植物对磷饥饿的反应研究进展

磷是构成生命的重要元素之一,也是土壤中有效性最低的一种营养元素。我国是世界上最大的小麦生产国。但是我国耕地中有59%的土壤缺磷。农作物的产量常受到缺磷的影响而受损。土壤缺磷并不是土壤中总磷量低,而是土壤中可供植物直接吸收利用的有效态磷含量低。植物在磷饥饿时会发生各种各样的变化,以尽最大可能满足自身对磷的需求。植物对缺磷的反应是一个复杂的网络过程。大约有100多个基因参与了植物对缺磷的反应。其中主要的有磷转运蛋白基因、核糖核酸酶基因、磷酸酶基因等。植物在吸收外界的磷的过程中磷转运蛋白发挥了重要作用。植物磷转运蛋白基因按照序列相似性可以划分为H+/Pi共转运家族(Pht1家族)和Na+/Pi共转运家族(Pht2家族)。按照吸收动力学的标准可以分为高亲和力磷转运蛋白和低亲和力磷转运蛋白两种。磷饥饿时植物对磷吸收能力的增强的原因之一是增加了磷转运蛋白分子的合成数目。目前尽管人们对植物吸收磷的理解已经有了长足的进步,但是在植物对磷的具体调控机制、磷的跨液泡膜运输等重要方面仍然没有明确的结果。

Advances in Research on Plants' Reactions under Phosphate Starvation

Phosphate is one of the most important elements needed by all of the lives. Meanwhile, it is also one of the least available nutrients in the soil. China is the largest wheat-production country. But about 59% soils in China is phosphate deficient. The yields of the crops are always affected by phosphate starvation. In fact, the total phosphate in soil is not deficient. But the available phosphate by crops is not enough. Under the condition of phosphate starvation, many changes took place in plants to adapt the bad condition. More than 100 genes took apart in the process, including phosphate transporters, RNases and phosphatases and so on. Phosphate transporters were one of the most important families. According to the sequence similarities, phosphate transporters can be divided into Pht1 family and Pht2 family. Phosphate transporters can also be divided into low-affinity phosphate transporters and high-affinity phosphate transporters due to the uptake kinetic properties. Plants can increase their capacity for phosphate uptake during phosphate starvation by synthesis of additional transporter molecules. Although many advances had been achieved in plant's reaction to phosphate starvation, some fields such as the concrete regulation mechanism of plant's reaction to Pi deficiency, the Pi transportation across tonoplast are not clear until now.