比较和分析NtGNL1的反义寡聚核苷酸抑制在烟草三种培养体系中的效果

Comparison and Analysis of Effects of Antisense Oligodeoxynucleotide Inhibition of NtGNL1 in Three Culture Systems of Tobacco

为探讨反义寡聚核苷酸抑制(antisense oligodeoxynucleotides inhibition)技术在植物材料上的应用,以已知功能的NtGNL1(Nicotiana tabacum GNOM-Like1)为目标基因,寻找反义寡聚核苷酸抑制最适作用体系,并进一步分析NtGNL1的具体作用。根据目标基因mRNA序列设计反义寡聚核苷酸序列,商业合成后并将其添加到烟草胚珠、种子和花粉管离体培养的培养基中,以抑制NtGNL1的表达。结果表明,将反义寡聚核苷酸引入离体培养系统,短时间内抑制了目标基因mRNA的表达,但对胚胎发育过程的影响和种子萌发的抑制都不明显。在花粉离体萌发系统中,反义寡聚核苷酸抑制能够高效地引起目标基因mRNA的下调。对FM4-64染色的花粉管显微缩时观察发现,NtGNL1的下调能够引起囊泡分布和运输方向的改变。对花粉管膜流相关的5个基因的半定量分析也显示反义寡聚核苷酸进入花粉管后,导致3个基因的表达下调,暗示NtGNL1抑制表达会影响花粉管囊泡运输的多个节点。

To develop the antisense oligonucleotide inhibition technology in plant materials, we used the known-function-gene NtGNL1 as the target to establish the optimum application system and further analyze the specific role of NtGNL1. Based on the mRNA of target gene, we designed, commercially synthesized and then applied the antisense oligonucleotide sequences into the in vitro cultured ovules, seeds and pollen tubes to inhibit the expression of NtGNL1. The results revealed that the co-culture of an- tisense oligodeoxynucleotides hardly affected the pattern formation of the embryos, as well as the seeds germination, despite the expression of NtGNL1 decreasing during short periods. Significantly, the antisense oligodeoxynucleotides down-regulated the expression of target gene in the in vitro cultured pollen tubes. Microscopic time laps observation of pollen tubes by FM4-64 stain- ing indicated that the inhibition also changed the vesicles distribution model and the direction of vesicle trafficking. Furthermore, the mRNA expression of five genes related to membrane trafficking was also analyzed by semi-quantitative PCR, showing that three genes were down-regulated after the antisense oligodeoxynucleotides entered into the pollen tubes. All these results implied that the inhibition of NtGNL1 expression will affect several key points of vesicle trafficking in pollen tubes.