【摘要】 细胞周期蛋白依赖性蛋白激酶基因CDKB，参与调控苹果(Malus×domestic Borkh.)果实大小的发育。为研究苹果果实大小的发育过程中CDKB的表达，以果实大小明显差异的‘国光’和‘富士’的果实为试材，从幼果果肉中克隆Md CDKB基因，并研究花后不同发育阶段的果实中Md CDKB基因的表达，主要结果如下：克隆得到921 bp的片段，分为两种序列，其ORF均为915 bp，编码304个氨基酸；其核苷酸和蛋白序列的最大一致性序列均为植物的CDKB基因，其最大一致性EST序列分别是‘嘎啦’苹果中的两个EST序列：CV085424(CDKB1;1)和EB138473(CDKB1;2)；生物信息学预测表明，其蛋白序列中有植物细胞周期依赖性蛋白激酶B1(CDKB1)的基序PPTALRE，属于植物CDKB家族的成员。因此，这两个序列命名为MdCDKB1;1和MdCDKB1;2。果实中MdCDB1;1和MdCDB1;2表达量的高峰分别在花后21d和7d，与幼果细胞快速分裂期一致，参与细胞分裂；在此过程中，MdCDB1;1的高表达水平和所保持的时间显著高于MdCDB1;2。大果型的‘富士’果实中，其MdCDKB1;1和MdCDB1;2的表达水平低于‘国光’，MdCDB1;1和MdCDKB1;2的表达水平，对‘国光’和‘富士’果实大小的差异无显著影响。更多还原

【Abstract】 Cyclin-dependent kinase B(CDKB) is one of cell cycle genes, and controls fruit cell number and fruit size in apple(Malus × domestic Borkh.). In order to explore Md CDKBexpression during the development of apple fruit,we used the cultivar ‘Ralls’ and ‘Fuji’ with the difference fruit size as materials, MdCDKB was cloned from pericarp and its expressing was studied during fruit growth stages. The segments were divided into two kinds of sequence, their open reading frames are 915 bp coding 304 amino acids. The maximum consistent sequences of nucleotide and protein were CDKB gene in plants,and the maximum consistent EST sequences are two EST sequences in ’Gala’ apple: CV085424(CDKB1;1)and EB138473(CDKB1;2).Bioinformatics predictions indicate that its protein sequence includes the motif PPTALRE of the plant cell cycle-dependent protein kinase B1(CDKB 1), belonging to plant CDKB subfamily. Therefore, the two sequences were named respectively Md CDKB1;1 and MdCDKB1;2. The expression peak of MdCDB1;1 and MdCDB1;2 occurred respectively at 21d and 7d after full bloom which coincided with rapid growth rate of early fruit, and would play roles during cell division; meanwhile the expressing level and the sustaining period of MdCDB1;1 is much higher and longer than MdCDB1;2. In ‘Fuji’ with larger fruit, the expression level of MdCDB1;1 and MdCDB1;2 are lower than in ‘Ralls’ with small fruit, the expressing level of MdCDB1;1 and MdCDB1;2 have no obvious effect on fruit size difference between ‘Ralls’ and ‘Fuji’.更多还原