【摘要】 很多研究表明,小麦胚乳淀粉的合成至少需要四类酶——腺苷二磷酸葡萄糖焦磷酸化酶、淀粉合成酶、淀粉分支酶和淀粉去分支酶,这四类酶的基因克隆和特性的研究有重要进展。目前,已从六倍体小麦发育胚乳的cDNA文库中获得AGPase两个亚基、gbss 、ss 、ss 、ss 、sbe 、sbe 和su1(dbe)等基因的cDNA;从六倍体小麦的D组供体Triticumtauschii基因组文库中获得ss 、ss 、ss 、sbe 和sbe 的gDNAs;从六倍体中只获得野生型和突变型的gbss (wx)基因。除编码AGPase大亚基的基因和su1基因未进行定位外,ss 位于第一群染色体上,sbe 位于2DL上,其余基因均位于第七群染色体上。更多还原

【Abstract】 Many researches aimed primarily at enzyme characterization show that there are at least four enzymes (including ADP-glucose pyrophosphorylase, starch synthase, starch branching enzyme and starch (debranching) enzyme) involved in starch biosynthesis of wheat endosperm. Genes coding for these enzymes have been cloned and identified. cDNA clones of AGPase, gbss Ⅰ, ss Ⅰ, ss Ⅱ, ss Ⅲ, sbe Ⅰ, sbe Ⅱ and su1 have so far been screened from cDNA libraries constructed from (developing) endosperm of hexaploid wheat (Triticum aestivum) . Genomic clones of ss Ⅰ, ss Ⅱ, ss Ⅲ, sbe Ⅰ, sbeⅡ have been isolated from genomic libraries of Triticum tauschii which is D genome donor of hexaploid wheat. And only wild and mutational genomic clones of gbss Ⅰ were (acquired) from hexaploid wheat. sbe Ⅱ have been mapped on 2DL, ss Ⅲ on Group 1 and others on Group 7 (chromosome) (excepted) that genes of AGPase large subunit and su1(dbe) have not been mapped.更多还原