The Functional Research On CbTIP

Research on cold resistant of plant has been a hot topic,Chorispora bungeana lives in the periglacial areas with complex and changeable environment and it is also an ideal material for plant adaptation mechanism study.Here,we conducted the experiment with Chorispora bungeana as material,use Real-time PCR?Yeast two-hybrid to investigate the function of CbTIP.Results were showing below:1.The full length of CbTIP was 1073bp containing a 108bp intron and a 759bp open reading fiame which encoded a deduced protein with 253 amino acids.Sequences allignment indicated that CbTIP was 90.87%indetical to AtTIP1-2(a member of tonoplast intrinsic protein).Bioinformatics analysis illustrated that this deduced protein contained six transmembrane sequences and two conserved NPA motifs.Two possible phosphorylation sites located in the position of Thr 55 and Trp 252.2.Subcellular localization dialysis indicated that CbTIP localized on cytoplasmic vesicles and change position along with cytoplasmic flow.This showed that CbTIP might involve in the materials transportation and metabolism of cell.3.Then,expression pattern analysis demonsttrated that CbTIP mainly expressed in roots compared with flowers and leaves of Chorispora bungeana and the expression level was up-regulated under cold?salt and drought stress,which indicated that CbTIP gene might participate in protecting Chorispora bungeana from abiotic stress.4.Compared with Arabidopsis(Columbia),overexpressing CbTIP homozygous line showed more sensitive to mannitol,salt and ABA on seed germination.Meanwhile,water loss rate and relative water content showed much difference and there was on difference between proline and relattive conductivity rate.This demonstrated that CbTIP might played a role in water transportation during and seed germination.Yeast two-hybrid experrinents screened two proteins that interacted with CbTIP respectively,one was homology with Arabidopsis At2g44370(cysteine/histidine-rich C1 domain-containing protein)and the other was At3g56460(GroES-like zinc-binding alcohol dehydrogenase family protein).At2g44370 mainly expressed in guard cells,hypocotyl and root with a disulfide reduction activity and AT3g56460 have oxidoreductase activity which expressed in almost all tissues.In summary,CbTIP is the first aquaporin cloned from C.bungeana and we confirmed that it involved in a variety of abiotic stress resistence,provideing a new perspective for the adaptation to extreme environments of C.bungeana.CbTIP probably played a critical role in seed germination and water balance within cells.The proteins that interacted with CbTIP might help plants survive in abiotic environments.