Expression Of PtAUX1Gene In Populus Tomentosa Carr. And Transformation In Poplar

Populus tomentosa Carr. as one of the quick growing species of trees is popular in the world. The rich genetic resources has asexual reproductive and burgeon ability. Populus tomentosa Carr. which has short rotation cycle is popularization with biological sources of energy in the future. In addition, it is the model plant in biology study of wood plants. Populus tomentosa Carr. is the third plant that has been assayed the whole genome sequence after Arabidopsis thaliana and Oryza.sativa L.. Populus tomentosa Carr. is first specie of the perennation wood has been assayed the whole genome sequence.Auxin induce detached stem and coleoptile segments to extend fast is one of the notable and rapid hormone reaction in the plants. Auxin involves many growth and development processes of plants, study of auxin polar transport and signaling is useful to indicate life mechanism. My laboratory constructed vector PtAUXl, has transformed into Populus tomentosa Carr. and studied the gene function. Transgenic plants were confirmed by RT-PCR, phenotypes and detached leaves of transgenic plants and morphologic characters cultured were analyzed.Through the Southern hybridization test, the three positive plant systems were detected strong hybridization signal, this means that the transformation of the auxin influx carrier gene PtAUXl was constructed successfully. Transgenic plants were confirmed by RT-PCR, bud, spire and radicle were all expressed.We got the best condition for mulberry leaf transformation through optimizeing genetic transformation system in Populus tomentosa Carr.. The best nutrient medium for adventitious bud differentiation is MS+IAA (0.25mg/L)+6-BA (0.25mg/L)+ZT (0.25mg/L) and PH is6.0. When2cm length, adventitious bud is inoculated in MS nutrient medium to take root. The ratio for Cytokinin and auxin in MS nutrient medium is between2-5:1, adventitious root can be induced. The leaves of Populus tomentosa Carr. are sensitive to Kan,50mg/L is the critical value in expanding propagation, taking root and screening the genetic plants. The transformation efficiency is the best when strain LBA4404is selected. And when consistence OD600index in0.4and15min infection is the best efficiency. During the operation of the genetic transformation,2days’ preconditioning explant and2days’ darkness culture and AS (200μmol/L) inducer can increase conversions. Overexpressing35::PtAUX1in Populus tomentosa Carr., the genetic plants are in vigorous growth, leaves increase and length growth. When the genetic plants in low light condition, the plant height is2-3times as wild plant. In addition, the genetic plants are better than wild plants in leaves of colour, size, thickness and amount. When operate RT-PCR in genetic plants in low light condition, different times and different parts in Populus tomentosa Carr. of PtAUX1is different, the susceptibility of light condition is lower than wild plant.All these result reveal initially the function of PtAUX1, confirm it is important for auxin in the process of plant growth and development. It is general expression of PtAUX1in the organs. It coincident with its candidate function in distributing auxin through plants as an auxin influx carrier. This text is Populus tomentosa Carr. as an object of study, discuss the function of the auxin influx carrier in the process of growth and development.