Expression and functional analysis of a CLV3-like gene in the model legume Lotus japonicus.
Expression and functional analysis of a CLV3-like gene in the model legume Lotus japonicus.
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DOI：
10.1093/pcp/pcr071
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发表时间：
2011-07
影响因子：
4.9
通讯作者：
S. Okamoto;T. Nakagawa;M. Kawaguchi
中科院分区：
文献类型：
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作者：
S. Okamoto;T. Nakagawa;M. Kawaguchi
植物地上部分由位于茎顶端分生组织（SAM）中的干细胞分化而来。CLAVATA 3（CLV 3）-CLV 1是一种众所周知的配体-受体对，其在SAM维持中起作用。在百脉根中，超结性畸变根形成1（HAR 1）与所有拟南芥受体样激酶（RLK）中的CLV 1具有最高的相似性。然而，HAR 1的功能在根瘤发育的系统调节，但似乎没有SAM维护的功能。因此，在L.大部分是未知的。在这里，我们确定了L。克隆了AtCLV 3的同源基因AtCLV 3-like（LjCLV 3），并进行了表达和功能分析。LjCLV 3转录本在茎分生组织的中心区域被检测到。然而，与AtCLV 3不同，LjCLV 3的表达在表皮层中未检测到，但在芽分生组织的内层中。LjCLV 3的RNA干扰（RNAi）不仅引起SAM的增大，而且引起初生和次生花序分生组织（IMs）的增大。此外，LjCLV 3沉默的植物表现出扁化茎和每个花序梗的花数增加。这些结果表明，LjCLV 3负责SAM以及初级和次级IM的维护。
Plant aerial parts are differentiated from stem cells that are located in the shoot apical meristem (SAM). CLAVATA3 (CLV3)-CLV1 is a well-known ligand-receptor pair, which functions in SAM maintenance. In Lotus japonicus, HYPERNODULATION ABERRANT ROOT FORMATION1 (HAR1) shows the highest similarity with CLV1 of all Arabidopsis receptor-like kinases (RLKs). However, HAR1 functions in the systemic regulation of root nodule development, but does not appear to function in SAM maintenance. Therefore, the gene that is responsible for SAM maintenance in L. japonicus is largely unknown. Here, we identified the L. japonicus CLV3-like (LjCLV3) gene as a counterpart of AtCLV3 and performed expression and functional analysis. LjCLV3 transcripts were detected in the central region of the shoot meristems. However, unlike AtCLV3, LjCLV3 expression was not detected in the epidermal layer, but in the inner layers of the shoot meristems. RNA interference (RNAi) of LjCLV3 caused enlargement of not only the SAM, but also the primary and secondary inflorescence meristems (IMs). Furthermore, LjCLV3-silenced plants exhibited fasciated stems and an increased number of flowers per peduncle. These results reveal that LjCLV3 is responsible for the maintenance of the SAM as well as the primary and secondary IMs.