College of Life and Health Sciences, Northeastern University, Shenyang, Liaoning Province, China.
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning Province, China.
Plant Biol (Stuttg). 2019 Sep;21(5):882-890. doi: 10.1111/plb.12997. Epub 2019 May 15.
Biochar (BC) application could improve plant nitrogen (N) utilisation and potentially reduce N fertiliser requirements. However, the fate of N in crop-soil systems and the metabolic responses of crops under conditions of BC co-applied with reduced N are not well understood. The urea- N isotope and pot experiments with three BC rates (0%, 5% and 15%; w/w) combined with three N fertiliser levels (100% N, 85% N and 55% N) were conducted for maize. The metabolome, N abundance and gene expression in plants were analysed using nuclear magnetic resonance, gas isotope mass spectrometry and quantitative real-time reverse transcription PCR, respectively. The results showed that recovery of N by maize ranged from 27.4% to 23.6% and decreased as the N application rate decreased (from 100% to 55%) without BC addition, but ranged from 24.6% to 29.4% when BC was added at a rate of 5% and increased as the N application rate decreased. BC addition had major effects on global metabolic profiles and metabolic networks at the metabolomics level as well as on the expression of related genes (zmGS1and zmAS1) and the content of mineral N (NO , NO and NH ) in maize seedlings; moreover, the interaction effects of the BC application rates and N fertiliser levels were evident (P ≤ 0.001). BC addition induced a decrease in the flux toward sugar hydrolysis and maintained homeostasis in the amino acid pool, which was perturbed by reduced N levels; after which the maize plants adapted to the reduced N condition, and the N recovery efficiency ultimately improved with reduced N loss.
生物炭（BC）的应用可以提高植物氮（N）的利用率，并可能减少氮肥的需求。然而，作物-土壤系统中 N 的去向以及在与减少 N 共同施用 BC 的条件下作物的代谢反应尚不清楚。进行了三种生物炭施用量（0%、5%和 15%；w/w）与三种氮肥水平（100%N、85%N 和 55%N）相结合的玉米尿素-N 同位素和盆栽实验。利用核磁共振、气体同位素质量光谱和定量实时逆转录 PCR 分别分析了植物的代谢组、N 丰度和基因表达。结果表明，未添加 BC 时，玉米对 N 的回收率在 27.4%至 23.6%之间，随着施氮量的减少（从 100%减少到 55%）而降低，但添加 5%的 BC 时，回收率在 24.6%至 29.4%之间，随着施氮量的减少而增加。BC 添加在代谢组学水平上对全球代谢谱和代谢网络以及与相关基因（zmGS1 和 zmAS1）和玉米幼苗中矿质 N（NO 3 -、NO 2 -和 NH 4 +）含量的表达有重大影响；此外，BC 施用量和氮肥水平的相互作用效应明显（P≤0.001）。BC 添加诱导糖水解通量降低，并维持氨基酸池的内稳态，这受到低氮水平的干扰；之后，玉米植株适应了低氮条件，氮回收效率最终随着氮损失的减少而提高。
