植物抗寒及其基因表达研究进展

植物经过逐渐降低的温度从而提高抗寒能力 ,这个过程被人们称为低温驯化。植物低温驯化过程是一个复杂的生理、生化和能量代谢变化过程 ,这些变化主要包括膜系统的稳定性、可溶性蛋白的积累和小分子渗透物质 ,比如脯氨酸、糖等 ,这些变化中的一些是植物抗寒必需的 ,而另外一些变化不是必需的。主要对冷害和低温生理生化变化、低温诱导表达基因的功能和作用、低温驯化的调节机制及其信号转导方面进行了综述。通过差别筛选 c DNA文库的方法已经鉴定了许多低温诱导表达、进而提高植物抗寒能力的基因 ,其中有脱水素、COR基因和 CBF1转录因子等。低温信号的感受、转导和调节表达是低温驯化的关键环节 ,低温信号的转导过程与干旱胁迫之间具有一定的交叉 ,这为利用 ABA等来提高植物抗寒能力成为可能 ,相信不久的将来人们可以通过提高植物抗寒能力从而增加经济产量成为现实。

Plant freezing tolerance and genes express in cold acclimation: a review

In plants, freezing tolerance increases upon exposure to low temperatures, which is known as cold acclimation. Cold acclimation in plants is a complex process involving physiological, biochemical and energetic changes. These include membrane stabilization, the accumulation of soluble proteins, and small penetrable molecules such as proline, sugars and etc. Some of these changes are essential for plants to survive freezing temperature, whereas the others are not. Recent advances in understanding the physiological and biochemical changes upon freezing injury and exposure to low temperature, characterization and functions of low-temperature-induced genes, and the mechanisms including gene regulation by low temperature and signal transduction are reviewed.By differential-screening cDNA library, many genes that are induced by low temperature to improve freezing tolerance in plants have been identified and characterized, such as dehydrins, COR genes and CBF1 factor. The sensing, transduction and the regulation of cold signals are the key stages in cold acclimation. There are also come cross-talks between cold acclimation and drought stress in signal transduction, which makes it a potential application to use ABA to increase plant freezing tolerance. In near future, plant productivity may be increased by improving freezing tolerance.