Quantitative control of ASYMMETRIC LEAVES2 expression is critical for leaf axial patterning in Arabidopsis.
Quantitative control of ASYMMETRIC LEAVES2 expression is critical for leaf axial patterning in Arabidopsis.
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ASYMMETRIC LEAVES2 表达的定量控制对于拟南芥叶轴模式至关重要。
DOI：
10.1093/jxb/ert278
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发表时间：
2013-11
影响因子：
6.9
通讯作者：
Xu L
中科院分区：
文献类型：
--
作者：
Chen X;Wang H;Li J;Huang H;Xu L
ASYMMETRIC LEAVES 2（AS 2）是决定叶片近轴-远轴极性的关键基因之一。先前的数据表明，在叶发育中，AS 2直接被位于背轴的转录因子KANADI 1（KAN 1）抑制，因此AS 2转录本仅限于近轴叶结构域。这表明，与KAN 1的空间阻遏不同，AS 2在近轴域的定量阻遏对于确保正常的叶型形成也是至关重要的。通过分析两个功能获得型as 2突变体as 2 -5D和isoginchaku-2D（iso-2D），表明这些突变体相似的AS 2过表达表型反映了两种不同的AS 2错误表达模式。虽然as 2 -5D导致AS 2启动子处的KAN 1结合位点的破坏，导致AS 2在远轴侧的去阻遏，但不改变其叶的表达水平，iso-2D导致AS 2的过表达，但不改变其近轴表达模式。此外，发现在iso-2D中，与野生型和as 2 -5D中的组蛋白H3赖氨酸27三甲基化（H3 K27 me 3）和H3 K4 me 3的水平相比，在AS 2基因座处的组蛋白H3赖氨酸27三甲基化和H3 K4 me 3的水平分别显著降低和升高。这些结果表明，在叶图案，AS 2表达水平的定量控制可能涉及表观遗传调控。
ASYMMETRIC LEAVES2 (AS2) is one of the key genes required for specifying leaf adaxial identity during leaf adaxial–abaxial polarity establishment. Previous data have shown that, in leaf development, AS2 is directly repressed by an abaxially located transcription factor KANADI1 (KAN1), so that the AS2 transcripts are restricted only in the adaxial leaf domain. It is shown here that, different from the spatial repression by KAN1, the quantitative repression of AS2 in the adaxial domain is also critical for ensuring normal leaf pattern formation. By analysing two gain-of-function as2 mutants, as2-5D and isoginchaku-2D (iso-2D), it is shown that the similar AS2-over-expressed phenotypes of these mutants reflect two different kinds of AS2 misexpression patterns. While as2-5D causes disruption of a KAN1-binding site at the AS2 promoter leading to derepression of AS2 in the abaxial side but without changing its expression level of a leaf, iso-2D results in over-expression of AS2 but without altering its adaxial expression pattern. In addition, it was found that, in iso-2D, levels of histone H3 lysine 27 trimethylation (H3K27me3) and H3K4me3 at the AS2 locus are significantly reduced and increased, respectively, compared with those in the wild type and as2-5D. These results suggest that during leaf patterning, quantitative control of the AS2 expression level might involve epigenetic regulations.
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影响因子：
64.5
作者：
DREWS, GN;BOWMAN, JL;MEYEROWITZ, EM
通讯作者：
MEYEROWITZ, EM
影响因子：
9.2
作者：
Eshed, Y;Baum, SF;Bowman, JL
通讯作者：
Bowman, JL
影响因子：
64.8
作者：
Kerstetter, RA;Bollman, K;Poethig, RS
通讯作者：
Poethig, RS
影响因子：
11.4
作者：
Mallory, AC;Reinhart, BJ;Bartel, DP
通讯作者：
Bartel, DP
影响因子：
64.5
作者：
Eshed, Y;Baum, SF;Bowman, JL
通讯作者：
Bowman, JL