Arabidopsis Pollen Fertility Requires the Transcription Factors CITF1 and SPL7 That Regulate Copper Delivery to Anthers and Jasmonic Acid Synthesis
Arabidopsis Pollen Fertility Requires the Transcription Factors CITF1 and SPL7 That Regulate Copper Delivery to Anthers and Jasmonic Acid Synthesis
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DOI：
10.1105/tpc.17.00363
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发表时间：
2017-12-01
期刊：
影响因子：
11.6
通讯作者：
Vatamaniuk, Olena K.
中科院分区：
文献类型：
--
作者：
Yan, Jiapei;Chia, Ju-Chen;Vatamaniuk, Olena K.
微量元素铜（Cu）的缺乏导致植物不育和籽粒/种子产量下降。铜如何影响生育力，哪些生殖结构需要铜，以及哪些转录网络协调铜向生殖器官的输送，目前尚不清楚。利用RNA-seq分析，研究人员发现，在铜缺乏的拟南芥花中，一个编码新型转录因子CITF1 （Cu- deficiency INDUCED transcription factor 1）的基因表达强烈上调。我们证明了CITF1调节铜的根吸收和向花的输送，是缺铜条件下植物正常生长所必需的。CITF1与铜稳态的主要调控因子SPL7 （SQUAMOSA启动子结合蛋白LIKE7）一起起作用，两者的功能是铜传递到花药和花粉繁殖所必需的。研究还发现，缺铜可上调花中茉莉酸（jasmonic acid， JA）生物合成基因的表达，增加叶片中内源茉莉酸的积累。这些效应部分由CITF1和SPL7控制。最后，我们发现JA可以调节CITF1的表达，并且缺乏CITF1和spl7调控基因LOX3和LOX4的JA生物合成突变体对铜缺乏敏感。总之，我们的数据表明，CITF1和SPL7调节铜的吸收和传递给花药，从而影响生育力，并强调了铜稳态、CITF1、SPL7和JA代谢途径之间的关系。
A deficiency of the micronutrient copper (Cu) leads to infertility and grain/seed yield reduction in plants. How Cu affects fertility, which reproductive structures require Cu, and which transcriptional networks coordinate Cu delivery to reproductive organs is poorly understood. Using RNA-seq analysis, we showed that the expression of a gene encoding a novel transcription factor, CITF1 (Cu-DEFICIENCY INDUCED TRANSCRIPTION FACTOR1), was strongly upregulated in Arabidopsis thaliana flowers subjected to Cu deficiency. We demonstrated that CITF1 regulates Cu uptake into roots and delivery to flowers and is required for normal plant growth under Cu deficiency. CITF1 acts together with a master regulator of copper homeostasis, SPL7 (SQUAMOSA PROMOTER BINDING PROTEIN LIKE7), and the function of both is required for Cu delivery to anthers and pollen fertility. We also found that Cu deficiency upregulates the expression of jasmonic acid (JA) biosynthetic genes in flowers and increases endogenous JA accumulation in leaves. These effects are controlled in part by CITF1 and SPL7. Finally, we show that JA regulates CITF1 expression and that the JA biosynthetic mutant lacking the CITF1-and SPL7-regulated genes, LOX3 and LOX4, is sensitive to Cu deficiency. Together, our data show that CITF1 and SPL7 regulate Cu uptake and delivery to anthers, thereby influencing fertility, and highlight the relationship between Cu homeostasis, CITF1, SPL7, and the JA metabolic pathway.