中文摘要：RNA干扰（RNAi）是一种广泛用于产生抗病毒转基因作物的方法。然而，一些农业重要问题，如RNAi介导的抗性在野外条件下长期的耐久性以及稳定的RNAi表达在植物中引起的潜在副作用等仍然很少有研究。本文开展了两种纯合转基因番茄品系（不同的选择性标记，表达出番茄黄化曲叶病毒CL基因同源内含子发夹结构RNA）田间试验和分子鉴定研究。研究结果揭示了转基因植物中siRNA介导的抗病毒沉默机制，并强调了该技术的适用局限性（可能会改变非靶标基因的转录模式）。
外文摘要：RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous trans genic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) Cl gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and down regulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes.
作者：Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; 等
作者单位：古巴遗传工程和生物技术中心
期刊名称：MOLECULAR PLANT-MICROBE INTERACTIONS
期刊影响因子：4.145
出版年份：2016
出版刊次：3
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