TabZIP Transferred White Poplus Simonii×P. Nigra Generation And Stress Resistance Analysis

In this study, using agrobacterium-mediated transformation to import the transcription factor gene TabZIP (Tamarix hispida basic leucine zipper) from extreme drought, salt-tolerant plants Tamarix. Cloned gene TabZIP was transformed into pollen of the Poplus. simonii×P. nigra genome. Under salt stress treatments, heavy metal treatments and drought stress treatments, we compared the resistant of transgenic and non-transgenic P. simonii XP. nigra.Three kanamycin resistant buds were obtained from genetic transformation of P. simonii×P. nigra pollen plants. After being confirmed by PCR, the results all showed positive; after being confirmed by qRT-PCR, the results showed that the target gene express in three lines. These indicated exogenous gene expression at the RNA level. After;Western hybridization analysis on the three transgenic lines, the results showed that the transgenic lines had TabZIP resistance antibody specific hybridization bands at16.5Ku. These indicated that three transgenic P. simonii×P. nigra tissue cells had protein products of TabZIP expression.Three transgenic lines were carried out on NaCl stress, heavy metals and drought stress treatments, then compared indices such as high growth, leaf number, injury index, and root growth and somaclone leaf differentiation of budding rate, leaf damage index after the salt stress treatments between transgenic and non-transgenic P. simonii×P. nigra plantlets. The results showed that after rootless plantlets were treated with0.8%NaCl for20days, each transgenic lines either relatively high growth or rooting index were significantly greater than non-transgenic lines, except the number of leaves with no significantly differences. The damage index of transgenic lines were significantly less than the non-transgenic lines, the relative growth rate of control was11.6%, the average relative growth rate of transgenic P. simonii×P. nigra was84.8%, the rooting index of transgenic P. simonii×P. nigra was1.64times higher than the control, harm index compared to controls that decreased by71.4%. After tissue culture seedling of transgenic lines under the treatment of0.6%NaCl, budding was21.3%higher than control, and leaf injury index was60.2%smaller than control. Above results showed that salt stress conditions, injury rate of transgenic P. simonii×P. nigra was significantly less than control, the ability of the salt resistance was improved.After treated with0.2mmol/LCu2+for30days, average height of transgenic P. simonii×P. nigra was31.1%higher than controls, the relative growth was6.1times significantly greater than controls, the number of leaves was32.7%significantly larger than controls, the damage index was29.8%significantly smaller than controls. Transgenic lines exclude TB3were significantly higher than controls on rooting index, and average rooting index was1.93times larger than controls. TabZIP gene enhanced P. simonii×P. nigra resistance to heavy metal stress.After rootless plantlets were treated with5%PEG6000for30days, average height of transgenic P. simonii×P. nigra was18.7%higher than controls, relative growth was significantly greater than controls. TB3had the smallest average number of leaves,6.77, then control was7.33, TB1and TB2were8.33and8.50respectively. Injury index of transgenic lines was29.6%smaller than controls, and average root length was2.78times longer than controls, rooting index was greater than control. The above results indicated that TabZIP gene also could improve drought tolerance of P. simonii×P. nigra.According to above results, TabZIP gene expression could improve salt tolerance, resistance to heavy metals and drought stress of transgenic P. simonii×P. nigra. Line TB2had the strongest resistance, and TB3was the strongest but one. The resistance of TB1was significantly higher than the non-transgenic control.