Abstract: Gibberellines are the most important phtyohormones influencing the plant height of fruit trees.Researches of the genes encoding the critical enzymes in gibberellin biosynthesis are significant to understanding the mechanism of dwarf tree architectures.This study reported the isolation of the MdCPS (GenBank accession number:KC433942.1),encoding CPS in apple, from primary apical shoots of the variety Fuji based on the apple genome database.The gDNA sequence of MdCPS contained 15 exons and 14 introns,and the coding sequence(CDS)of it was 2 400 bp,which encoded a polypeptide of 799 amino acids.The transcript MDP0000147908 that spanned chromosome 11 from location 32433834 to 32439214 in the published Golden delicious apple genome corresponds to this gene.Homology analysis indicated that the deduced MdCPS shared a higher level of similarity(49% -67%)with CPS protein from other plant species.Using the primary apical shoots of the parents and F₁ progenies of Fuji(standard)×Telamon(columnar)as plant materials,quantitative real-time PCR(qRT-PCR)analyses showed that even though the transcription level of this gene in the columnar parent was lower than that in the standard parent,there was no significant difference was observed between the two populations of columnar and standard progenies.At the same time,qRT-PCR analysis in the columnar hybrids and their correspondent standard mutants indicated that the expression level of MdCPS was not relevant to the columnar growth habit.These results suggested that the lower content of active gibberellins in columnar apple apical shoots was not distinctively influenced by MdCPS in the early stage of gibberellins synthesis.

Key words: Apple, Gibberellins, Ent-copalyl diphosphate synthase(CPS), Columnar trait

CLC Number: 

• Q78

• S661.03