When the BRANCHED network bears fruit: how carpic dominance causes fruit dimorphism in Aethionema
When the BRANCHED network bears fruit: how carpic dominance causes fruit dimorphism in Aethionema
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DOI：
10.1111/tpj.13861
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发表时间：
2018-04-01
期刊：
影响因子：
7.2
通讯作者：
Theissen, Guenter
中科院分区：
文献类型：
--
作者：
Lenser, Teresa;Tarkowska, Danuse;Theissen, Guenter
生活在不可预测的栖息地变化中是一个巨大的挑战，特别是对于植物这样的固着生物。果实和种子的异型性是科普这种多变的环境条件的一种方法。它指的是不同类型的果实和种子的生产，这些果实和种子往往在传播、萌发和幼苗建立方面介导不同的生活史策略。但是，尽管这种现象可以在许多物种中发现，并且显然独立地进化了几次，但其发育时间过程或分子调控在很大程度上仍然未知。在这里，我们研究了果实发育Aethionema arabicum，一个二型的成员，拟南芥科。通过比较分析果实生长、种子败育和开裂带发育等鉴别性状，对果实形态分化进行了表征。我们的数据表明，果实形态的确定是最后一分钟的决定发生在花后的花，直接在第一个形态差异开始发生之前。结合激素和基因表达分析的几个生长实验进一步表明，植物激素生长素和细胞分裂素在开放的花朵中的积累平衡以及Ae的转录丰度。BRANCHED 1的阿拉伯树胶直系同源物，编码一种转录因子，已知其作为分支抑制子的保守功能，可以指导果实形态的确定。因此，我们假设，在Ae的果实形态比的可塑性。虽然生产两种不同类型的水果是经常发现在植物中茁壮成长，在不可预测的变化栖息地，没有工作已经报道，但检查发育的时间过程或水果二型性的分子基础。在这里，我们发现的发育时间点的水果形态决定在二态Aethionema阿拉伯和识别分子候选人，可能机械地连接水果类型的决定，发展计划管理carpic优势。
Life in unpredictably changing habitats is a great challenge, especially for sessile organisms like plants. Fruit and seed heteromorphism is one way to cope with such variable environmental conditions. It denotes the production of distinct types of fruits and seeds that often mediate distinct life-history strategies in terms of dispersal, germination and seedling establishment. But although the phenomenon can be found in numerous species and apparently evolved several times independently, its developmental time course or molecular regulation remains largely unknown. Here, we studied fruit development in Aethionema arabicum, a dimorphic member of the Brassicaceae family. We characterized fruit morph differentiation by comparatively analyzing discriminating characters like fruit growth, seed abortion and dehiscence zone development. Our data demonstrate that fruit morph determination is a last-minute' decision happening in flowers after anthesis directly before the first morphotypical differences start to occur. Several growth experiments in combination with hormone and gene expression analyses further indicate that an accumulation balance of the plant hormones auxin and cytokinin in open flowers together with the transcript abundance of the Ae. arabicum ortholog of BRANCHED1, encoding a transcription factor known for its conserved function as a branching repressor, may guide fruit morph determination. Thus, we hypothesize that the plasticity of the fruit morph ratio in Ae. arabicum may have evolved through the modification of a preexisting network known to govern correlative dominance between shoot organs.Significance Statement Although the production of two distinct types of fruits is often found in plants that thrive in unpredictably changing habitats, no work has been reported yet examining the developmental time course or molecular basis of fruit dimorphism. Here, we discover the developmental time point of fruit morph determination in dimorphic Aethionema arabicum and identify molecular candidates that may mechanistically link fruit type determination to the developmental program governing carpic dominance.