【摘要】 籽粒硬度是小麦品质改良的重要目标性状。根据已报道的谷类作物中硬度主效基因 Pina和 Pinb的 DNA序列 ,设计了两对简并引物 ,以我国软质小麦品种京 4 11基因组 DNA为模板 ,进行 PCR扩增 ,分别获得了约 4 5 0 bp的Pina和 Pinb基因的全长特异性片段。将其克隆到 p GEM- 3Zf(+)上 ,重组子和酶切鉴定正确后 ,进行序列测定和分析。结果表明 ,与国外已克隆的软质小麦 Heron中 Pina基因相比较 ,京 4 11中 Pina与其核苷酸同源性为 98.9% ,氨基酸的同源性为 98% ,其全长为 4 4 7bp,编码 14 9个氨基酸残基 ,具有谷类作物中 Pina所特有 19个氨基酸的信号肽序列和 WWKWWK的色氨酸结构域。同样 ,与国外已克隆的软质小麦 Heron中 Pinb基因相比较 ,京 4 11中 Pinb与其核苷酸同源性为 99.8% ,氨基酸的同源性为 99.3% ,其全长为 4 4 7bp,编码 14 9个氨基酸残基 ,具有谷类作物中 Pinb所特有 19个氨基酸的信号肽序列和 KWWK的色氨酸结构域。硬度主效基因的分离克隆为进行我国小麦品种硬度的基因工程改良奠定了基础。更多还原

【Abstract】 Grain hardness is one of the most important characters in wheat quality improvement. Based on the homologues of Pin a and Pin b genes, which are major genes controlling the grain hardness in cereal crops, two pairs of degenerate primers were designed. The specific fragments of about 450 bp in size were obtained, respectively, after PCR amplification using the genomic DNA of wheat variety Jing411 as template. Then they were cloned into vector pGEM 3Zf(+), and sequenced after the identification of the recombinants and endonuclease analysis. The results indicated that, compared with the Pin a gene from wheat variety Heron, the Pin a gene in Jing411 shared 98.9% and 98% homology in nucleotide acid sequence and amino acid sequence, respectively. The whole length of Pin a gene was 447 bp, encoding 149 amino acid residues, having the signal peptide of 19aa and the tryptophan rich domain (WWKWWK) which are specific to Pin a gene in cereal crops. Similarly, the Pin b gene shared 99.8% and 99.3% homologies in nucleotide acid sequence and amino acid sequence respectively compared with the cloned Pin b gene in soft wheat variety Heron. The whole length of Pin b gene was 447 bp, encoding 149 amino acid residues, having the signal peptide of 19aa and the tryptophan rich domain (KWWK) which were specific to Pin b gene in cereal crops. The isolation of Pin a and Pin b gene laid a fundamental basis for further improvement of the grain hardness of wheat variety through genetic engineering.更多还原