西藏大花红景天RcCATs 与RcSODs 基因克隆及功能分析

In order to explore the role of catalase (CAT) and superoxide dismutase (SOD) inplateau environment adaptation of Tibet Rhodiola crenulata, the RcCATs gene family membersand RcSODs gene family members were analyzed by bioinformatics and real-time quantitativePCR. Spot assay was conducted to study the responses of yeast cells expressing the RcCAT andRcSOD1 genes under abiotic stress. Yeast two-hybrid was conducted to screen interacting proteinsfrom Arabidopsis yeast library respectively by constructing bait vectors of RcCAT and RcSOD1.The results were as follows: (1) There were two CAT genes, three SOD genes, and Cu/Zn SODcopper chaperone gene (RcCCS), six genes held high sequence identity (66.37%-94.51%) withother homologous species. All genes had no transmembrane domain and held multiplephosphorylation amino acides. Subcellular localization predicted that RcCATs located inperoxisoma, RcSODs and RcCCS located in cytoplasm or Mitochondria. (2) qRT-PCR analysis showed that RcCATs and RcSODs were constitutively expressed in three organs like root, stem andleaf and held the high expression levels in leaf, and all genes expression levels could also beregulated by low temperature and plant hormones (ABA). RcCAT was significantly up-regulatedunder cold treatment condition with the highest expression in leaf more than two times higher thanroot. RcCAT, RcSOD2, RcSOD3 and RcCCS expression patterns were similar under ABAtreatment condition. (3) In addition, spot assay showed that the recombinant RcCAT and RcSOD1yeast cells showed a higher cell viability than the pYES2.0 yeast cells in under cold, hot, NaCl,Na2CO3, Co2+, and H2O2. (4) The pGBKT7-RcCAT and pGBKT7-RcSOD1 bait plasmid withouttoxicity and auto-activation were constructed to perform yeast two-hybrid screening, then foursignificant interactional genes with RcCAT were screened, which were AtbHLH121 (AT3G19860),AtCPCK2 (AT2G23070), AtGRP4 (AT5G50750) and AtRAPTOR1B (AT3G08850). Total threesignificant interactional genes with RcSOD1 were screened, which were AtEMB (AT5G11890),AtMBP2 (AT1G52030) and AtRH8 (AT4G00660). These results illustrated that RcCATs andRcSODs could play an important role in regulating growth and promoting resistance toenvironmental stresses in Tibet Rhodiola crenulata, and laid the foundation for in-depth study ofthe adaptive mechanism of Rhodiola crenulata with plateau environment.