The Expression Of Poptr;CYCD1;1 From Poplar And CYCD1;1, CYCD2;1, CYCD3;1 From Arabidopsis Thaliana In Nicotiana Tabacum

Cell division is one of the basic characteristics of organisms, which plays an extremely important role in the process of plant growth and development.Cell cycle and growth regulation can not be separated from a class of important cell division control factors--cyclins. CYCD1;1, CYCD2;1, CYCD3;1, as a regulatory factor, has been identified in regulation of cell cycle. In order to address the functions of CYCD, the Poptr;CYCD1;1 from Populus and AtCYCD1;1, AtCYCD2;1, AtCYCD3;1 from Arabidopsis were introduced into Nicotiana tabacum. The main conclusions are as follows:1. pER8-GFP was constructed and was transformed into tobaccos.The transgenic plants were induced with different concentrations and different times of estrogen. The expression of Poptr;CYCD1;1 in transgenic tobacco was tested by using qRT-PCR and NightSHADE plants in vivo imaging system, and the results showed that the GFP gene appeared in the hypocotyl and root tip cells of tobacco. It showed that the XVE chemical induction system in tobacco could also be used to control the expression of target gene efficiently by the induction of estrogen.2. pER8-Poptr;CYCD1;1 and pER8-Poptr;CYCD1;1-RNAi was constructed and transformed into tobacco. The tobacco plants were treated by estrogen, and there were significant differences between the transgenic and wild type, with increased length of the style, larger of petal and ovary. When pER8-Poptr;CYCD1;1-RNAi was introduced into 35S::Poptr; CYCD1.1 tobacco, some lines showed low expression level and exhibited restoration of phynotype. These results showed that the overexpressing of Poptr; CYCD1.1 and resulted in the changes of phenotype in transgenic lines.3. AtCYCD1;1, AtCYCD2;1, AtCYCD3;1 were constructed into pROKII vector and transformed into tobaccos. The results of qRT-PCR showed the mRNA of AtCYCD1;1, AtCYCD2;1 and AtCYCD3;1 were transcribed in transgenic tobaccos. There were significant differences in the flowers between the transgenic and wild type, with increased width of the corolla, length of petal, sepal and seed pod, which suggested the overexpression of AtCYCD1;1、AtCYCD2;1、AtCYCD3;1 had an obvious influence on the development of transgenic tobacco.4. Compared with the wild type, the transgenic plant overexpressing AtCYCD3;1 showed altered transcription levels of s NtICK、NtCDK and NtCDKC. The root tip cells of transgenic plants were smaller, the stems were curved, the leaves were curled, and the seeds became smaller. The paraffin test of transgenic pROKⅡ-AtCYCD3;1 tobacco in crooked stem section showed the number of cambial cells and xylem cells of transgenic plants in the bent part was more than that of wild type, Also, freehand section of stems with phloroglucinol-HCl staining showed xylem cells increased in transgenic tobaccos and wild type, indicating that AtCYCD3;1 gene overexpression may effect the cell division and accelerate the lignification process of cell walls in transgenic tobaccos.