Studies On Screening Cold Resistant Genes Of Hevea Brasiliensis Using CDNA Array

In China, the rubber tree are mainly cultivated in the region at 18°-24°N, which is the north of rubber cultivating area in the world. Recently years, the growth and yield of rubber tree was serious affected by cold climate. So the first work to do in rubber tree breeding is that how to screen the cold resistant strains. Transcription factors can activate a cluster of genes expression to response the cold stress. In the research of cold response in plants, only the CBF pathway of Arabidopsis was clear and published, while the expression and regulation mechanism of cold resistant gene in the cold response regulatory networks is unclear, which is the limitation of cold resistant breading.It is development rapidly that using the molecular biology technology to improve cold tolerance, drought resistance of plants. In this research, we used the method of cDNA array to screen the genes response the cold stress from the cDNA library of rubber tree. The relationship of these genes and its function were analyzed. The main results were summarized as follows:1. In total,84 genes were differentially expressed under cold stress, and 21 had different expression in cold resistant and sensitive cultivars.We obtained parts of genes up-regulated expressed to response the low temperature, which were related to metabolism pathway or cellular processes or signal transduction, and we obtained the basic gene expression profile of rubber tree induced by low temperature.2. Further analyzed and screened some differentially expressed cold tolerant genes at low temperature, which were transcription factors(Zinc finger protein gene、MYB)、protein synthesis and degradation related Ubiquitin、26S proteasome, mitochondrial substrate carrier family protein, galactose-1-phosphate uridyl transferase.3. In this study, also detected several "hypothetical proteins" and the unnamed proteins, which were up-regulated or down-regulated expression to response the cold stress. These genes may be performed the important biological function we don’t know, and some proteins probably play an important role to response the abiotic stress.4. This paper used high-throughput gene chip technology to analyze the expression pattern of rubber tree by cold stress at the level of transcription and preliminarily analyzed up-regulated genes. The results make it possible to study the molecular mechanism of cold stress and clone a large number of cold-related genes of rubber tree, and finally cultivate the cold tolerant rubber tree strain.