Bioinformatics And Function Analysis Of SOD Gene Family In Phyllostachys Edulis

The Phyllostachys edulis belongs to Bambusoideae of Graminaceae.As a bamboo species,it is economically important and produces profound ecological benefits in the Chinese society as well as around the world.With the continuous destruction of the natural environment and the dramatic global climate changes,the growing environment of Phyllostachys edulis started to deteriorate.These result in extensive damage to the bamboo forest and further lead to huge economic losses and in return accelerate the destruction of the local ecological environment.This study systematically characterized the SOD gene family bioinformatically along with the biological functions.The results are reported as below:1.The SOD protein sequences of model plants(Oryza sativa,Brachypodium distachyon and Arabidopsis thaliana)were downloaded from NCBI website.We identified seven protein sequences of SOD by aligned SOD protein sequences with the Phyllostachys edulis database,which including three Pe CZSOD,two Pe Mn SOD and two Pe Fe SOD proteins,meanwhile we found the corresponding SOD gene of SOD protein from Phyllostachys edulis transcription database.2.We conclude that the proteins of same subfamily share similar structure by sequence alignment.However,Phyllostachys edulis is geneticly closer to Oryza sativa,Brachypodium distachyon than Arabidopsis thaliana.3.Pe CZSOD subfamily protein are located in periplasm and chloroplast;all member of Pe Mn SOD subfamily have been found expressing in mitochondria,in contrast,the Pe Fe SOD subfamily proteins only exist in chloroplast of plant cell.4.Through the evolution slection pressure analysis,the Ka/Ks ratio of SOD genes far less than 1 in the evolutionary process of Phyllostachys edulis,which indicate there was strong purifying selection in the SOD genes.We suggest the SOD genes experienced a large-scale duplication event approximately 7-19 million years ago(MYA)and 180 MYA by analyzing Ks value.Meanwhile we suggest the divergence time for gene pair of Phyllostachys edulis with Bambusa oldhamii(Pe-Bo)and Phyllostachys edulis with Oryza sativa(Pe-Os)was approximately focus on 7-12 MYA and 9-82 MYA respectively.5.The promoter of SOD was extracted from genomic database and cis-element of SOD gene family member promoter was analyzed by the on-line tool of Plant Care.The result suggests abundant stress and hormone responsive element existing in the promoter region.Meanwhile their number and variety are significantly different.These results indicate that they possess different pathway respectively.6.The active analysis which promoter of SOD in P.Phyllostachys showed each region of promoter all had promoted activity and Pe CZSOD1-3 region(-497~-1bp)was stronger activity than other region.7.Three types of abiotic stress and three kinds of hormone treatment were used to treat the seedling of Phyllostachys edulis respectively.There seedlings were sampled in different periods.The SOD gene relative expressing of different time seedling sample under different abiotic and hormone treatment has been measured by Real-time PCR method.The same subfamily members has been clustered with closer distance,which showed the same subfamily genes has similar regulated trends of expressing.Meanwhile the SOD enzyme activity of same treatment sample has been measured.The results showed that the final SOD enzyme activity after ABA treated seedling was lower than untreated seedling.The other treatments of final SOD enzyme activity were higher than untreated.8.One gene from each subfamily SOD genes was cloned and and engineered into overexpression vector.Meanwhile the overexpression was used for translating Arabidopsis thaliana.The T2 transgenic lines have been transfered to ? MS solid medium with 300 m M Na Cl for study its resistance.The ultimate survival rate indicates the saltresistance of transgenic lines was significantly higher than wild line.