The Structure And Expression Analysis Of HKT1Gene From Thellungiella Salsuginea

Salt stress is a worldwide problem of the most countries and regions, it has been existedand greatly affects plant growth and development and agricultural production.Thellungiellasalsuginea, a close genus of the model plant Arabidopsis, is a typical halophyte with high salttolerance. Three members of HKT1gene, highly homology with Arabidopsis, were foundfrom sequencing database of Thellungiella salsuginea genome. In this work, the correlation ofmulticopy TsHKT1gene and salt tolerance were studied and the functions of TsHKT1geneswere discussed.The amino acid sequence alignment between TsHKT1s and AtHKT1suggested that thesimilarity between TsHKT1s and AtHKT1was more than80%. The intron analysis showedthat TsHKT1s and AtHKT1all contained2introns, but there is a big difference in the lengthsof the introns between TsHKT1s and AtHKT1. The regulatory elements analysis of TsHKT1sand AtHKT1promoters showed that more cis elements related abiotic stress are presented inTsHKT1s promoters and most in TsHKT1a.The expressions of TsHKT1s and AtHKT1under the condition of salt stress weredetected by RT-PCR and Northern blot.The result indicated that the expression of TsHKT1aand TsHKT1b were up-regulated and TsHKT1c gene was slightly down-regulated. Theexpression pattern of TsHKT1a and AtHKT1under salt stress was analyzed by Northern blotwith separated the root and the shoot.The result indicated that the expression pattern ofTsHKT1a and AtHKT1was evidently different before and after salt stress treatment.GUS histochemical staining of transgenic Arabidopsis shows that TsHKT1a, TsHKT1band TsHKT1c expressed in different tissue and all along period of growth, though the degreeof expression was different. The expression of TsHKT1a and TsHKT1b were induced underNaCl and ABA treatment, while the expression of TsHKT1c was not altered.