Comparative Study On Seedlings Characters In Rol Gene Transfer Poplar

Whether the exogenous genes can be expressed stably is still a significant issue influencing the use of transgenic plantlets. Researches indicated that exogenous genes'experession and stability are associated with their inactivation and silence under many circumstances. This indication that experession and stability of exogenous genes are effected by inactivation and silence resulted in the interaction between enviornmental condition and growth and development of transgenic plantlets. After 6 years of field cultivation and management, whether the exogenous gene expresses well in the transgenic triploid Populus tomentosa containing Ri plasmid planted at 2004 is a generally concerning issue. Ri plasmid contains rol genes which can induce formation of adventitious roots. The transformation of Ri plasmid or one or several rol genes into plants can improve rooting ability of plants. However, some plants exhibited a series of variations, including plant dwarf, leaves wrinkled, internodes shorten, branches increase, which influenced plant growth significantly.In order to study the exogenous gene's expressing variations and stability itself in the adult plant as well as the variations caused by rol genes, we use 6-years-old triploid Populus tomentosa contained Ri plasmid and 1-year-old Poplar 741 contained rolB,rolC genes, compared with the non-transgenic triploid Populus tomentosa and Poplar 741, to identify PCR analysis, the morphological character and grow variation, the content of chloroplast, the character of photosynthesis, the fluorescence and the dynamic of endogenous hormones. Results were showed as follow:It can be proved that the exogenous gene is well exsisting in the Poplar Genome by PCR analysis for the exogenous gene of the transgenic plantlets.Then, what the study of morphological character are showed as follows: At the one hand, among the Ri plasmid tranfer lines, the petiole length,leaf length,leaf width and leaf area of transgenic plantlets are all less than the compared ones, while blade aspect ratio is more than the compared ones; 71 percents of the transgenic plantlets's height is less than the compared ones; 81 percents of the transgenic plantlets's height of 1.3m is less than the compared ones; However, the section spacing is irrelgular.At the another hand, among the rol gene tranfer lines: the petiole length, leaf length, and leaf width of the rolB gene tranfer lines are more than the compared ones, but the leaf area is nearly the same; Then, the most of the rolC gene tranfer lines'petiole length and leaf length are less than the compared ones, as the leaf width is the same. It can be seen that the blade aspect ratio of rolB ones is slightly more than the compared ones, as the rolC ones is significantly longer. When it mentions the leaf area of the rolC ones, just C-8 and C-18 are slightly larger.Among the 1-year-old Poplar 741 contained rolB,rolC genes, B-9 and B-13 are higher than the compared ones; the rolC gene tranfer lines are all shoter. The rolB gene tranfer lines'diameter is more thicker than the control group, while the rolC gene tranfer lines'is opposite, and their section spacing is smaller than the control group, as rolB's is larger than the rolC's.Chlorophyll content, photosynthesize character of function leaves and fluorescence of transgenic strains were measured. Results showed as below: Chlorophyll a and a+b content of the control group strains is more than that in the Ri plasmid tranfer lines. Chlorophyll a,b and a+b in rolB strains were higher than that in compared strains, meanwhile it is higher than the rolC strains. The net photosynthesize rate of rolB and rolC strians are all lower than most of the compared strains, as the net photosynthesize rate of rolB strains was higher than rolC. The value of Fv/Fm of the Ri gene tranfer lines, the rolB strains, the rolC strains is lower than their own control group; Then, the value of PI of the Ri strains and rolB strains is also lower than their compared strains.Endogenous hormones in leafs were measured through HPLC method, we can conclue that most of the content of endogenous GA3 in Ri strains,the content of endogenous IAA of all strains,the content of endogenous ABA of a part of strains and the value of endogenous IAA/ABA are all higher than the control strains. In the rol strains, the content of endogenous GA3 of most strains was showed a slightly rise than the compared strain, but it is irregluar between rolB strains and rolC strains; All the strains'endogenous IAA's content is higher than the conpared strains, while the rolB's is higher the rolC's; Most of the strains'endogenous ABA's content is lower than its cotrol group, while it is irregular between rolB and rolC; And all the transgenic plants'value of IAA/ABA is higher than its control group's, and it is irregular between rolB strains and rolC strains.