NKD Transcription Factors Are Central Regulators of Maize Endosperm Development
NKD Transcription Factors Are Central Regulators of Maize Endosperm Development
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DOI：
10.1105/tpc.16.00609
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发表时间：
2016-12-01
期刊：
影响因子：
11.6
通讯作者：
Becraft, Philip W.
中科院分区：
文献类型：
--
作者：
Gontarek, Bryan C.;Neelakandan, Anjanasree K.;Becraft, Philip W.
裸胚乳1（NKD 1）和NKD 2是玉米胚乳发育中重要的重复插入区（IDD）转录因子。nkd 1和nkd 2突变体胚乳的RNA-seq分析显示，NKD 1和NKD 2影响发育中糊粉层中6.4%的转录组和淀粉胚乳中6.7%的转录组。NKD 1和NKD 2调控的过程包括基因表达、表观遗传功能、细胞生长和分裂、激素途径和资源储备沉积。NKD 1和NKD 2蛋白结合TTGTCGT的共有DNA序列，具有略微不同的性质。该基序在突变体胚乳中差异表达的基因转录本（DE）的启动子中富集。在59启动子区域中具有NKD结合基序的DE基因被认为是NKD 1和NKD 2调节的可能的直接靶基因，并且这些推定的直接靶基因明显富集了储存蛋白。转录实验表明，NKD 1和NKD 2可以直接调节基因转录，包括激活opaque 2和viviparous 1启动子。NKD 2作为nkd 1转录的负调节因子发挥作用，与先前报道的反馈调节一致。NKD 1和NKD 2可以通过其ID结构域同源和异源二聚化。这些分析表明NKD 1和NKD 2是发育中玉米胚乳基因表达的中心调节因子。
NAKED ENDOSPERM1 (NKD1) and NKD2 are duplicate INDETERMINATE DOMAIN (IDD) transcription factors important for maize (Zea mays) endosperm development. RNA-seq analysis of the nkd1 nkd2 mutant endosperm revealed that NKD1 and NKD2 influence 6.4% of the transcriptome in developing aleurone and 6.7% in starchy endosperm. Processes regulated by NKD1 and NKD2 include gene expression, epigenetic functions, cell growth and division, hormone pathways, and resource reserve deposition. The NKD1 and NKD2 proteins bind a consensus DNA sequence of TTGTCGT with slightly different properties. This motif was enriched in the promoters of gene transcripts differentially expressed (DE) in mutant endosperm. DE genes with a NKD binding motif in the 59 promoter region were considered as likely direct targets of NKD1 and NKD2 regulation, and these putative direct target genes were notably enriched for storage proteins. Transcription assays demonstrate that NKD1 and NKD2 can directly regulate gene transcription, including activation of opaque2 and viviparous1 promoters. NKD2 functions as a negative regulator of nkd1 transcription, consistent with previously reported feedback regulation. NKD1 and NKD2 can homo- and heterodimerize through their ID domains. These analyses implicate NKD1 and NKD2 as central regulators of gene expression in developing maize endosperm.