Abstract
When supplied with arsenate (As(V)), plant roots extrude a substantial amount of arsenite (As(III)) to the external medium through as yet unidentified pathways. The rice (Oryza sativa) silicon transporter Lsi1 (OsNIP2;1, an aquaporin channel) is the major entry route of arsenite into rice roots. Whether Lsi1 also mediates arsenite efflux was investigated. Expression of Lsi1 in Xenopus laevis oocytes enhanced arsenite efflux, indicating that Lsi1 facilitates arsenite transport bidirectionally. Arsenite was the predominant arsenic species in arsenate-exposed rice plants. During 24-h exposure to 5 lM arsenate, rice roots extruded arsenite to the external medium rapidly, accounting for 60-90% of the arsenate uptake. A rice mutant defective in Lsi1 (lsi1) extruded significantly less arsenite than the wild-type rice and, as a result, accumulated more arsenite in the roots. By contrast, Lsi2 mutation had little effect on arsenite efflux to the external medium. We conclude that Lsi1 plays a role in arsenite efflux in rice roots exposed to arsenate. However, this pathway accounts for only 15-20% of the total efflux, suggesting the existence of other efflux transporters.
| Original language | English |
|---|---|
| Pages (from-to) | 392-399 |
| Number of pages | 8 |
| Journal | New Phytologist |
| Volume | 186 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Apr 2010 |
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Keywords
- Aquaporin
- Arsenic accumulation
- Arsenite (As(III)) efflux
- Rice
- Silicon transporter
ASJC Scopus subject areas
- Plant Science
- Physiology
- Medicine(all)
Cite this
The role of the rice aquaporin Lsi1 in arsenite efflux from roots. / Zhao, Fang Jie; Ago, Yukiko; Mitani, Namiki; Li, Ren Ying; Su, Yu Hong; Yamaji, Naoki; McGrath, Steve P.; Ma, Jian Feng.
In: New Phytologist, Vol. 186, No. 2, 04.2010, p. 392-399.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The role of the rice aquaporin Lsi1 in arsenite efflux from roots
AU - Zhao, Fang Jie
AU - Ago, Yukiko
AU - Mitani, Namiki
AU - Li, Ren Ying
AU - Su, Yu Hong
AU - Yamaji, Naoki
AU - McGrath, Steve P.
AU - Ma, Jian Feng
PY - 2010/4
Y1 - 2010/4
N2 - When supplied with arsenate (As(V)), plant roots extrude a substantial amount of arsenite (As(III)) to the external medium through as yet unidentified pathways. The rice (Oryza sativa) silicon transporter Lsi1 (OsNIP2;1, an aquaporin channel) is the major entry route of arsenite into rice roots. Whether Lsi1 also mediates arsenite efflux was investigated. Expression of Lsi1 in Xenopus laevis oocytes enhanced arsenite efflux, indicating that Lsi1 facilitates arsenite transport bidirectionally. Arsenite was the predominant arsenic species in arsenate-exposed rice plants. During 24-h exposure to 5 lM arsenate, rice roots extruded arsenite to the external medium rapidly, accounting for 60-90% of the arsenate uptake. A rice mutant defective in Lsi1 (lsi1) extruded significantly less arsenite than the wild-type rice and, as a result, accumulated more arsenite in the roots. By contrast, Lsi2 mutation had little effect on arsenite efflux to the external medium. We conclude that Lsi1 plays a role in arsenite efflux in rice roots exposed to arsenate. However, this pathway accounts for only 15-20% of the total efflux, suggesting the existence of other efflux transporters.
AB - When supplied with arsenate (As(V)), plant roots extrude a substantial amount of arsenite (As(III)) to the external medium through as yet unidentified pathways. The rice (Oryza sativa) silicon transporter Lsi1 (OsNIP2;1, an aquaporin channel) is the major entry route of arsenite into rice roots. Whether Lsi1 also mediates arsenite efflux was investigated. Expression of Lsi1 in Xenopus laevis oocytes enhanced arsenite efflux, indicating that Lsi1 facilitates arsenite transport bidirectionally. Arsenite was the predominant arsenic species in arsenate-exposed rice plants. During 24-h exposure to 5 lM arsenate, rice roots extruded arsenite to the external medium rapidly, accounting for 60-90% of the arsenate uptake. A rice mutant defective in Lsi1 (lsi1) extruded significantly less arsenite than the wild-type rice and, as a result, accumulated more arsenite in the roots. By contrast, Lsi2 mutation had little effect on arsenite efflux to the external medium. We conclude that Lsi1 plays a role in arsenite efflux in rice roots exposed to arsenate. However, this pathway accounts for only 15-20% of the total efflux, suggesting the existence of other efflux transporters.
KW - Aquaporin
KW - Arsenic accumulation
KW - Arsenite (As(III)) efflux
KW - Rice
KW - Silicon transporter
UR - http://www.scopus.com/inward/record.url?scp=77954709208&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77954709208&partnerID=8YFLogxK
U2 - 10.1111/j.1469-8137.2010.03192.x
DO - 10.1111/j.1469-8137.2010.03192.x
M3 - Article
C2 - 20163552
AN - SCOPUS:77954709208
VL - 186
SP - 392
EP - 399
JO - New Phytologist
JF - New Phytologist
SN - 0028-646X
IS - 2
ER -