To explore the molecular regulatory mechanism of high-carbon (C) sequestration Fraxinus mandshurica Rupr. (F. mandshurica) provenance and the expression profile of F. mandshurica during nitrogen (N) starvation, the foliage and roots of the annual Wuchang (WC) seedlings with greater C amount and Hailin (HL) seedlings with smaller C amount, which were grown in N-deficient nutrition and complete N, were used for RNA-seq and physiological determination, respectively. One thousand and fifty-seven differentially expressed genes (DEGs) between WC and HL and 8173 DEGs related to N deficiency were identified, respectively. The root of F. mandshurica responded to N deficiency more strongly than foliar. The target genes that responded to N deficiency in roots were mainly regulatory genes (transcription factors, hormones and protein kinases), and their response patterns were upregulated. The growth and N concentration in both WC and HL were reduced by the N deficiency, which might result from the decrease of the leaf Nitrate reductase (NR) and glutamine synthetase (GS) enzyme activity and ABA content, although the root-to-shoot ratio; lateral root number; lignin content; endogenous hormones content (GA, IAA and ZR); root GS and glutamate synthetase activity and transcriptional level of most of the regulatory genes were increased. The C sequestration capacity in WC was greater than that in HL, which related to the higher GS enzymes activity and transcriptional levels of regulatory genes and metabolic genes (terpenes, carbohydrates, and lipid energy). However, the C sequestration advantage of WC was significantly reduced by the N deficiency, which was due to the smaller response to N deficiency compared to HL.

中文翻译：

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水曲柳的转录组分析。氮素缺乏对不同固碳源幼苗的影响

探讨高碳（C）螯合水曲柳的分子调控机制。（F. mandshurica）种源和F. mandshurica在氮（N）饥饿，C量较大的一年生武昌（WC）幼苗和C量较小的Hailin（HL）幼苗的叶和根期间的表达谱生长在氮缺乏营养和完全氮的条件下，分别用于RNA序列测定和生理测定。分别确定了WC和HL之间的157个差异表达基因（DEG）和与N缺乏相关的8173个DEG。山茱F的根对氮缺乏的反应比对叶的反应更强烈。对根部氮素缺乏反应的靶基因主要是调控基因（转录因子，激素和蛋白激酶），其反应模式上调。氮缺乏导致WC和HL的生长和N浓度降低，这可能是由于叶片的硝酸根还原酶（NR）和谷氨酰胺合成酶（GS）酶活性和ABA含量降低，尽管从根部到茎部比率; 侧根数 木质素含量 内源激素含量（GA，IAA和ZR）；根部GS和谷氨酸合成酶的活性和大多数调控基因的转录水平均升高。WC中的C螯合能力大于HL中的C螯合能力，这与较高的GS酶活性以及调节基因和代谢基因（萜烯，碳水化合物和脂质能量）的转录水平有关。然而，由于缺氮，WC的固碳优势明显降低，这是由于与HL相比，对N缺乏的响应较小。