State Key Laboratory of Crop Biology, Agronomy College, Shandong Agricultural University, Tai'an 271018, China.
Int J Mol Sci. 2018 Oct 31;19(11):3417. doi: 10.3390/ijms19113417.
Nitrogen fertilizer is a critical determinant of grain yield and seed quality in wheat. However, the mechanism of nitrogen level during seed production affecting wheat seed vigor and seedling establishment at the transcriptome level remains unknown. Here, we report that wheat seeds produced under different nitrogen levels (N0, N168, N240, and N300) showed significant differences in seed vigor and seedling establishment. In grain yield and seed vigor, N0 and N240 treatments showed the minimum and maximum, respectively. Subsequently, we used RNA-seq to analyze the transcriptomes of seeds and seedlings under N0 and N240 at the early stage of seedling establishment. Gene Ontology (GO) term enrichment analysis revealed that dioxygenase-activity-related genes were dramatically upregulated in faster growing seedlings. Among these genes, the top three involved linoleate 9S-lipoxygenase (, , and ). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that pathways involved in nutrient mobilization and the antioxidant system showed enhanced expression under N240. Moreover, seeds with faster growing seedlings had a higher gene expression level of α-amylase, which was consistent with α-amylase activity. Taken together, we propose a model for seedling establishment and seed vigor in response to nitrogen level during seed production.
氮肥是小麦籽粒产量和种子质量的关键决定因素。然而，在转录组水平上，种子生产过程中氮素水平如何影响小麦种子活力和幼苗建立的机制尚不清楚。在这里，我们报告说，在不同氮水平（N0、N168、N240 和 N300）下生产的小麦种子在种子活力和幼苗建立方面表现出显著差异。在籽粒产量和种子活力方面，N0 和 N240 处理的表现分别为最小和最大。随后，我们使用 RNA-seq 分析了幼苗建立早期 N0 和 N240 条件下种子和幼苗的转录组。基因本体论（GO）术语富集分析显示，与双加氧酶活性相关的基因在生长较快的幼苗中显著上调。在这些基因中，前三个涉及亚油酸 9S-脂氧合酶（、和）。京都基因与基因组百科全书（KEGG）富集分析显示，参与营养动员和抗氧化系统的途径在 N240 下表达增强。此外，生长较快的幼苗的种子具有更高的α-淀粉酶基因表达水平，这与α-淀粉酶活性一致。总之，我们提出了一个种子生产过程中氮水平对幼苗建立和种子活力响应的模型。
