OPAQUE11 Is a Central Hub of the Regulatory Network for Maize Endosperm Development and Nutrient Metabolism
OPAQUE11 Is a Central Hub of the Regulatory Network for Maize Endosperm Development and Nutrient Metabolism
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Opaque11 是玉米胚乳发育和营养代谢调控网络的中心枢纽
DOI：
10.1105/tpc.17.00616
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发表时间：
2018-02-01
期刊：
影响因子：
11.6
通讯作者：
Song, Rentao
中科院分区：
文献类型：
--
作者：
Feng, Fan;Qi, Weiwei;Song, Rentao
玉米(Zea Mays)胚乳是营养物质储存的主要组织，在发育过程中高度分化。然而，胚乳发育和营养代谢的调控网络在很大程度上仍然是未知的。玉米opaque11(O11)是一种典型的种子突变体，胚乳小而不透明，淀粉和蛋白质积累减少。我们克隆了O11，发现它编码一种胚乳特异的bHLH转录因子(Tf)。O11功能丧失显著影响了碳水化合物/氨基酸代谢和胁迫反应基因的转录。全基因组结合位点分析显示，9885个O11结合位点分布在6033个基因上。采用染色质免疫沉淀测序(CHIP-SEQ)和RNA测序(RNA-SEQ)相结合的方法，我们鉴定了259个O11调控的靶基因。在胚乳发育(NKD2和ZmDOF3)和营养代谢(O2和PBF)中，O11被发现直接调节关键的转录因子。此外，O11还直接调节cyPPDKs和多种碳水化合物代谢酶。O11是ZmYoda的激活子，提示其在胚乳发育过程中通过MAPK途径发挥调节作用。许多应激反应基因也是O11的直接靶标。此外，还鉴定了11个与O11相互作用的蛋白，包括协同调节应激反应靶标的ZmIce1和与O11相互作用的ZmYoda。因此，本研究揭示了一个以O11为中心的胚乳调控网络，它协调胚乳的发育、代谢和逆境反应。
Maize (Zea mays) endosperm is a primary tissue for nutrient storage and is highly differentiated during development. However, the regulatory networks of endosperm development and nutrient metabolism remain largely unknown. Maize opaque11 (o11) is a classic seed mutant with a small and opaque endosperm showing decreased starch and protein accumulation. We cloned O11 and found that it encodes an endosperm-specific bHLH transcription factor (TF). Loss of function of O11 significantly affected transcription of carbohydrate/amino acid metabolism and stress response genes. Genome-wide binding site analysis revealed 9885 O11 binding sites distributed over 6033 genes. Using chromatin immunoprecipitation sequencing (ChIP-seq) coupled with RNA sequencing (RNA-seq) assays, we identified 259 O11-modulated target genes. O11 was found to directly regulate key TFs in endosperm development (NKD2 and ZmDOF3) and nutrient metabolism (O2 and PBF). Moreover, O11 directly regulates cyPPDKs and multiple carbohydrate metabolic enzymes. O11 is an activator of ZmYoda, suggesting its regulatory function through the MAPK pathway in endosperm development. Many stress-response genes are also direct targets of O11. In addition, 11 O11-interacting proteins were identified, including ZmIce1, which coregulates stress response targets and ZmYoda with O11. Therefore, this study reveals an endosperm regulatory network centered around O11, which coordinates endosperm development, metabolism and stress responses.