RT Journal Article
SR Electronic
T1 The Arabidopsis NRT1/PTR FAMILY Protein NPF7.3/NRT1.5 is an Indole-3-butyric Acid Transporter Involved in Root Gravitropism
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.06.04.131797
DO 10.1101/2020.06.04.131797
A1 Shunsuke Watanabe
A1 Naoki Takahashi
A1 Yuri Kanno
A1 Hiromi Suzuki
A1 Yuki Aoi
A1 Noriko Takeda-Kamiya
A1 Kiminori Toyooka
A1 Hiroyuki Kasahara
A1 Ken-Ichiro Hayashi
A1 Masaaki Umeda
A1 Mitsunori Seo
YR 2020
UL http://biorxiv.org/content/early/2020/06/05/2020.06.04.131797.abstract
AB Active membrane transport of plant hormones and their related compounds is an essential process that determines the distribution of the compounds within plant tissues and, hence, regulates various physiological events. Here, we report that the Arabidopsis NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY 7.3 (NPF7.3) protein functions as a transporter of indole-3-butyric acid (IBA), a precursor of the major endogenous auxin indole-3-acetic acid (IAA). When expressed in yeast, NPF7.3 mediated cellular IBA uptake. Loss-of-function npf7.3 mutants showed defective root gravitropism with reduced IBA levels and auxin responses. Nevertheless, the phenotype was restored by exogenous application of IAA but not by IBA treatment. NPF7.3 was expressed in pericycle cells and the root tip region including root cap cells of primary roots where the IBA-to-IAA conversion occurs. Our findings indicate that NPF7.3-mediated IBA uptake into specific cells is required for the generation of appropriate auxin gradients within root tissues.Competing Interest StatementThe authors have declared no competing interest.