Institute of Soil Fertilizer and Resources Environment, Jiangxi Academy of Agricultural Sciences, Nanchang, China.
PLoS One. 2020 Jul 10;15(7):e0235975. doi: 10.1371/journal.pone.0235975. eCollection 2020.
Rice cultivar "Weiyou916" (Oryza sativa L. ssp. Indica) were cultured with control (10 mM NO3-) and nitrate deficient solution (0 mM NO3-) for four weeks. Nitrogen (N) deficiency significantly decreased the content of N and P, dry weight (DW) of the shoots and roots, but increased the ratio of root to shoot in O. sativa. N deficiency decreased the photosynthesis rate and the maximum quantum yield of primary photochemistry (Fv/Fm), however, increased the intercellular CO2 concentration and primary fluorescence (Fo). N deficiency significantly increased the production of H2O2 and membrane lipid peroxidation revealed as increased MDA content in O. sativa leaves. N deficiency significantly increased the contents of starch, sucrose, fructose, and malate, but did not change that of glucose and total soluble protein in O. sativa leaves. The accumulated carbohydrates and H2O2 might further accelerate biosynthesis of lignin in O. sativa leaves under N limitation. A total of 1635 genes showed differential expression in response to N deficiency revealed by Illumina sequencing. Gene Ontology (GO) analysis showed that 195 DEGs were found to highly enrich in nine GO terms. Most of DEGs involved in photosynthesis, biosynthesis of ethylene and gibberellins were downregulated, whereas most of DEGs involved in cellular transport, lignin biosynthesis and flavonoid metabolism were upregulated by N deficiency in O. sativa leaves. Results of real-time quantitative PCR (RT-qPCR) further verified the RNA-Seq data. For the first time, DEGs involved oxygen-evolving complex, phosphorus response and lignin biosynthesis were identified in rice leaves. Our RNA-Seq data provided a global view of transcriptomic profile of principal processes implicated in the adaptation of N deficiency in O. sativa and shed light on the candidate direction in rice breeding for green and sustainable agriculture.
水稻品种“威优 916”（Oryza sativa L. ssp. Indica）在对照（10 mM NO3-）和缺硝酸盐溶液（0 mM NO3-）中培养了四周。氮素缺乏显著降低了 shoot 和 root 的氮、磷含量和干重，但增加了 O. sativa 的根冠比。氮素缺乏降低了光合作用速率和初级光化学的最大量子产量（Fv/Fm），但增加了胞间 CO2 浓度和初级荧光（Fo）。氮素缺乏显著增加了 H2O2 的产生和膜脂过氧化，表现为 O. sativa 叶片 MDA 含量的增加。氮素缺乏显著增加了淀粉、蔗糖、果糖和苹果酸的含量，但没有改变葡萄糖和总可溶性蛋白的含量。在氮限制下，积累的碳水化合物和 H2O2 可能进一步加速 O. sativa 叶片中木质素的生物合成。Illumina 测序显示，1635 个基因对氮缺乏表现出差异表达。GO 分析表明，195 个 DEGs 高度富集在 9 个 GO 术语中。大多数与光合作用、乙烯和赤霉素生物合成相关的 DEGs 下调，而大多数与细胞运输、木质素生物合成和类黄酮代谢相关的 DEGs 上调。实时定量 PCR（RT-qPCR）的结果进一步验证了 RNA-Seq 数据。首次在水稻叶片中鉴定到与放氧复合体、磷响应和木质素生物合成相关的 DEGs。我们的 RNA-Seq 数据提供了一个 O. sativa 适应氮缺乏的主要过程的转录组谱的全局视图，并为水稻绿色和可持续农业的育种提供了候选方向。
