Functional Characterization Of A Zinc-finger-like Gene ThZFL From Tamarix Hispida

This study served to isolate a Zinc-finger-like gene(ThZFL) from the Tamarix hispida roots cDNA library in response to salt treatments. The length of the ThZFL gene was 514bp. The gene open reading frame(ORF) was 381bp in length that was from 103 of ATG to 421 TAA. The ThZFL gene encodes a predicated polypeptide of 105 amino acid with a molecular weight off 11.25kDa and a pI of 9.97. Analyzing the gene by bioinformatics indicated the ThZFL gene has low sequence homology to animal Zinc-finger genes.Expression of ThZFL in Tamarix in response to abiotic stress was studied by Northern blot. The results showed that ThZFL was response to treatments of salt and osmotic in T.hispida roots and ThZFL was induced by ABA treatment. Subcellular localization ananlysis showed that the ThZFL protein is localized in the cell wall.The ThZFL gene was inserted into pYES2 and transformed into yeast cells(Saccharomyces cervisiae). Yeast cells transformed and pYES2 empty vector were stressed by different abiotic stresses. The results demonstrated that ThZFL exhibits a wide range of abiotic stresses.To further characterize the function of ThZFL in plant, we transformed ThZFL gene into tobacco by using Agrobacterium mediated transformation.Furthermore, the GUS gene was transform into tobacco as the control.The transgenic lines were examined by PCR,Northern hybridization and Southern hybridization, confirming that ThZFL gene and GUS gene have been integrated int the genome of tobacco, the foreign ThZFL gene and GUS gene were successfully expressed in all the transgenic lines.Based on the above results, tree transgenic lines were selected for investigating the tolerance of abiotic stresses, the GUS gene transgenic line and WT line as contol. Germination percentage of the seeds,relative growth rate and activity of MDA were measured and analysised under different abiotic stresses. The results showed that under abiotic stresses, germination percentage of seeds and relative growth rate in all transgenic lines were higher than that of the control. The MDA content was lower than that of the control. Theses results showed that overexpression of ThZFL in transgenic tobacco increased tolerance to salt and osmotic.