Manganese Toxicity Inhibited Root Growth by Disrupting Auxin Biosynthesis and Transport inArabidopsis.
Mn toxicity inhibits both primary root (PR) growth and lateral root development. However, the mechanism underlying Mn-mediated root growth inhibition remains to be further elucidated. Here, we investigated the role of auxin in Mn-mediated inhibition of PR growth inArabidopsisusing physiological and genetic approaches. Mn toxicity inhibits PR elongation by reducing meristematic cell division potential. Mn toxicity also reduced auxin levels in root tips by reducing IAA biosynthesis and down-regulating the expression of auxin efflux carriersPIN4andPIN7. Loss of functionpin4andpin7mutants showed less inhibition of root growth thancol-0seedlings. These results indicated that this inhibitory effect of Mn toxicity on PR growth was mediated by affecting auxin biosynthesis and the expression of auxin efflux transporters PIN4 and PIN7.
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming China.
Jingjing
J
Zhao
College of Life Science and Geography, Qinghai Normal University Xining, China.
Wenying
W
Wang
Northwest Institute of Plateau Biology, Chinese Academy of Sciences Xining, China.
Huakun
H
Zhou
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming China.
Ruling
R
Wang
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming China.
Ping
P
Zhang
College of Life Science and Geography, Qinghai Normal University Xining, China.
Huichun
H
Wang
College of Environment, Zhejiang University of Technology Hangzhou, China.
Xiangliang
X
Pan
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming China.
Jin
J
Xu
Arabidopsis; auxin accumulation; auxin efflux carriers; manganese (Mn) toxicity; primary root growth