糖在松树体内长距离运输的生化分析与分子机制研究

The growth of a tree relies on its ability to distribute carbon (sugars) produced by photosynthesis efficiently and rapidly along the entire length of its body. The transport of sugars takes place in the phloem vascular system, where a concentrated sugar solution moves at speeds far exceeding that of diffusion. How this happens in conifers, which can reach heights of more than 100 m, remains a mystery. .While recent publications illustrate how a single sugar concentration gradient between source and sink organs drives phloem transport in broad-leaved trees (angiosperms), the available data suggests that an alternative mechanism must exist in conifers (gymnosperms). .In this project, we will fully characterize the mechanism of long-distance translocation of sugars in the phloem vascular system of conifers. To succeed, we will follow a cross-disciplinary approach, combining biochemical techniques and molecular biology with radiology, mathematical modeling and microfluidics. Experiments will be conducted on multiple species, including Pinus massoniana, one of the 5 most planted trees in China. Understanding how conifers can allocate carbon in a controlled fashion and with high efficiency over tens of meters will be highly significant for breeding programs that aim to increase tree productivity.

植物生长依赖于光合作用合成的碳水化合物从源器官到库器官的快速运输和有效分配。糖在植物体内通过维管系统的运输速率远高于其扩散速度，但糖运输的分子机制仍不清楚。目前的研究结果表明，被子植物阔叶树木的源器官和库器官之间的单糖浓度梯度能够驱动糖在韧皮部的运输，而糖在裸子植物松树中则利用其它尚不明确的运输机制进行运输。本课题将运用生物化学、分子生物学、数学建模及微流控芯片技术，以已经测序的马尾松和挪威云杉为材料，解析糖在松树体内长距离运输的生化与分子机制。本研究不仅将在理论上阐明糖在被子植物松树中运输的分子机制而且也将为松树分子育种奠定理论基础。

植物生长依赖于光合作用合成的碳水化合物从源器官到库器官的快速运输和有效分配。糖在植物体内通过维管系统的运输速率远高于其扩散速度。本项目探究了糖如何在高度可超过百米的针叶植物中进行运输。我们运用了生物化学、分子生物与放射学、数学建模以及微流控芯片技术等方法，在不同的物种中进行实验，其中包括中国五大栽种树种之一的马尾松。我们鉴定并表征了相关的蔗糖转运蛋白。研究结果表明，针叶植物树干的主动跨膜转运促进了蔗糖的快速转运。另外，我们发现叶片中的水通道的形成增加了整株植物蔗糖分配的效率。该研究阐明了针叶植物如何以受控的方式在几十米的长距离高效地进行碳分配，对以增加树木生产率为目的的树木育种具有非常重要的意义。