Stable inheritance of the antisense Waxy gene in transgenic rice with reduced amylose level and improved quality
Stable inheritance of the antisense Waxy gene in transgenic rice with reduced amylose level and improved quality
复制标题
反义Waxy基因在转基因水稻中稳定遗传，直链淀粉水平降低，品质提高
DOI：
10.1023/a:1022148824018
复制
发表时间：
2003-02-01
影响因子：
3
通讯作者：
Gu, MH
中科院分区：
文献类型：
--
作者：
Liu, QQ;Wang, ZY;Gu, MH
稻米胚乳直链淀粉含量是稻米食味和蒸煮品质的重要决定因素。在本研究中，嵌合反义构建体，其中包含一个756 bp的反义Wx基因的DNA片段从水稻和gusA编码序列，都融合到3.1 kb的水稻Wx启动子，有效地引入几个优良水稻品种，无论是粳稻和籼稻型，通过农杆菌。获得了200多个独立的转基因株系，并通过PCR和Southern杂交证实了转基因的整合。北方印迹分析表明，反义Wx转录本与内源Wx成熟mRNA和未剪接的转录本都相互作用，但仅与成熟mRNA相互作用导致直链淀粉合成减少。GUS活性分析表明，由水稻Wx启动子驱动的gusA融合基因在转基因水稻胚乳中高效表达。不同程度的减少直链淀粉含量，高达96%，被发现在种子来自这些转化体。在几个粳稻转基因株系中观察到一致的、不透明的白色种子，类似于糯米。在转基因籼稻品系中，通常具有高直链淀粉水平，胚乳中的直链淀粉含量也被发现显着减少，但减少的水平低于粳稻。遗传分析表明，转基因和提高的直链淀粉含量在这些转基因系中稳定遗传（直至第九代）。已经选择了几个具有改善的直链淀粉水平和品质的优良转基因品系用于田间评价。
Amylose content in rice endosperm is a key determinant of eating and cooking quality. In the present study, a chimeric antisense construct, which contained a 756-bp antisense Waxy (Wx) gene DNA fragment from rice and the gusA coding sequence, both fused to the 3.1-kb rice Wx promoter, was efficiently introduced into several elite rice cultivars, both of japonica and indica type, via Agrobacterium. More than 200 independent transgenic lines were produced and integration transgene was confirmed by PCR and Southern blotting. Northern blot analysis suggested that the antisense Wx transcript interacted with both the endogenous Wx mature mRNA and unspliced transcripts, but only interaction with the mature mRNA resulted in reduced amylose synthesis. Analysis of GUS activity showed that the gusA fusion gene driven by the rice Wx promoter expressed highly in the endosperm of the transgenic rice plants. Varying degrees of reduction in amylose content, up to 96%, were found in seeds derived from these transformants. Consistently, opaque white seeds, similar to glutinous rice, were observed in several transgenic lines of japonica rice. In transgenic lines derived from indica rice, which usually has a high amylose level, significant reduction of amylose content was also found in the endosperm, but the levels of reduction were lower than those of japonica rice. Genetic analysis demonstrated that transgenes and improved amylose content were stably inherited (up to ninth generation) in these transgenic lines. Several elite transgenic lines with improved amylose level and quality have been selected for field evaluation.