Restricted spatial expression of a high-affinity phosphate transporter in potato roots
Restricted spatial expression of a high-affinity phosphate transporter in potato roots
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DOI：
10.1242/jcs.00615
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发表时间：
2003-08-01
影响因子：
4
通讯作者：
Leggewie, G
中科院分区：
文献类型：
--
作者：
Gordon-Weeks, R;Tong, YP;Leggewie, G
磷缺乏限制植物生长，而Pht 1家族的高亲和力磷酸盐转运蛋白促进磷酸盐吸收和转运。该家族可细分为根特异性、磷酸盐剥夺诱导的成员和也在叶子中表达的成员。StPT 2，马铃薯根特异性转运蛋白的抗体，检测到两个条带（52 kDa和30 kDa）的蛋白质印迹的根质膜提取物是最强烈的，在整个提取物从根尖和轻微增加整个根在响应磷酸盐耗竭。使用StPT 2特异性引物的RT-PCR证实了这些发现。低倍共聚焦免疫荧光图像显示StPT 2主要在根尖的伸长区表达。相比之下，液泡焦磷酸酶和质膜ATP酶抗体标记的整个根。高倍图像显示，通过与α-微管蛋白、细胞壁和质膜ATP酶标记的比较，StPT 2位于表皮质膜中并局限于顶端表面。这是植物营养转运蛋白极性质膜定位的第一个证据，与StPT 2在磷酸盐捕获和吸收中的作用一致。
Phosphorus deficiency limits plant growth, and high-affinity phosphate transporters, of the Pht1 family, facilitate phosphate uptake and translocation. The family is subdivided into root specific, phosphate deprivation induced members and those also expressed in leaves. An antibody to StPT2, a potato root specific transporter, detected two bands (52 kDa and 30 kDa) on western blots of root plasma membrane extracts that were most intense in whole extracts from the root tip and slightly increased throughout the root in response to phosphate depletion. RT-PCR, using StPT2 specific primers, confirmed these findings. Low power confocal immunofluorescent images showed StPT2 expression mainly in the elongation zone at the root tip. By contrast, a vacuolar pyrophosphatase and a plasma membrane ATPase antibody labelled the whole root. High power images showed, by comparison with alpha-tubulin, cell wall and plasma membrane ATPase labelling, that StPT2 was in the epidermal plasma membrane and restricted to the apical surface. This is the first evidence of polar plasma membrane localisation of a plant nutrient transporter and is consistent with a role for StPT2 in phosphate capture and uptake.