SLOW MOTION is required for within-plant auxin homeostasis and normal timing of lateral organ initiation at the shoot meristem in Arabidopsis.
SLOW MOTION is required for within-plant auxin homeostasis and normal timing of lateral organ initiation at the shoot meristem in Arabidopsis.
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慢动作是拟南芥植物内生长素稳态和侧器官在芽分生组织启动的正常时间所必需的。
DOI：
10.1105/tpc.109.071498
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发表时间：
2010
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影响因子：
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通讯作者：
Lohmann D
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作者：
Lohmann D
植物茎周围的叶子和花的规则排列是生物模式形成的迷人表现。根据目前的模型，侧枝器官的间距是由极性生长素运输产生的短暂的本地生长素最大值，与现有的原基排水生长素从其附近，以限制附近的器官形成。目前还不清楚这种机制是否不仅编码空间信息，而且还编码关于质体时间的时间信息（即，连续原基形成之间的间隔）。在这里，我们确定了拟南芥F盒蛋白慢运动（SLOMO）作为一个正常的plastochron. SLOMO所需的极性生长素运输的组件进行遗传相互作用，突变的茎尖含有较少的自由生长素。然而，这种减少生长素水平在茎尖是不是由于增加极性生长素运输下来的茎，这表明它的结果从减少合成。植物中游离生长素水平的独立降低会导致与突变体中相似的质时线延长，这表明突变体茎尖中生长素水平的降低会延迟下一个生长素最大值的建立。SLOMO的作用不依赖于其他质时线调节剂，如ALTERED MERISTEM PROGRAM 1或KLUH/CYP 78 A5。我们认为SLOMO有助于茎分生组织中生长素的动态平衡，从而确保生长素最大值的形成和器官起始的正常速率。
The regular arrangement of leaves and flowers around a plant's stem is a fascinating expression of biological pattern formation. Based on current models, the spacing of lateral shoot organs is determined by transient local auxin maxima generated by polar auxin transport, with existing primordia draining auxin from their vicinity to restrict organ formation close by. It is unclear whether this mechanism encodes not only spatial information but also temporal information about the plastochron (i.e., the interval between the formation of successive primordia). Here, we identify theArabidopsis thalianaF-box protein SLOW MOTION (SLOMO) as being required for a normal plastochron.SLOMOinteracts genetically with components of polar auxin transport, and mutant shoot apices contain less free auxin. However, this reduced auxin level at the shoot apex is not due to increased polar auxin transport down the stem, suggesting that it results from reduced synthesis. Independently reducing the free auxin level in plants causes a similar lengthening of the plastochron as seen inslomomutants, suggesting that the reduced auxin level inslomomutant shoot apices delays the establishment of the next auxin maximum.SLOMOacts independently of other plastochron regulators, such asALTERED MERISTEM PROGRAM1orKLUH/CYP78A5. We propose thatSLOMOcontributes to auxin homeostasis in the shoot meristem, thus ensuring a normal rate of the formation of auxin maxima and organ initiation.