中文摘要：

【目的】研究半矮生型桃‘SD9238’F-box基因的序列特征及F-box基因在新梢生长跃变期的表达与节间伸长的关系,为进一步研究该基因调控半矮生型桃植株生长的分子机制奠定基础。【方法】利用基因克隆和RACE技术获得‘SD9238’F-box基因的gDNA及cDNA序列,并分析该基因的序列特征。采用qRT-PCR分析该基因在新梢生长跃变期的表达水平。【结果】获得F-box基因gDNA全长3 650 bp,cDNA全长1 936 bp,GeneBank登陆号为KF023192。该基因ORF长1 509 bp编码502个氨基酸,蛋白质分子质量55.984 kD。生物信息学分析表明,氨基酸序列具有F-box蛋白家族中LRR的结构特征,与蔷薇科中苹果和草莓的F-box基因同源,相似性达98%。QRT-PCR分析结果表明,F-box基因在节间生长跃变期表达量的动态变化与新梢节间的伸长速率动态变化趋势一致,其基因相对表达量在半矮生型桃中于节间生长跃变点5月22日达到最大值,为第一时期的9.4倍;在普通型桃中同样于5月22日达到基因相对表达量的最大值,但只为第一时期的2.2倍。【结论】获得了‘SD9238’新梢中F-box基因KF023192的序列全长,并明确了该基因的序列特征。对该基因在新梢生长过程的动态表达分析显示,KF023192可能参与了半矮生桃新梢节间生长的调控。

英文摘要：

[Objective]In order to clarify the sequence characteristics and its relationship between expres- sion level and shoot internode elongation of F-box gene in semi-dwarf peach ＇SD9238＇, then lay founda- tion for further study on the regulation mechanism of F-box in semi-dwarf plants, [Method]the gDNA and cDNA sequence of F-box gene was obtained by cloning and RACE in this study. The expression level of F-box gene during the jump-change stage was researched by qRT-PCR. [Result]The sequence analysis showed that the gDNA sequence was 3650 bp, and the cDNA sequence was 1 936 bp, which contained an ORF of 1 509 bp encoding 502aa with 55.984 kD molecular mass. Its GeneBank accession number is KF023192. Bioinformatics analysis revealed that the protein was characterized by LRR and homology with apple and strawberry of Rosaceae plants with 99 support value. QRT-PCR results showed that the expres- sion level of F-box was consistent with the shoot internode growth, which obtained its maximum in May 22nd and it was about 9 times of the first stage in ＇SD9238＇ as well as twice in normal. [Conclusion]The full length of KF023192 was cloned and its sequence characteristics was illustrated. In addition, the study indicated that KF023192 was active in regulating the internode growth of ＇SD9238 .