Cloning And Functional Analysis Of PeGA20ox1 Gene Related To Height Growth In Phyllostachys Edulis

Moso bamboo(Phyllostachys edulis),is one of the most important economic bamboos in China.As a high-quality renewable resource,bamboo can be produced into board,paper and various bamboo handicrafts,which accounts for a large proportion of the economic income of bamboo forest.Bamboo have a very special height growth characteristic--“jointing growth”,but nowadays there are only few researches about genes involved in height growth.Gibberellin 20 oxidase(GA20ox)enzymes play an important role in plant high growth by regulating gibberellin synthesis.In this study,PeGA20ox1,an orthologous gene of Os GA20ox1,belonging to GA20 ox gene family,was selected and cloned in Phyllostachys edulis.And its functional analysis may also provide a glimpse about the height growth mechanism of Phyllostachys edulis.1.For GA20 ox genes prediction in moso bamboo,GA20 ox amino acid sequence from Arabidopsis thaliana,Oryza sativa,Populus trichocarpa,Zea mays and Brachypodium distachyon were used as query sequences to blast in moso bamboo database.As a result,7GA20 ox genes in Phyllostachys edulis contained a complete conserve domain were identified,which were named as PeGA20ox1,PeGA20ox1-like,PeGA20ox2,PeGA20ox2-like,PeGA20ox3,PeGA20ox4 and PeGA20ox4-like.Conserved domain analysis showed that those genes both had 2OG-Fe II＿Oxy and DIOX＿N domain and were the typical GA20 ox genes.The phylogenetic tree based on GA20 ox genes in Phyllostachys edulis showed that PeGA20 ox genes were mainly distributed in group A and group D,which revealed the functions of those genes might have some divergences.2.The expression patten of seven PeGA20 ox genes at different developmental stage of Phyllostachys edulis were analyzed by q RT-PCR.The results showed that PeGA20ox1 gene had a higher expression in the middle part of 7m shoot and also in the middle and lower part of 15 m shoot.We predicted that PeGA20ox1 gene may play an important role height growth of bamboo.Therefore,we selected PeGA20ox1 to clone and procced the further experiments.Subcellular localization showed that PeGA20ox1 protein was localized in both nucleus and cytoplasm.3.The promoter region of PeGA20ox1 gene was obtained by PCR,and its activity was analyzed by stable transformation to Arabidopsis thaliana.The results showed that PeGA20ox1 gene’s promoter region had activity and GUS gene was activated in leaves,stems,roots and hypocotyls of transgentic seedlings.4.Phenotypic complementation experiment showed that PeGA20ox1 gene could rescue the phenotype of mutant pg1.Phenotype of transgenic Arabidopsis thaliana showed that overexpression and specific expression of PeGA20ox1 gene both caused the increasement of plant height,biomass,lignin and cellulose content in transgenic Arabidopsis.5.T3 generation of transgenic rice about overexpression of PeGA20ox1 gene was obtained.Phenotype analysis showed overexpressed PeGA20ox1 gene in rice would also lead to the increasement of plant height,internode number and panicle in transgenic rice.