Effect Of Growth Regulator On Growth Of Pear Dwarfing Mutants And Cloning Of Ga20-Oxidase Gene

With the purpose to illuminate the dwarf mechanism of the pear dwarfing mutant, we studied the effect of growth regulator treatment on growth of pear dwarfing mutant. The leaves of pear dwarfing mutant and Pingguoli were used as materials, two GA20-oxidase genes were isolated by reverse transcription polymerase chain reaction(RT-PCR) respectively. We had successfully constructed the plant overexpression vectors of PuGA20ox and PbGA20ox, which laid a foundation of studying the genetic transformation. The results are as follows:Pear dwarfing mutant is sensitive to the exogenous GA3、IAA、PP333,which is a GA-deficiency dwarf mutant.A GA20-oxidase gene was isolated from pear dwarfing mutant by RT-PCR technique. It’s full-length cDNA consists1179nucleotides and contains complete open reading frame (ORF) which encoding a protein of392amino acids residue, and named PuGA20ox. Homology analysis of the putative protein sequence showed that PuGA20ox shared respective homologies with PcGA20-ox、MdGA20-ox、FsGA20-ox、CiGA20-ox as98%、92%、81%、74%. The putative protein has all the conserved functional active sites and typical unit of the GA20-oxidase gene family.A GA20-oxidase gene was isolated from PingguoLi by RT-PCR technique. It’s full-length cDNA consists of1179nucleotides and contains complete open reading frame (ORF) which encoding a protein of392amino acids residue, and named PbGA20ox. Homology analysis of the putative protein sequence showed that PbGA20ox shared respective homologies with PcGA20-ox、MdGA20-ox、FsGA20-ox、CiGA20-ox as99%、92%、82%、75%. The putative protein has all the conserved functional active sites and typical unit of the GA20-oxidase gene family.The plant overexpression vectors of PuGA20ox and PbGA20ox which contains DNA fragment of GA20-oxidase gene were successfully constructed, and were introduced into Agrobacterium tumefaciens strains LBA4404, which laid a foundation of studying the genetic transformation and function of GA20-oxidase gene.