We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
An Aluminum-Activated Citrate Transporter in Barley.
- Authors
Jun Furukawa; Naoki Yamaji; Hua Wang; Namiki Mitani; Yoshiko Murata; Kazuhiro Sato; Maki Katsuhara; Kazuyoshi Takeda; Jian Feng Ma
- Abstract
Soluble ionic aluminum (Al) inhibits root growth and reduces crop production on acid soils. Al-resistant cultivars of barley (Hordeum vulgare L.) detoxify Al by secreting citrate from the roots, but the responsible gene has not been identified yet. Here, we identified a gene (HvAACT1) responsible for the Al-activated citrate secretion by fine mapping combined with microarray analysis, using an Al-resistant cultivar, Murasakimochi, and an Al-sensitive cultivar, Morex. This gene belongs to the multidrug and toxic compound extrusion (MATE) family and was constitutively expressed mainly in the roots of the Al-resistant barley cultivar. Heterologous expression of HvAACT1 in Xenopus oocytes showed efflux activity for 14C-labeled citrate, but not for malate. Two-electrode voltage clamp analysis also showed transport activity of citrate in the HvAACT1-expressing oocytes in the presence of Al. Overexpression of this gene in tobacco enhanced citrate secretion and Al resistance compared with the wild-type plants. Transiently expressed green fluorescent protein-tagged HvAACT1 was localized at the plasma membrane of the onion epidermal cells, and immunostaining showed that HvAACT1 was localized in the epidermal cells of the barley root tips. A good correlation was found between the expression of HvAACT1 and citrate secretion in 10 barley cultivars differing in Al resistance. Taken together, our results demonstrate that HvAACT1 is an Al-activated citrate transporter responsible for Al resistance in barley.
- Subjects
BARLEY; CHEMICAL inhibitors; CITRATES; CULTIVARS
- Publication
Plant & Cell Physiology, 2007, Vol 48, Issue 8, p1081
- ISSN
0032-0781
- Publication type
Article
- DOI
10.1093/pcp/pcm091