Sucrose transport in the phloem: integrating root responses to phosphorus starvation
Sucrose transport in the phloem: integrating root responses to phosphorus starvation
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DOI：
10.1093/jxb/erm221
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发表时间：
2008-01-01
影响因子：
6.9
通讯作者：
White, Philip J.
中科院分区：
文献类型：
--
作者：
Hammond, John P.;White, Philip J.
植物中的糖来源于光合作用，作为能量代谢和复杂碳水化合物生物合成的底物，为库组织提供生长和发育所需的资源。此外，糖可以充当第二信使，具有调节植物生长和发育以响应生物和非生物胁迫的能力。糖信号网络具有直接调节基因表达和与其他信号通路相互作用的能力。光合产物主要以蔗糖的形式通过韧皮部运输到库组织。在磷（P）饥饿的情况下，植物会在叶子中积累糖和淀粉。在磷饥饿条件下，韧皮部蔗糖负荷的增加不仅起到将碳资源重新定位到根的作用，这增加了它们相对于地上部的大小，而且还具有启动糖信号级联的潜力，所述糖信号级联改变参与优化根生物化学的基因的表达，以通过增加无机磷转运蛋白的表达和活性来获得土壤磷，分泌酸性磷酸酶和有机酸释放土壤中的磷，以及优化内部磷的利用。本文综述了韧皮部蔗糖在转录和生理水平上参与协调植物对磷饥饿反应的证据。
Sugars in plants, derived from photosynthesis, act as substrates for energy metabolism and the biosynthesis of complex carbohydrates, providing sink tissues with the necessary resources to grow and to develop. In addition, sugars can act as secondary messengers, with the ability to regulate plant growth and development in response to biotic and abiotic stresses. Sugar-signalling networks have the ability to regulate directly the expression of genes and to interact with other signalling pathways. Photosynthate is primarily transported to sink tissues as sucrose via the phloem. Under phosphorus (P) starvation, plants accumulate sugars and starch in their leaves. Increased loading of sucrose to the phloem under P starvation not only functions to relocate carbon resources to the roots, which increases their size relative to the shoot, but also has the potential to initiate sugar-signalling cascades that alter the expression of genes involved in optimizing root biochemistry to acquire soil phosphorus through increased expression and activity of inorganic phosphate transporters, the secretion of acid phosphatases and organic acids to release P from the soil, and the optimization of internal P use. This review looks at the evidence for the involvement of phloem sucrose in co-ordinating plant responses to P starvation at both the transcriptional and physiological levels.