Cytokinin-CLAVATA cross-talk is an ancient mechanism regulating shoot meristem homeostasis in land plants.
Cytokinin-CLAVATA cross-talk is an ancient mechanism regulating shoot meristem homeostasis in land plants.
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DOI：
10.1073/pnas.2116860119
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发表时间：
2022-04-05
影响因子：
11.1
通讯作者：
中科院分区：
文献类型：
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作者：
植物从它们的顶端生长。苔藓立碗藓的配子体（茎状器官）顶端是一个单细胞，其功能与多细胞开花植物相同，产生制造叶子的细胞并再生新的干细胞以维持茎尖。几种途径，包括CLAVATA和细胞分裂素激素信号，调节开花植物和苔藓中的干细胞丰度，尽管这些途径调节干细胞丰度的机制及其在这些植物谱系之间的保守性知之甚少。使用苔藓，我们研究了PpCLAVATA和细胞分裂素信号相互作用。总的来说，我们发现的证据表明，PpCLAVATA和细胞分裂素信号相互作用类似的苔藓和开花植物，尽管它们不同的解剖结构，生命周期和进化的距离。植物的芽是从茎顶端分生组织（SAM）中的干细胞生长出来的，SAM在维持干细胞库的同时产生侧生器官。在模式开花植物拟南芥中，CLAVATA（CLV）途径与细胞分裂素信号传导拮抗地起作用，以通过负调节干细胞组织者WUSCHEL（WUS）来控制多细胞SAM的大小。虽然只包含一个细胞，SAM的模式藓立碗藓（以前的立碗藓）执行相同的功能，在干细胞的维护和器官发生，尽管没有WUS介导的干细胞组织。我们以前的工作表明，受体CLAVATA 1（CLV 1）和受体样蛋白激酶2（RPK 2）的干细胞界定功能在藓类植物中是保守的。在这里，我们使用P. patens来评估CLV-细胞分裂素串扰是否也是干细胞调节的进化保守特征。细胞分裂素的应用产生类似于Ppclv 1a、Ppclv 1b和Pprpk 2突变体的异位干细胞表型。令人惊讶的是，细胞分裂素受体突变体在细胞分裂素信号传导不存在的情况下也形成异位干细胞。通过建模，我们确定了调控网络架构，概括了Ppclv 1a，Ppclv 1b和Pprpk 2突变体，细胞分裂素应用，细胞分裂素受体突变，以及这些扰动的高阶组合的干细胞表型。这些模型预测PpCLV 1和PpRPK 2通过不同的途径起作用，其中PpCLV 1抑制细胞分裂素介导的干细胞起始，PpRPK 2通过独立的细胞分裂素非依赖性途径抑制该过程。我们的分析表明，CLV 1和细胞分裂素信号之间的串扰是SAM稳态的一个进化上保守的功能，之前的作用WUS在干细胞组织。
Plants grow from their tips. The gametophore (shoot-like organ) tip of the moss Physcomitrium patens is a single cell that performs the same functions as those of multicellular flowering plants, producing the cells that make leaves and regenerating new stem cells to maintain the shoot tip. Several pathways, including CLAVATA and cytokinin hormonal signaling, regulate stem cell abundance in flowering plants and in mosses, although the mechanisms whereby these pathways regulate stem cell abundance and their conservation between these plant lineages is poorly understood. Using moss, we investigated how PpCLAVATA and cytokinin signaling interact. Overall, we found evidence that PpCLAVATA and cytokinin signaling interact similarly in moss and flowering plants, despite their distinct anatomies, life cycles, and evolutionary distance. Plant shoots grow from stem cells within shoot apical meristems (SAMs), which produce lateral organs while maintaining the stem cell pool. In the model flowering plant Arabidopsis, the CLAVATA (CLV) pathway functions antagonistically with cytokinin signaling to control the size of the multicellular SAM via negative regulation of the stem cell organizer WUSCHEL (WUS). Although comprising just a single cell, the SAM of the model moss Physcomitrium patens (formerly Physcomitrella patens) performs equivalent functions during stem cell maintenance and organogenesis, despite the absence of WUS-mediated stem cell organization. Our previous work showed that the stem cell–delimiting function of the receptors CLAVATA1 (CLV1) and RECEPTOR-LIKE PROTEIN KINASE2 (RPK2) is conserved in the moss P. patens. Here, we use P. patens to assess whether CLV–cytokinin cross-talk is also an evolutionarily conserved feature of stem cell regulation. Application of cytokinin produces ectopic stem cell phenotypes similar to Ppclv1a, Ppclv1b, and Pprpk2 mutants. Surprisingly, cytokinin receptor mutants also form ectopic stem cells in the absence of cytokinin signaling. Through modeling, we identified regulatory network architectures that recapitulated the stem cell phenotypes of Ppclv1a, Ppclv1b, and Pprpk2 mutants, cytokinin application, cytokinin receptor mutations, and higher-order combinations of these perturbations. These models predict that PpCLV1 and PpRPK2 act through separate pathways wherein PpCLV1 represses cytokinin-mediated stem cell initiation, and PpRPK2 inhibits this process via a separate, cytokinin-independent pathway. Our analysis suggests that cross-talk between CLV1 and cytokinin signaling is an evolutionarily conserved feature of SAM homeostasis that preceded the role of WUS in stem cell organization.
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影响因子：
1.6
作者：
Ishida, Kai;Yamashino, Takafumi;Mizuno, Takeshi
通讯作者：
Mizuno, Takeshi
影响因子：
56.9
作者：
Fletcher, LC;Brand, U;Meyerowitz, EM
通讯作者：
Meyerowitz, EM
影响因子：
11.6
作者：
Ikeda, Miho;Mitsuda, Nobutaka;Ohme-Takagi, Masaru
通讯作者：
Ohme-Takagi, Masaru
影响因子：
1.9
作者：
Barker, Elizabeth I.;Ashton, Neil W.
通讯作者：
Ashton, Neil W.
DOI：
10.1016/j.cub.2017.12.052
发表时间：
2018-02-05
期刊：
Current biology : CB
影响因子：
--
作者：
Moody LA;Kelly S;Rabbinowitsch E;Langdale JA
通讯作者：
Langdale JA