Histone Deacetylases and ASYMMETRIC LEAVES2 Are Involved in the Establishment of Polarity in Leaves of Arabidopsis[W]
Histone Deacetylases and ASYMMETRIC LEAVES2 Are Involved in the Establishment of Polarity in Leaves of Arabidopsis[W]
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DOI：
10.1105/tpc.106.042325
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发表时间：
2007-02
期刊：
影响因子：
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通讯作者：
Y. Ueno;T. Ishikawa;Keiro Watanabe;Shinji Terakura;H. Iwakawa;K. Okada;C. Machida;Y. Machida
中科院分区：
文献类型：
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作者：
Y. Ueno;T. Ishikawa;Keiro Watanabe;Shinji Terakura;H. Iwakawa;K. Okada;C. Machida;Y. Machida
我们发现，在突变体不对称LEAVES2(AS2)或AS1存在的情况下，组蛋白脱乙酰酶(HDAC)的两个拟南芥基因HDT1/HD2A和HDT2/HD2B是建立叶片极性所必需的。用HDACs抑制剂处理AS1或AS2植株后，叶片呈丝状，microRNA165和/或microRNA166(miR165/166)在叶片中分布异常。通过RNA干扰对这两个HDAC进行击倒突变，导致了与AS2背景中观察到的表型相似的表型。过量生产的AS2的核定位导致叶片中成熟miR165/166水平下降。这种异常被HDAC抑制剂消除，这表明AS2的作用需要HDAC。HASSTY中编码miRNA水平正向调节因子的功能丧失突变和PHABULOSA中编码adax化决定因素的功能获得突变，通过抑制AS1或AS2背景中的HDAC来抑制无轴丝状叶片的产生。AS2和AS1共存于邻近核仁的亚核小体中，同时发现HDT1/HD2A和HDT2/HD2B。我们的结果表明，这些HDAC和AS2和AS1独立地控制miR165/166的分布水平和/或模式以及叶片正面-背面极性的形成，在这些miRNAs的产生过程中，HDAC和AS2(AS1)之间可能存在相互作用。
We show that two Arabidopsis thaliana genes for histone deacetylases (HDACs), HDT1/HD2A and HDT2/HD2B, are required to establish leaf polarity in the presence of mutant ASYMMETRIC LEAVES2 (AS2) or AS1. Treatment of as1 or as2 plants with inhibitors of HDACs resulted in abaxialized filamentous leaves and aberrant distribution of microRNA165 and/or microRNA166 (miR165/166) in leaves. Knockdown mutations of these two HDACs by RNA interference resulted in phenotypes like those observed in the as2 background. Nuclear localization of overproduced AS2 resulted in decreased levels of mature miR165/166 in leaves. This abnormality was abolished by HDAC inhibitors, suggesting that HDACs are required for AS2 action. A loss-of-function mutation in HASTY, encoding a positive regulator of miRNA levels, and a gain-of-function mutation in PHABULOSA, encoding a determinant of adaxialization, suppressed the generation of abaxialized filamentous leaves by inhibition of HDACs in the as1 or as2 background. AS2 and AS1 were colocalized in subnuclear bodies adjacent to the nucleolus where HDT1/HD2A and HDT2/HD2B were also found. Our results suggest that these HDACs and both AS2 and AS1 act independently to control levels and/or patterns of miR165/166 distribution and the development of adaxial-abaxial leaf polarity and that there may be interactions between HDACs and AS2 (AS1) in the generation of those miRNAs.