Dpto. Biología de Plantas, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040-Madrid, Spain.
Mol Plant Pathol. 2004 Jul 1;5(4):361-6. doi: 10.1111/j.1364-3703.2004.00227.x.
SUMMARY Eukaryotic small RNA comprises several classes of 21-25 nucleotide non-coding RNA, of which microRNA (miRNA) has gained a great deal of attention because it is directly involved in controlling growth and development in plants. miRNAs are processed by the RNase III-like Dicer, although recent studies have implicated additional gene products in the step-wise maturation of miRNAs from their primary nuclear transcripts. They function as sequence-specific guides to trigger cleavage or translational repression of target mRNAs that have complementary sequences. Natural miRNA targets encode members of large families of transcription factors, which are collectively required for a number of developmental processes. In addition to developmental regulation, some miRNAs might be involved in specific physiological responses to several types of stresses, such as those induced by pathogen infections. Strikingly, the potyviruses, the largest group of plant RNA viruses, are able to interfere with miRNA-guided cleavage of multiple regulatory targets in plants, thus modulating gene expression of the host cell.
真核生物小分子 RNA 包括几类 21-25 个核苷酸的非编码 RNA，其中 microRNA（miRNA）受到了广泛关注，因为它直接参与了植物的生长和发育调控。miRNA 由 RNA 酶 III 样 Dicer 加工，尽管最近的研究表明，在 miRNA 从其初级核转录本逐步成熟的过程中，还有其他基因产物参与。它们作为序列特异性的向导，触发与互补序列的靶 mRNA 的切割或翻译抑制。天然 miRNA 的靶标编码转录因子大家族的成员，这些转录因子共同参与了许多发育过程。除了发育调控外，一些 miRNA 可能参与了对多种胁迫（如病原体感染诱导的胁迫）的特定生理反应。引人注目的是，植物 RNA 病毒中最大的一类——马铃薯 Y 病毒科，能够干扰 miRNA 指导的多个调控靶标在植物中的切割，从而调节宿主细胞的基因表达。
