Study On Physiological And Biochemical Characteristics Of The Transgenic Malus Robusta With LeIRT2

The transgenic plants in Malus robusta with LeIRT2 were selected as the research matierials, and the non-transgenic plants in Malus robusta was compared, the study on the effects of LeIRT2 on the tissue culture response, the contents of endogenous hormone and the absorption of the mineral elements in Malus robusta was carried. The main results are presented as follows:l.The tissue culture response including proliferation, leaf regeneration and lateral rooting in transgenic Malus robusta plants with LeIRT2 were conducted under the best conditions of non-transgenic plants. The results showed that the abilities of proliferation, leaf regeneration, lateral rooting in transgenic plants were significantly weaker than that in non-transgenic lines. The survival rate of tissue culture seedling of transgenic plants was significantly higher than that of non-transgenic plant under different environmental temperatures of 22℃and 13℃; the survival rate of tissue culture seedling of transgenic plants was relatively lower under the average temperature of 30℃;while the survival rate of tissue culture seedling of transgenic plants was highest under the average temperature of 13℃.2.Under different concentrations of exogenous IBA,the content of endogenous IAA, ZR in shoot tip and roots of the transgenic Malus robusta plants with LeIRT2 as while as the non-transgenic plants were detected with the method of ELISA. The results showed that the content of IAA and ZR in shoot tip of the transgenic plants are significantly higher than that of the non-transgenic plants under IBA-free conditions.The content of IAA in shoot tip and shoots of the transgenic plants was significantly higher than the compared plants. Under different IBA concentrations, The content of ZR in shoot tip and roots of the transgenic plants are inconsistent.3. The transgenic Malus robusta plants with LeIRT2 were selected for further study. The contents of Ca, Mg and Ni in leaves and roots of the transgenic lines and non-transgenic plants were detected with the method of ICP-AES. The results showed that with the iron concentration of 1μM the content of Mg in leaves decreased sharply of which increased notably in roots,compared with the non-transgenic plants. At the same concentration,the content of Ni in roots was significantly higher than that of the compares, while with no obvious difference in leaves. There were no significant difference of the Ca content in roots between the transgenic and wide plants treated by iron with concentration of 1μM or 10μM. There were no markbal difference of Ca,Mg content in leaves or roots under iron-free conditions.