Transcriptome Profiling of Wheat Inflorescence Development from Spikelet Initiation to Floral Patterning Identified Stage-Specific Regulatory Genes
Transcriptome Profiling of Wheat Inflorescence Development from Spikelet Initiation to Floral Patterning Identified Stage-Specific Regulatory Genes
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DOI：
10.1104/pp.17.00310
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发表时间：
2017-07-01
期刊：
影响因子：
7.4
通讯作者：
Mao, Long
中科院分区：
文献类型：
--
作者：
Feng, Nan;Song, Gaoyuan;Mao, Long
谷物的早期生殖发育对最终穗粒数和作物的产量潜力至关重要。然而，到目前为止，还没有对普通小麦（Triticum aestivum）在这一重要过程中的基因表达谱进行系统分析。本研究研究了小麦从小穗萌发到花器官分化四个生殖发育阶段的转录组谱。K-means聚类和阶段特异性转录物鉴定检测了小穗和花分生组织中重要转录调控因子的动态表达同源物，这些调控因子可能涉及模式植物中的小穗起始、小花分生组织规范和花器官模式。小RNA转录组测序发现了小麦花序发育过程中与其靶基因差异表达的关键microrna，表明mirna介导的花发育调控机制可能在谷物和拟南芥中保守。ARGONAUTE1d （AGO1d）基因的功能特征进一步证实了我们的分析，该基因最初在雄蕊原基中表达，后来在花药成熟过程中在绒毡层中表达。在一个硬粒小麦四倍体突变体中，AGO1d的显性同源基因B的功能缺失导致花药比野生型更小，花粉不育性更强，每穗粒数减少，这与AGO1d的分期特异性表达模式一致。总之，我们的工作提供了小麦花序发育的基因调控网络的第一次一瞥，这可能是花和籽粒发育的关键，突出了遗传操作的潜在目标，以提高未来小麦产量。
Early reproductive development in cereals is crucial for final grain number per spike and hence the yield potential of the crop. To date, however, no systematic analyses of gene expression profiles during this important process have been conducted for common wheat (Triticum aestivum). Here, we studied the transcriptome profiles at four stages of early wheat reproductive development, from spikelet initiation to floral organ differentiation. K-means clustering and stage-specific transcript identification detected dynamically expressed homeologs of important transcription regulators in spikelet and floral meristems that may be involved in spikelet initiation, floret meristem specification, and floral organ patterning, as inferred from their homologs in model plants. Small RNA transcriptome sequencing discovered key microRNAs that were differentially expressed during wheat inflorescence development alongside their target genes, suggesting that miRNA-mediated regulatory mechanisms for floral development may be conserved in cereals and Arabidopsis. Our analysis was further substantiated by the functional characterization of the ARGONAUTE1d (AGO1d) gene, which was initially expressed in stamen primordia and later in the tapetum during anther maturation. In agreement with its stage-specific expression pattern, the loss of function of the predominantly expressed B homeolog of AGO1d in a tetraploid durum wheat mutant resulted in smaller anthers with more infertile pollens than the wild type and a reduced grain number per spike. Together, our work provides a first glimpse of the gene regulatory networks in wheat inflorescence development that may be pivotal for floral and grain development, highlighting potential targets for genetic manipulation to improve future wheat yields.