Arabidopsis thaliana myosin XIK is involved in root hair as well as trichome morphogenesis on stems and leaves
Arabidopsis thaliana myosin XIK is involved in root hair as well as trichome morphogenesis on stems and leaves
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DOI：
10.1007/s00709-006-0233-8
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发表时间：
2007-04-01
期刊：
影响因子：
2.9
通讯作者：
Truve, E.
中科院分区：
文献类型：
--
作者：
Ojangu, E.-L.;Jarve, K.;Truve, E.
肌球蛋白形成了一个大的超家族的分子马达，沿着沿着肌动蛋白丝运动。在植物细胞中，肌球蛋白的功能被认为与各种过程有关：细胞分裂、线粒体和叶绿体的运动、细胞质流动、跨液泡链的重排和平衡石定位。VIII类和XI类肌球蛋白在拟南芥基因组中分别由4个和13个潜在基因表示。XI类肌球蛋白及其细胞靶点在A.目前尚不清楚。在这项工作中，我们实施了一个反向遗传学的方法来分析XIK的功能丧失的突变体，在A. thaliana.三个不同的T-DNA插入突变体的肌球蛋白XIK基因表现出相似的表型：根毛细胞生长受损，茎毛扭曲的形状，和不规则的大小，分支定位，和分支扩展的叶毛。突变体幼苗的形态测量分析表明，根毛的平均长度减少了50%，与野生型根毛相比，这表明在尖端生长的XI类肌球蛋白XIK的参与。在叶片上，突变体植株中具有短枝的毛状体的比例增加了一倍，并且突变体毛状体具有轻度扭曲的形状。因此，我们得出结论，肌球蛋白XIK也参与了柄和分支的毛状体的伸长。
Myosins form a large superfamily of molecular motors that move along actin filaments. The functions of myosins in plant cells are thought to be related to various processes: cell division, movement of mitochondria and chloroplasts, cytoplasmic streaming, rearrangement of transvacuolar strands, and statolith positioning. Class VIII and XI myosins are represented in the Arabidopsis thaliana genome by 4 and 13 potential genes, respectively. The roles of individual class XI myosins and their cellular targets in A. thaliana are still unclear. In this work we implemented a reverse genetic approach to analyse the loss-of-function mutants of XIK, a representative of class XI myosins in A. thaliana. Three different T-DNA insertion mutants in the myosin XIK gene showed similar phenotypes: impaired growth of root hair cells, twisted shape of stem trichomes, and irregular size, branch positioning, and branch expansion of leaf trichomes. Morphometric analysis of mutant seedlings showed that the average length of root hairs was reduced up to 50% in comparison with wild-type root hairs, suggesting an involvement of the class XI myosin XIK in tip growth. On leaves, the proportion of trichomes with short branches was doubled in mutant plants, and the mutant trichomes possessed a mildly twisted shape. Therefore, we concluded that myosin XIK is involved also in the elongation of stalks and branches of trichomes.