Premium
Root avoidance of toxic metals requires the GeBP‐LIKE 4 transcription factor in Arabidopsis thaliana
Author(s) -
Khare Deepa,
Mitsuda Nobukata,
Lee Seungchul,
Song WonYong,
Hwang Daehee,
OhmeTakagi Masaru,
Martinoia Enrico,
Lee Youngsook,
Hwang JaeUng
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14242
Subject(s) - rhizosphere , arabidopsis thaliana , reactive oxygen species , cadmium , biology , lateral root , arabidopsis , transcription factor , shoot , botany , hyperaccumulator , phytoremediation , microbiology and biotechnology , chemistry , gene , biochemistry , bacteria , mutant , genetics , ecology , organic chemistry , contamination
Summary Plants reorganize their root architecture to avoid growth into unfavorable regions of the rhizosphere. In a screen based on chimeric repressor gene‐silencing technology, we identified the Arabidopsis thaliana GeBP‐LIKE 4 (GPL4) transcription factor as an inhibitor of root growth that is induced rapidly in root tips in response to cadmium (Cd). We tested the hypothesis that GPL 4 functions in the root avoidance of Cd by analyzing root proliferation in split medium, in which only half of the medium contained toxic concentrations of Cd. The wild‐type (WT) plants exhibited root avoidance by inhibiting root growth in the Cd side but increasing root biomass in the control side. By contrast, GPL 4‐suppression lines exhibited nearly comparable root growth in the Cd and control sides and accumulated more Cd in the shoots than did the WT. GPL 4 suppression also altered the root avoidance of toxic concentrations of other essential metals, modulated the expression of many genes related to oxidative stress, and consistently decreased reactive oxygen species concentrations. We suggest that GPL 4 inhibits the growth of roots exposed to toxic metals by modulating reactive oxygen species concentrations, thereby allowing roots to colonize noncontaminated regions of the rhizosphere.