SGS3 and SGS2/SDE1/RDR6 are required for juvenile development and the production of trans-acting siRNAs in Arabidopsis
SGS3 and SGS2/SDE1/RDR6 are required for juvenile development and the production of trans-acting siRNAs in Arabidopsis
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DOI：
10.1101/gad.1231804
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发表时间：
2004-10-01
影响因子：
10.5
通讯作者：
Poethig, RS
中科院分区：
文献类型：
--
作者：
Peragine, A;Yoshikawa, M;Poethig, RS
高等植物在开花之前经历从幼年到成年的营养发育阶段的过渡。筛选经历这一转变的突变体，早熟地产生转录后基因沉默（PTGS）所需的两个基因的等位基因-基因沉默3（SGS 3）和基因沉默2（SGS 2）/沉默缺陷1（SDE 1）IRNA依赖性聚合酶6（RDR 6）。这些基因中的功能丧失突变具有与Argonaute基因ZIPPY（ZIP）中的突变相似的表型。上位性分析表明ZIP、SGS 3、SGS 2/SDE 1/RDR 6和推定的miRNA输出受体HASTY（HST）在相同的途径中起作用。微阵列分析揭示了少量的基因，其mRNA在ZIP，SGS 3和SGS 2/SDE 1/RDR 6突变体中增加，以及在SGS 3和SGS 2/SDE 1/RDR 6突变体中上调的基因，但在ZIP突变体中不上调。后者的基因之一（At 5g 18040）是沉默转录后的反式sRNA 255家族的内源性，非编码，小干扰RNA（siRNA）。SGS 3和SGS 2/SDE 1/RDR 6突变体中At 5g 18040 mRNA的增加可归因于这些突变体中sRNA 255样siRNA的缺失。这些结果证明了内源性siRNA在基因表达调控中的作用，并表明PTGS在植物芽发育的时间控制中起着核心作用。
Higher plants undergo a transition from a juvenile to an adult phase of vegetative development prior to flowering. Screens for mutants that undergo this transition precociously produced alleles of two genes required for posttranscriptional gene silencing (PTGS)-SUPPRESSOR OF GENE SILENCING3 (SGS3) and SUPPRESSOR OF GENE SILENCING2(SGS2)/SILENCING DEFECTIVE1 (SDE1)IRNA-DEPENDENT POLYMERASE6 (RDR6). Loss-of-function mutations in these genes have a phenotype similar to that of mutations in the Argonaute gene ZIPPY (ZIP). Epistasis analysis suggests that ZIP, SGS3, SGS2/SDE1/RDR6, and the putative miRNA export receptor, HASTY (HST), operate in the same pathway(s). Microarray analysis revealed a small number of genes whose mRNA is increased in ZIP, SGS3, and SGS2/SDE1/RDR6 mutants, as well as genes that are up-regulated in SGS3 and SGS2/SDE1/RDR6 mutants, but not in ZIP mutants. One of these latter genes (At5g18040) is silenced posttranscriptionally in trans by the sRNA255 family of endogenous, noncoding, small interfering RNAs (siRNAs). The increase in At5g18040 mRNA in SGS3 and SGS2/SDE1/RDR6 mutants is attributable to the absence of sRNA255-like siRNAs in these mutants. These results demonstrate a role for endogenous siRNAs in the regulation of gene expression, and suggest that PTGS plays a central role in the temporal control of shoot development in plants.