Initiation of aboveground organ primordia depends on combined action of auxin, ERECTA family genes, and PINOID
Initiation of aboveground organ primordia depends on combined action of auxin, ERECTA family genes, and PINOID
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DOI：
10.1093/plphys/kiac288
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发表时间：
2022-06-15
期刊：
影响因子：
7.4
通讯作者：
Shpak，Elena D.
中科院分区：
文献类型：
--
作者：
DeGennaro，Daniel;Camacho，Ricardo Andres Urquidi;Shpak，Elena D.
叶和花是由离中心一定距离的茎尖分生组织（SAM）产生的，这一过程需要生长素激素。生长素的数量及其在起始区的分布模式决定了器官原基的大小和空间排列。SAM中的生长素梯度是由PIN- formed （PIN）生长素外排载体形成的，其在质膜中的极性定位取决于蛋白激酶PINOID （PID）。先前的研究确定了erf家族基因控制叶片的起始。ERfs是一种质膜受体，通过感知来自表皮模式因子/EPF- like （EPF/EPFL）家族的细胞外小蛋白，实现细胞间的通信。在这里，我们研究了ERfs是否通过改变拟南芥（Arabidopsis thaliana）的生长素分布或信号传导来调节器官的起始。遗传和药理学数据表明ERfs不通过pin调节器官发生，而转录组学数据显示ERfs不改变对生长素的主要转录反应。我们的研究结果表明，在缺乏ERf信号的情况下，外周带细胞对生长素信号的响应不能有效地启动叶片，而生长素在erl1 erl2SAM中的积累增加可以部分地挽救器官启动缺陷。我们认为生长素和ERfs都是叶片形成所必需的，并且它们有共同的下游目标。遗传数据还表明，PID在子叶和叶片形成中的作用不能仅仅归因于PIN极性的调节，除了调节生长素分布外，PID可能还有其他功能。
Leaves and flowers are produced by the shoot apical meristem (SAM) at a certain distance from its center, a process that requires the hormone auxin. The amount of auxin and the pattern of its distribution in the initiation zone determine the size and spatial arrangement of organ primordia. Auxin gradients in the SAM are formed by PIN-FORMED (PIN) auxin efflux carriers whose polar localization in the plasma membrane depends on the protein kinase PINOID (PID). Previous work determined that ERECTA (ER) family genes (ERfs) control initiation of leaves. ERfs are plasma membrane receptors that enable cell-to-cell communication by sensing extracellular small proteins from the EPIDERMAL PATTERNING FACTOR/EPF-LIKE (EPF/EPFL) family. Here, we investigated whether ERfs regulate initiation of organs by altering auxin distribution or signaling in Arabidopsis (Arabidopsis thaliana). Genetic and pharmacological data suggested that ERfs do not regulate organogenesis through PINs while transcriptomics data showed that ERfs do not alter primary transcriptional responses to auxin. Our results indicated that in the absence of ERf signaling the peripheral zone cells inefficiently initiate leaves in response to auxin signals and that increased accumulation of auxin in theer erecta-like1(erl1)erl2SAM can partially rescue organ initiation defects. We propose that both auxin and ERfs are essential for leaf initiation and that they have common downstream targets. Genetic data also indicated that the role of PID in initiation of cotyledons and leaves cannot be attributed solely to regulation of PIN polarity and PID is likely to have other functions in addition to regulation of auxin distribution.