The Cloning And Molecular Characterization Of SlNAC2in Suaeda Liaotungensis K

The plant-specific NAC (NAM、 ATAF1/2、 CUC) transcription factors play importantroles in plant development and stress responses.Suaeda liaotungensis K. grows in the seaside, and perennial subjects to abiotic stressessuch as high salt, low temperature, but still has strong vitality, indicating S. liaotungensis K.has a lot of salt tolerance genes. For most area of northern China suffered abiotic stresses suchas salt, low temperature and drought, resulting in crop yields decline, even extremely.Therefore, mining the salt tolerance genes in S. liaotungensis K. and providing them for plantgenetic engineering are very necessary.A NAC EST was identified from high-throughput Solexa sequencing platform of S.liaotungensis K., and named SlNAC2. We used RACE to amplify the full-length1458bpcDNA of SlNAC2(GenBank No.KC460341). Its largest open reading frame contained906bp,encoded301deduced amino acid residues with a calculated molecular weights of34.3kDaand a predict of pI7.04. SlNAC2was classified as ATAF subfamily by built systematic treeand multiple sequence comparison of amino acid sequences of SlNAC2with other NAC proteins.Initial speculation SlNAC2responses to biotic and abiotic stresses.We used qRT-PCR method to analysis the tissue characteristics of SlNAC2and theexpression of SlNAC2under salt, drought, low temperature and ABA stress. SlNAC2geneexpressed different patterns in various tissues under normal condition. Leaves was the highest,lower in stems, the lowest in roots. The expression of SlNAC2gene increased first and thendecreased under salt, low temperature, drought and ABA stress. So SlNAC2gene is astress-induced gene.The distribution of SlNAC2-GFP was examined in onion epidermal cells by usingfluorescence microscopy. Subcellular location assay showed that SlNAC2protein wastargeted to the nuclei. The transcription activation assay in yeast demonstrated that SlNAC2had the transcription activation activity. SlNAC2is a transcription factor.We obtained SlNAC2transgenic Arabidopsis of T2generation by the floral dip method.Transgenic experiment indicated that the ability to resist salt stress of SlNAC2transgenic lineswas stronger than the wild type and pBI121-GUS transgenic plants. Therefore, SlNAC2gene plays a certain role in resisting salt stress in plants.