Isolation And Expression Analysis Of ZFP Genes From Eucalyptus Grandis And Screening Of Transcription Factors From The Promoter Of EgrZFP1

C2H2-type zinc finger proteins are a major family of transcriptional factors and play a crucial role innot only plant growth and development but also plant response to stresses. In plants, the first C2H2-typezinc finger gene was isolated in Xenopus tropicalis, named ZPT2-1, and genes of this type zinc fingerprotein have gradually been isolated from Arabidopsis thaliana, cotton, soybeans, rice and other plants.Lots of them have been identified in herbaceous plants but few were clarified in woody plants.Seven genes with two zinc finger motifs were isolated from Eucalyptus grandis by homologous,named as EgrZFP1-7. They all belonged to Q-type C2H2zinc finger gene family and were classifiedinto subclass C1, containing a QALGGH motif. Except EgrZFP2, all of them contain an EAR motif.Expression pattern of EgrZFP1-7genes showed that no obvious expression change was found inleaves, stems and roots except EgrZFP4, which had higher transcripts level in roots than in leaves andstems and EgrZFP6, which had lower transcripts level in leaves than in roots and stems. When treatedwith different abiotic stresses, expression of EgrZFP1-7were induced by low temperature,2C or4C was the optimal temperature for increasing the transcripts level of EgrZFPs. Time course ofEgrZFPs at4C for2h,4h,8h,24h and48h revealed EgrZFP1-6reached the highest level after48htreatment while EgrZFP7showed the transient expression pattern. Salinity (NaCl,200mM) alsoincreased expression of EgrZFP1-6, but inhibited EgrZFP7. All seven genes exhibited no response toABA (100μM), implicating they were independent to the ABA stress responding pathway. The resultsindicated that EgrZFP1-7are involved in cold and salt tolerance in Eucalyptus grandis, via aABA-independent way.Some transcription factors binding to the promoter of EgrZFP1were isolated by yeast one-hybridexperiments. The main TFs are as follows: transcription factor NAC with NAM domain,β-galactosidase, ATPase, aquaporin, Photosynthesis protein and two protein without annotation. Theexpression analysis of gene P3-1,4,5shows that gene P3-1that was translated to NAC wasupregulated by cold and salt stress, while its expression level was no obvious change by ABA anddrought treatment. Gene P3-4,5were upregulated by drought stress, while its expression level was noobvious change by ABA, cold and salt treatment. The results indicated that the three genes are involvedin abiotic stress tolerance via a ABA-independent way.