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基因枪介导的籼稻遗传转化及外源基因在受体中的遗传研究

GENE TRANSFORMATION BY PARTICLE BOM-BARDMENT IN INDICA RICE AND INHERITANCE OF THE FOREIGN GENE IN HOST RICE PLANT

  • 摘要: 由来自水稻成熟胚的愈伤组织或由此而建立的悬浮细胞系作基因枪转化的靶材料,将质粒pILTAB227(含hph基因和gus基因)导入籼稻,在Basmati-1、青油粘、新山粘29、胜优2号,明恢63等品种获得了转基因植株。T0转化体gus基因组织化学染色和DNA分子杂交(Southernblot)证实,gushph基因已整合到上述品种的基因组中。本实验仔细研究了hph基因在Basmati-1的T1、T2和T3等各个世代的遗传及表达。对T1家系中各个体核DNA的分子检测表明,hph基因普遍呈3:1的分离(转基因阳性:阴性),表明hph基因为单一位点的整合,其遗传符合单(显性)基因控制的孟德尔遗传规律。还发现一些株系表现1:1的不正常的分离(阳性个体较预期的少),推测这是由于雌或雄配子之一方的hph基因受到抑制而产生基因沉默的结果。在T2、T3世代获得了具hph基因的纯合体。笔者还探讨了外源基因在核基因组中的遗传稳定性及基因的沉默与活化问题

     

    Abstract: Embryogenic calli induced from mature seeds and cell suspensions were used as explants for particle bombardment.Plasmid p ILTAB2 2 7containing hph gene and gus gene under the control of Ca MV35 S was introduced into different varieties of Indica rice.Resistant plants of Indica rice varieties Basmati1,Qingyouzhan,Xinshanzhan2 9,Shengyou2,Minghui63were obtained.Tissue histochemical staining analysis of gus gene and Southern blot analysis of DNA isolated from leaves of T0 plants displayed the presence of gus and hph genes in the rice genome.We chose Basmati1as a model and evaluated the expression of hph gene in T1,T2 and T3generations in order to provide us to study further the expression,regulation and control of other important agronomically genes in rice.The segregation ratio of3:1(positive:negative for transgene) was found common in the T1progeny,itindicated that inheritance of transgene was in accordance with Mendelian rule of dominant gene with one locus.In addition, the selfed progeny of some independent plants show the segregation ratio of 1:1.Itwas assumed that the aberrant ratio of1:1resulted from gene suppression of female gamete or male gamete.Mendelian fashion of hph gene was further confirmed and homozygotes for hph gene were identified in the T2 and T3lines.Meanwhile,the suppression and activation of foreign gene in the progeny of transgenic plants was put forward to discussion.

     

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