DICER-LIKE 4 functions in trans-acting small interfering RNA biogenesis and vegetative phase change in Arabidopsis thaliana
DICER-LIKE 4 functions in trans-acting small interfering RNA biogenesis and vegetative phase change in Arabidopsis thaliana
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DOI：
10.1073/pnas.0506426102
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发表时间：
2005-09-06
影响因子：
11.1
通讯作者：
Carrington, JC
中科院分区：
文献类型：
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作者：
Xie, ZX;Allen, E;Carrington, JC
拟南芥含有四个DICER-LIKE （DCL）基因，这些基因在RNA干扰相关的小RNA生物发生过程中具有专门的功能。我们发现了一个DCL4缺陷突变体，并分析了其microRNA和内源性小干扰RNA （siRNA）相关功能。dcl4-2突变体含有正常或接近正常水平的microrna （21 nt）和异染色质相关sirna （24 nt）。相比之下，该突变体缺乏三个家族的21-nt反式sirna (ta-siRNA)，并且ta-siRNA靶转录物水平升高。dcl4-2突变体类似于RNA依赖的RNA聚合酶6突变体，因为这两个突变体都缺乏ta- sirna，并表现出异慢性缺陷，从而加速了营养相变。dcl2-1、dcl3-1和DCL4 -2等位基因的双突变分析揭示了DCL活性之间的层次冗余，导致在没有DCL4的情况下ta-siRNA前体的替代加工。这些数据支持了植物对不同小RNA类别的生物发生具有专门和划分的DCL功能的概念。
Arabidopsis thaliana contains four DICER-LIKE (DCL) genes with specialized functions in small RNA biogenesis for RNA interference-related processes. A mutant with defects in DCL4 was identified and analyzed for microRNA- and endogenous, small interfering RNA (siRNA)-related functions. The dcl4-2 mutant contained normal or near-normal levels of microRNAs (21 nt) and heterochromatin-associated siRNAs (24 nt). In contrast, this mutant lacked each of three families of 21-nt trans-acting siRNAs (ta-siRNAs) and possessed elevated levels of ta-siRNA target transcripts. The dcl4-2 mutant resembled an rna-dependent RNA polymerase 6 mutant in that both mutants lacked ta-siRNAs and displayed heterochronic defects in which vegetative phase change was accelerated. Double mutant analyses with dcl2-1, dcl3-1, and dcl4-2 alleles revealed hierarchical redundancy among DCL activities, leading to alternative processing of ta-siRNA precursors in the absence of DCL4. These data support the concept that plants have specialized and compartmentalized DCL functions for biogenesis of distinct small RNA classes.