Tissue-Specific Expression Of Gene Encoding Peptides Hormone In Arabidopsis And The Gene Response To Jasmonic Acidandsalicylic Acid

AtPROPEP gene family has seven members and encods endogenous peptide hormone. Expression of the AtPROPEP gene family members by peptides derived from the C terminus of each gene is very important, can be recognized and binded by two homologous kinase receptor AtPEPRl and AtPEPR2,and cause downstream reactions. However, so far tissue specific expression for each member has not been studyed.In this experiment, we cloned six promoters including AtPROPEPl,AtPROPEP2, AtPROPEPS, AtPROPEP4, AtPROPEP5 and AtPROPEP6 into the binary vector pORE R1 respectively and got Promoter AtPROPEP::GUS individually. Previous studies have shown that AtPROPEP7 transcription has not been found in Arabidopsis. Through Agrobacterium infection wild-type and multi-generation screening, we got Arabidopsis T3 genetically modified seeds stably expressing Promoter AtPROPEP::GUS. β-glucuronidase-based histochemical staining of these seedlings from T3 transgenic seeds were analyzed and we found that AtPROPEP1 and AtPROPEP4 were expressed mainly in root tips, AtPROPEP2, AtPROPEP3 and AtPROPEP6 were expressed in leaves and roots; AtPROPEP5 expressed only in the leaves. With jasmonic acid and salicylic acid treatments performed, we discover that JA promotes expression of AtPROPEP2, AtPROPEP3, SA promotes expression of AtPROPEP1,AtPROPEP2,AtPROPEP3,AtPROPEP4, and both of inhibiting the expression of AtPROPEP6. We also cloned AtPROPEP3, AtPROPEP4 coding sequence into the binary expression vector pRI101 and form 35S::AtPROPEP3,35S::AtPROPEP4 fusion genes. Then, we obtained T3 transgenic seeds. Comparing the phenotype of Col-0 and above-described transgenic material on MQA medium, we found a significant increase in transgenic seedlings root than Col-0. This study reveals tissue specific expression of AtPROPEP gene family and the different responses for hormones. In addition, this reearch also discloses that AtPROPEP3,AtPROPEP4 have the function of promoting root growth in Arabidopsis.