title: OPT3 Is a Phloem-Specific Iron Transporter That Is Essential for Systemic Iron Signaling and Redistribution of Iron and Cadmium in Arabidopsis.
abstract: Iron is essential for both plant growth and human health and nutrition. Knowledge of the signaling mechanisms that communicate iron demand from shoots to roots to regulate iron uptake as well as the transport systems mediating iron partitioning into edible plant tissues is critical for the development of crop biofortification strategies. Here, we report that OPT3, previously classified as an oligopeptide transporter, is a plasma membrane transporter capable of transporting transition ions in vitro. Studies in Arabidopsis thaliana show that OPT3 loads iron into the phloem, facilitates iron recirculation from the xylem to the phloem, and regulates both shoot-to-root iron signaling and iron redistribution from mature to developing tissues. We also uncovered an aspect of crosstalk between iron homeostasis and cadmium partitioning that is mediated by OPT3. Together, these discoveries provide promising avenues for targeted strategies directed at increasing iron while decreasing cadmium density in the edible portions of crops and improving agricultural productivity in iron deficient soils.
authors.affiliation: Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853.
authors.forename: Zhiyang
authors.initials: Z
authors.lastname: Zhai
authors.affiliation: Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853.
authors.forename: Sheena R
authors.initials: SR
authors.lastname: Gayomba
authors.affiliation: Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853.
authors.forename: Ha-Il
authors.initials: HI
authors.lastname: Jung
authors.affiliation: Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853.
authors.forename: Nanditha K
authors.initials: NK
authors.lastname: Vimalakumari
authors.affiliation: Robert W. Holley Center for Agriculture and Health, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853.
authors.forename: Miguel
authors.initials: M
authors.lastname: Piñeros
authors.affiliation: Robert W. Holley Center for Agriculture and Health, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853.
authors.forename: Eric
authors.initials: E
authors.lastname: Craft
authors.affiliation: Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853 Robert W. Holley Center for Agriculture and Health, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Rutzke
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, AS24 3UU Scotland, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Danku
authors.affiliation: Center for Plant Environmental Stress Physiology, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Brett
authors.initials: B
authors.lastname: Lahner
authors.affiliation: Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755.
authors.forename: Tracy
authors.initials: T
authors.lastname: Punshon
authors.affiliation: Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755.
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Guerinot
authors.affiliation: Institute of Biological and Environmental Sciences, University of Aberdeen, AS24 3UU Scotland, United Kingdom.
authors.forename: David E
authors.initials: DE
authors.lastname: Salt
authors.affiliation: Robert W. Holley Center for Agriculture and Health, U.S. Department of Agriculture-Agricultural Research Service, Ithaca, New York 14853.
authors.forename: Leon V
authors.initials: LV
authors.lastname: Kochian
authors.affiliation: Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853 okv2@cornell.edu.
authors.forename: Olena K
authors.initials: OK
authors.lastname: Vatamaniuk