Phenotypes Associated with Down-Regulation of Sl-IAA27 Support Functional Diversity Among Aux/IAA Family Members in Tomato
Phenotypes Associated with Down-Regulation of Sl-IAA27 Support Functional Diversity Among Aux/IAA Family Members in Tomato
复制标题
DOI：
10.1093/pcp/pcs101
复制
发表时间：
2012-09-01
影响因子：
4.9
通讯作者：
Audran-Delalande, Corinne
中科院分区：
文献类型：
--
作者：
Bassa, Carole;Mila, Isabelle;Audran-Delalande, Corinne
植物生长素是植物生长发育的重要调控因子，而Aux/IAA转录因子在植物生长素信号转导中起着关键作用。为了进一步了解Aux/IAA基因的多种功能，本研究描述了番茄Aux/IAA基因家族成员Sl-IAA 27的功能特性。与大多数Aux/IAA基因相比，S1-IAA 27在生长素对其表达的调控方面表现出独特的行为，并且S1-IAA 27编码的蛋白质具有也存在于S1-IAA 9中的未知功能的独特基序，并且在单子叶植物和双子叶植物物种中显著保守。低表达S1-IAA 27基因的番茄转基因植物揭示了与营养生长和生殖生长相关的多种表型。S1-IAA 27的沉默导致更高的生长素敏感性、改变的根发育和降低的叶片中的Chl含量。在Sl-IAA 27下调的品系中，胚珠和花粉都显示出育性的急剧丧失，并且花和果实的内部解剖结构被改变，在较小的果实中具有增大的胎座。与Sl-IAA 27 RNA干扰（RNAi）叶片中Chl含量降低一致，参与Chl合成的基因在转录物积累水平上显示较低的表达。尽管S1-IAA 27在序列同源性方面与S1-IAA 9密切相关，并且编码的蛋白质具有共同的结构特征，但数据表明这两个基因以不同的方式调节番茄果实的起始和发育。
The phytohormone auxin is known to regulate several aspects of plant development, and Aux/IAA transcription factors play a pivotal role in auxin signaling. To extend our understanding of the multiple functions of Aux/IAAs further, the present study describes the functional characterization of Sl-IAA27, a member of the tomato Aux/IAA gene family. Sl-IAA27 displays a distinct behavior compared with most Aux/IAA genes regarding the regulation of its expression by auxin, and the Sl-IAA27-encoded protein harbors a unique motif of unknown function also present in Sl-IAA9 and remarkably conserved in monocot and dicot species. Tomato transgenic plants underexpressing the Sl-IAA27 gene revealed multiple phenotypes related to vegetative and reproductive growth. Silencing of Sl-IAA27 results in higher auxin sensitivity, altered root development and reduced Chl content in leaves. Both ovule and pollen display a dramatic loss of fertility in Sl-IAA27 down-regulated lines, and the internal anatomy of the flower and the fruit are modified, with an enlarged placenta in smaller fruits. In line with the reduced Chl content in Sl-IAA27 RNA interference (RNAi) leaves, genes involved in Chl synthesis display lower expression at the level of transcript accumulation. Even though Sl-IAA27 is closely related to Sl-IAA9 in terms of sequence homology and the encoded proteins share common structural features, the data indicate that the two genes regulate tomato fruit initiation and development in a distinct manner.