Sequencing And Analysing Of Haloxylon Ammodendron Transcriptome And Cloning Of SNAC Subfamily Under Drought

Haloxylon ammodendron is a kind of sand-fixing plant, not only can prevent land desertification and maintain the balance of environment-ecological, but also can grow in extreme environment. It is important to make the molecular mechanism of Haloxylon clear,which makes a great value to grow the strong-stress-tolerance transgenic plants and understand molecular mechanisms of stress resistance network. Currently, the research is still limited in physiological and biochemical and research about molecular is still in infancy stage.In this study we sequenced the transcriptome of Haloxylon and constructed a transcriptional information platform. The gene expressions before and after drought stress in different tissues were screened out by comparing Haloxylon transcripts between control and drought group.Based on results of the sequencing data annotation, the Haloxylon transcription factors which were noted as NAC, bZIP, MYB, WRKY were grouped and preliminary analyzed by Bioinformatics method. Finally six SNAC subfamily genes were cloned, we compared the sequences obtained by cloning and Unigene sequences in transcriptome to verify the quality of sequencing and splicing, also laid a foundation for further study on Haloxylon stress resistance mechanism.The results are as follows:(1) 41,381 Unigenes were obtained after transcriptome sequencing and original sequences assembling. There were 2430 upregulated genes in assimilation branches, 4349 upregulated genes in roots and 996 upregulated genes in both stems and roots after a comparative analysis between normal and drought groups about Haloxylon Transcriptome sequences. This proved that there existed a number of genes which response drought stress in different ways.(2)We analyzed the four kinds of transcription factors(NAC?bZIP?MYB?W RKY) in Haloxylon, grouped these family members with a classification of Arabidops is and rice as reference and defined their position on the evolutionary relationships. A ccording to the gene function of Arabidopsis, rice and other plants which had been ve rified and binding with the changes of gene expression in transcription levels before a nd after drought stress, functions of different subfamily genes in Haloxylon were spec ulated. HaNAC02/03/04/06/20/22/23/24/27/35/42 in Haloxylon NAC gene family, HabZI P3/4/5/6/13/14/16/17/20/22/24/26/27/28/29/31 in HabZIP gene family, HaWRKY2/4/5/6/7/8/11/13/14/15/16/17/18/19/20/21/22/24/25/26/27/28 in WRKY gene family and HaMYB2/6/8/10/11/12/13/14/15/18/20/25/35/43/44 in MYB gene family may involved drought str ess response in different ways or pathways.(3)Four full length Haloxylon NAC family genes(HaNAC20/22/24/27) were cloned and were highly consistent with the Unigene sequences.That means the Haloxylon Transcriptome has a good assembly quality. The full-length sequences which had been cloned were preliminary analyzed by Bioinformatics method.