CsAP3: A Cucumber Homolog to Arabidopsis APETALA3 with Novel Characteristics.
CsAP3: A Cucumber Homolog to Arabidopsis APETALA3 with Novel Characteristics.
复制标题
DOI：
10.3389/fpls.2016.01181
复制
发表时间：
2016
影响因子：
5.6
通讯作者：
Bai SN
中科院分区：
文献类型：
--
作者：
Sun JJ;Li F;Wang DH;Liu XF;Li X;Liu N;Gu HT;Zou C;Luo JC;He CX;Huang SW;Zhang XL;Xu ZH;Bai SN
在我们之前了解黄瓜单性花发育调控机制的过程中，我们观察到在黄瓜雌花发育的第6阶段，乙烯受体CsETR1的雄蕊特异性下调。这种下调与原始花药特有的DNA损伤有关，这种损伤是黄瓜雌花雄蕊发育不正常的特征。为了了解CsETR1是如何在雄蕊中下调的，我们鉴定了一个与拟南芥AP3，CsAP3同源的黄瓜MADS盒基因。我们证明了CsAP3在功能上等同于拟南芥B类MADS基因AP3。然而，发现了CsAP3的三个新特征。这包括：第一，在体内和体外结合和激活CsETR1启动子；第二，在其C端含有一个GV重复序列，该重复序列在葫芦中保守，是转录激活所必需的；第三，随着节数的增加，表达减少，这与CsETR1的发现类似。这些发现不仅揭示了CsAP3作为B类花特性基因的保守功能，而且揭示了其在黄瓜雌花发育调控中的独特功能。
In our previous efforts to understand the regulatory mechanisms of cucumber unisexual flower development, we observed a stamen-specific down-regulation of the ethylene receptor CsETR1 in stage 6 female flowers of cucumber (Cucumis sativus L.). This down-regulation is correlated with the primordial anther-specific DNA damage that characterizes inappropriate stamen development in cucumber female flowers. To understand how CsETR1 is down regulated in the stamen, we characterized a cucumber MADS box gene homologous to Arabidopsis AP3, CsAP3. We demonstrated that CsAP3 is functionally equivalent to the Arabidopsis B-class MADS gene AP3. However, three novel characteristics of CsAP3 were found. These include firstly, binding and activating CsETR1 promoter in vitro and in vivo; secondly, containing a GV repeat in its C-terminus, which is conserved in cucurbits and required for the transcription activation; and thirdly, decreased expression as the node number increases, which is similar to that found for CsETR1. These findings revealed not only the conserved function of CsAP3 as a B-class floral identity gene, but also its unique functions in regulation of female flower development in cucumber.