SLOW WALKER3, Encoding a Putative DEAD-box RNA Helicase, is Essential for Female Gametogenesis in Arabidopsis
SLOW WALKER3, Encoding a Putative DEAD-box RNA Helicase, is Essential for Female Gametogenesis in Arabidopsis
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SLOW WALKER3，编码一种假定的死盒 RNA 解旋酶，对于拟南芥雌性配子发生至关重要
DOI：
10.1111/j.1744-7909.2010.00972.x
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发表时间：
2010-09-01
影响因子：
11.4
通讯作者：
Yang, Wei-Cai
中科院分区：
文献类型：
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作者：
Liu, Man;Shi, Dong-Qiao;Yang, Wei-Cai
RNA解旋酶是腺苷三磷酸酶，其解旋RNA的二级结构，并且在RNA代谢的几乎任何方面都是必需的。从原核生物到真核生物，它们是高度保守的。然而，它们在植物生理和发育中的确切作用仍有待澄清。在这里，我们报告的突变基因慢步行者3（SWA 3）的结果在缓慢和延迟的有丝分裂过程中的巨配子发生在拟南芥。SWA 3是DEAD-box亚家族的一种推定的RNA解旋酶。突变体的发育停滞在4-或8-核期，约半数突变胚囊中的助细胞极性异常，细胞核位于合点端，而不是野生型的珠孔端。在swa 3中，通过雌配子体的突变传播严重减少。然而，一小部分突变胚囊能够发育成成熟的和功能的雌配子体时，授粉被推迟。拟南芥中的SWA 3是酵母中Dbp 8的同源物。Dbp 8与Efs 2相互作用，是酵母中18 S rRNA生物合成所必需的。我们的数据表明SWA 3可能与AtEfs 2形成复合物，并在拟南芥巨雌配子发生期间作为RNA解旋酶在核糖体生物合成中发挥作用。
RNA helicases are adenosine tri-phosphatases that unwind the secondary structures of RNAs and are required in almost any aspect of RNA metabolism. They are highly conserved from prokaryotic to eukaryotic organisms. However, their precise roles in plant physiology and development remain to be clarified. Here we report that the mutation in the gene SLOW WALKER3 (SWA3) results in the slow and retarded progression of mitosis during megagametogenesis in Arabidopsis. SWA3 is a putative RNA helicase of the DEAD-box subfamily. Mutant megagametophyte development is arrested at four- or eight-nucleate stages, furthermore, one of the synergids in about half of the mutant embryo sacs displays abnormal polarity, with its nucleus locating at the chalazal end, instead of the micropylar end in the wild-type. Transmission of the mutation through female gametophytes is severely reduced in swa3. However, a small portion of mutant embryo sacs are able to develop into mature and functional female gametophytes when pollination was postponed. The SWA3 in Arabidopsis is a homolog of Dbp8 in yeast. Dbp8 interacts with Efs2 and is essential for biogenesis of 18S rRNA in yeast. Our data suggest that SWA3 may form a complex with AtEfs2 and take roles in ribosomal biogenesis as RNA helicase during megagametogenesis in Arabidopsis.