Heavy metal homeostasis in plants and application

第111回 Plant Science Seminar
Heavy metal homeostasis in
plants and application
Dr. Kuo-Chen Yeh
Agricultural Biotechnology Research Center,
Academia Sinica,Taipei, Taiwan
日時 : 9月8日 (月) 13:00〜14:00
場所 : 農学部総合研究棟一階多目的室(W109)
Plants acquire nutrients, including heavy metals, form soil. The in-depth
understanding of the action mechanisms of heavy metal homoeostasis is essential for
future materialization of phytoremediation and biofortification. A balanced heavy metal
homeostasis relies on seamless integration of uptake, transport and
sequestration/detoxification. However, this line of research is still in its juvenile stage.
In addition, physiological impacts under various metal conditions are largely unknown.
To fill the gap in knowledge of heavy metal homeostasis, my lab started the study of
hyperaccumulators. In addition to revealing genes related to classical heavy metal
homeostasis, we have learned of the critical strategies Arabidopsis halleri, a heavy
metal accumulator, uses for Zn tolerance and accumulation. We found that the
maintenance of Fe homeostasis is most important for plants to survive in the heavy
metal–rich habitat. The mechanisms include adjusted gene expression for Fe
acquisition and “protectant” secretion to protect against toxicity in an excess Zn
environment. Researches derived from this hypothesis will be discussed in the
seminar. Nevertheless, we made additional efforts to study Fe homeostasis and
functions to understand the importance of the metal in the defense against heavy
metal stress. We hope that our discoveries made in the past few years could expand
the knowledge in key steps of heavy metal homeostasis, including the processes of
acquisition, detoxification and the physiological impacts of metals.
1. M. Tsednee, S.-C. Yang, D.-C. Lee and K.-C. Yeh* (2014) Root-secreted nicotianamine from
Arabidopsis halleri facilitates zinc hypertolerance by regulating zinc bioavailability. Plant Physiology in
press: 2. L.-J. Shin, J.-C. Lo, G.-H. Chen, J. Callis, H. Fu and K.-C. Yeh* (2013) IRT1 DEGRADATION
FACTOR 1, a RING E3 ubiquitin ligase, regulates the degradation of IRON-REGULATED TRANSPORTER
1 in Arabidopsis. Plant Cell 25: 3039-3051; 3. Y.-Y. Chen, Y Wang, L.-J. Shin, J.-F. Wu, V. Shanmugam,
M. Tsednee, J.-C. Lo, C.-C. Chen, S.-H. Wu and K.-C. Yeh* (2013) Iron is involved in the maintenance of
circadian period length in Arabidopsis. Plant Physiology 161: 1409-1420; 4. V. Shanmugam, M. Tsednee
and K.-C. Yeh* (2012) ZINC TOLERANCE INDUCED BY IRON 1 reveals the importance of glutathione in
the cross homeostasis between zinc and iron in Arabidopsis thaliana. Plant Journal 69 (6): 1006-1017
Plant Science Seminar 北大内で植物科学を研究している(特に)若い人たちの交流促進
世話人: 高野順平(内線:3888)