RNA interference (RNAi), one of the newly found ways for post-transcriptional gene si- lencing, has been widely used to investigate gene functions through transgenic methods for introducing an RNA silencing signal int...RNA interference (RNAi), one of the newly found ways for post-transcriptional gene si- lencing, has been widely used to investigate gene functions through transgenic methods for introducing an RNA silencing signal into plants. In the present study, we constructed a dexamethazone (DEX)-inducible RNAi binary vector harboring a specific sequence fragment (168-bp) homologous to KatB and KatC, two kinesin isoform genes of Arabidopsis, which were proved to result in the post-transcriptional gene si- lencing of KatB and KatC in DEX-induced transgenic plants. RT-PCR and Northern blot analysis on trans- genic homozygous Arabidopsis (termed as RNAi-type plants) showed that DEX inducement causes KatB and KatC mRNA degradation. With a simplified method, Arabidopsis grafting was effectively per- formed between RNAi-type and wild-type lines. The target gene mRNA levels were tested based on semi-quantitative RT-PCR. Our results demonstrateed that DEX-induced gene silencing signals could result in a reduction in KatB and KatC mRNA in the wild-type rootstocks or scions, indicating that silencing signals of RNAi could be transmitted bidirectionally across the graft junction whether RNAi-plants were scions or stocks. In contrast to the previously reported results on grafted tobacco, the transmission of post- tran- scriptional gene silencing signals caused by RNAi in grafted Arabidopsis is more effective than that in to- bacco.展开更多
基金This work was supported by grants from the National Natural Science Foundation of China （Grant Nos. 30170457, 30421002 ＆ 30370708）.
文摘RNA interference (RNAi), one of the newly found ways for post-transcriptional gene si- lencing, has been widely used to investigate gene functions through transgenic methods for introducing an RNA silencing signal into plants. In the present study, we constructed a dexamethazone (DEX)-inducible RNAi binary vector harboring a specific sequence fragment (168-bp) homologous to KatB and KatC, two kinesin isoform genes of Arabidopsis, which were proved to result in the post-transcriptional gene si- lencing of KatB and KatC in DEX-induced transgenic plants. RT-PCR and Northern blot analysis on trans- genic homozygous Arabidopsis (termed as RNAi-type plants) showed that DEX inducement causes KatB and KatC mRNA degradation. With a simplified method, Arabidopsis grafting was effectively per- formed between RNAi-type and wild-type lines. The target gene mRNA levels were tested based on semi-quantitative RT-PCR. Our results demonstrateed that DEX-induced gene silencing signals could result in a reduction in KatB and KatC mRNA in the wild-type rootstocks or scions, indicating that silencing signals of RNAi could be transmitted bidirectionally across the graft junction whether RNAi-plants were scions or stocks. In contrast to the previously reported results on grafted tobacco, the transmission of post- tran- scriptional gene silencing signals caused by RNAi in grafted Arabidopsis is more effective than that in to- bacco.
