

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