Root-to-shoot long-distance circulation of nicotianamine and nicotianamine-nickel chelates in the metal hyperaccumulator Thlaspi caerulescens
Plant metal hyperaccumulator species are widely used as models to unravel the heavy metal tolerance and hyperaccumulation mechanisms. Thlaspi caerulescens is capable of tolerating and hyperaccumulating Zn, Cd, and Ni. A search for factors involved in the cellular tolerance to Ni, based on yeast scre...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 57(2006), 15 vom: 15., Seite 4111-22 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2006
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Chelating Agents Plant Proteins RNA, Messenger nicotianamine 34441-14-0 Azetidinecarboxylic Acid 5GZ3E0L9ZU Nickel mehr... |
| Zusammenfassung: | Plant metal hyperaccumulator species are widely used as models to unravel the heavy metal tolerance and hyperaccumulation mechanisms. Thlaspi caerulescens is capable of tolerating and hyperaccumulating Zn, Cd, and Ni. A search for factors involved in the cellular tolerance to Ni, based on yeast screens, led to isolation of a cDNA encoding a functional nicotianamine (NA) synthase (NAS). The T. caerulescens genome appears to contain a single copy of the NAS gene named TcNAS whose expression is restricted to the leaves. The analysis of dose-response and time-course Ni treatments have revealed that the exposure to Ni triggers the accumulation of NA in the roots. Because neither TcNAS expression nor NAS activity were detected in the roots, the NA accumulation in roots is most probably the result of its translocation from the leaves. Once in the roots, NA, together with Ni, is subsequently found in the xylem, for redirection to the aerial parts. Using liquid chromatography coupled to inductively coupled plasma or electrospray ionization mass spectrometry, it has been shown that part of the Ni is translocated as a stable Ni-NA complex in the xylem sap. This circulation of NA, Ni, and NA-Ni chelates is absent in the non-tolerant non-hyperaccumulator related species T. arvense. Taken together, the results provide direct physiological and chemical evidence for NA and NA-heavy metal complex translocation in a hyperaccumulator species |
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| Beschreibung: | Date Completed 05.03.2007 Date Revised 01.12.2018 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |