The Study Of J-domain Protein Genes In The Arabidopsis Thaliana

J-protein is a kind of protein which contains J-domain. A total of 94 J-proteins were identified in the genome of the model flowering plant Arabidopsis thaliana, which constitute a super protein family. AtJ72, AtJ70 and AtJ24 are members of the J-protein family in Arabidopsis thaliana. It has not been reported yet to the functions of these there genes. In order to understand the possible functions of AtJ72, AtJ70 and AtJ24 in development and environmental stresses, the phenotypes of AtJ72, AtJ70 and AtJ24 mutants were observed and analyzed during growth and development, meanwhile the responses of the mutants to various environmental stresses were investigated.T-DNA insertion homozygous mutants of AtJ72, AtJ70 and AtJ24 genes were identified by PCR method. Lacking expression of the target J-domain protein was examined by RT-PCR. The results showed that AtJ72, AtJ70 and AtJ24 genes were knocked-out because of the insertion of T-DNA.Under normal growth condition, the phenotypes of AtJ72, AtJ70 and AtJ24 mutants were observed and compared with wild type. The results indicated that there was no obvious difference in growth and development course, such as in the emergence of radicle, corcle and cotyledon, in the time of bolting and flower, between AtJ72, AtJ70, AtJ24 mutants and wild type. There was also no distinct difference in the length of roots, the size of rosette leaves and height of stems and hypocotyls between several mutants and wild type.The mutants of AtJ72, AtJ70 and AtJ24 genes were treated with heat stress, cold stress, freeze stress and salt stress, and so on. The results showed that the viability of AtJ72 mutants was obvious weaker than wild type under salt stresses. However there was no difference under heat stress, cold stress, freeze stress between AtJ72 mutant and wild type. And there was also not obvious difference under heat stress, cold stress, freeze stress and salt stress between AtJ70, AtJ24 mutants and wild type.The binary vector pCAMBIA1300 including the chimeric gene AtJ72-GFP was constructed. Then the binary vector was transformed into Agorobacterium tumefaciens strain GV3101. The positive stains were chosen in order to transform wild Arabidopsis. The transgenic lines were obtained by screening with Hygromycin, and were further identified by PCR amplification of the chimeric gene AtJ72-GFP from genomic DNA of transgenic lines. The root cells of the positive transgenic lines were viewed under Confocal. The result showed that AtJ72 was likely to be located in cell wall or cell membrane.