P-Glycoprotein4 Displays Auxin Efflux Transporter–Like Action in Arabidopsis Root Hair Cells and Tobacco Cells
Year: 2007
Type: article
Abstract: ATP binding cassette (ABC) transporters transport diverse substrates across membranes in various organisms. However, plant ABC transporters have only been scantily characterized. By taking advantage of the auxin-sensitive Arabidopsis thaliana root hair cell and tobacco (Nicotiana tabacum) suspension cell systems, we show here that Arabidopsis P-glycoprotein4 (PGP4) displays auxin efflux activity in plant cells. Root hair cell-specific overexpression of PGP4 (PGP4ox) and known auxin efflux transporters, such as PGP1, PGP19, and PIN-FORMEDs, decreased root hair elongation, whereas overexpression of the influx transporter AUXIN-RESISTANT1 enhanced root hair length. PGP4ox-mediated root hair shortening was rescued by the application of auxin or an auxin efflux inhibitor. These results indicate that the increased auxin efflux activity conferred by PGP4 reduces auxin levels in the root hair cell and consequently inhibits root hair elongation. PGP4ox in tobacco suspension cells also increased auxin efflux. PGP4 proteins were targeted to the plasma membrane of Arabidopsis root hair cells and tobacco cells without any clear subcellular polarity. Brefeldin A partially interfered with the trafficking of PGP4 reversibly, and this was rescued by pretreatment with auxin. These results suggest that PGP4 is an auxin efflux transporter in plants and that its trafficking to the plasma membrane involves both BFA-sensitive and -insensitive pathways.
Source: The Plant Cell
Authors: Misuk Cho, Sang Ho Lee, Hyung-Taeg Cho
Institutions: Chungnam National University, Gyeongsang National University
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $4,934
OpenAlex ID: W2142161645