Involvement of reactive oxygen species in lanthanum-induced inhibition of primary root growth.
Although lanthanum (La) has been used as an agricultural plant growth stimulant for approximately 50 years, high concentrations are toxic to plants. Despite significant advances in recent years, the mechanisms underlying the effects of La on root system development remain unclear. Here, we report that a high concentration of La inhibits primary root (PR) elongation and induces lateral root (LR) development. La results in cell death in PR tips, thereby leading to the loss of meristematic cell division potential, stem cell niche activity, and auxin distribution in PR tips. Further analysis indicated that La induces reactive oxygen species (ROS) over-accumulation in PR tips. Reduction in ROS accumulation partially alleviated the inhibitory effects of La on PR elongation by improving cell survival in PR tips and thereby improving meristematic cell division potential and auxin distribution in PR tips. We also found ROS to be involved in La-induced endocytosis. Genetic analyses supported the described phenotype. Overall, our results indicate that La affects root growth, at least partially, by modulating ROS levels in roots to induce cell death in PR tips and subsequent auxin redistribution in roots, leading to remodeling of the root system architecture.
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China.
Yang-Yang
YY
Liu
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China.
Ru-Ling
RL
Wang
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China.
Ping
P
Zhang
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China.
Liang-Liang
LL
Sun
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China xujin@xtbg.ac.cn.
Jin
J
Xu
D016923:Cell Death / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D007210:Indoleacetic Acids / Q000378:metabolism; D007811:Lanthanum / Q000494:pharmacology*; D018519:Meristem / Q000187:drug effects / Q000254:growth & development; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development; D017382:Reactive Oxygen Species / Q000378:metabolism*
D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D017382:Reactive Oxygen Species; D007811:Lanthanum
Arabidopsis; lanthanum; primary root growth; reactive oxygen species; root system architecture.