Excessive nitrogen application dampens antioxidant capacity and grain filling in wheat as revealed by metabolic and physiological analyses.
Excessive nitrogen application dampens antioxidant capacity and grain filling in wheat as revealed by metabolic and physiological analyses.
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DOI：
10.1038/srep43363
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发表时间：
2017-02-24
影响因子：
4.6
通讯作者：
Wang Z
中科院分区：
文献类型：
--
作者：
Kong L;Xie Y;Hu L;Si J;Wang Z
本研究以田间种植的小麦（小麦L.）正常（Nn）和过量（Ne）施肥处理。结果表明，Ne可抑制超氧化物歧化酶和过氧化物酶的活性，增加活性氧和丙二醛的积累。在开花期和乳熟期，Ne处理的归一化植被指数（NDVI）高于Nn处理，而在面团形成初期，Ne处理的归一化植被指数（NDVI）与Nn处理相近，而在硬面团形成期，Ne处理的归一化植被指数（NDVI）显著低于Nn处理。结果表明，Ne和Nn处理的小麦籽粒灌浆过程中存在99种不同的代谢产物，包括酚类和类黄酮化合物、氨基酸、有机酸和脂类等，主要参与活性氧的清除、氮代谢、热胁迫适应和抗病性。有机碳（C）和全氮含量的影响，与低C/N比后，中度牛奶。最终，谷物产量随着Ne的增加而下降。与正常施氮处理相比，过量施氮降低了小麦对活性氧的清除能力，增加了膜脂过氧化作用，引起了氮代谢、次生代谢和膜脂代谢的显著变化，从而导致小麦籽粒灌浆减少。
In this study, field-grown wheat (Triticum aestivum L.) was treated with normal (Nn) and excessive (Ne) levels of fertilizer N. Results showed that Ne depressed the activity of superoxide dismutase and peroxidase and increased the accumulation of reactive oxygen species (ROS) and malondialdehyde. The normalized difference vegetation index (NDVI) was higher under Ne at anthesis and medium milk but similar at the early dough stage and significantly lower at the hard dough stage than that under Nn. The metabolomics analysis of the leaf responses to Ne during grain filling showed 99 metabolites that were different between Ne and Nn treatments, including phenolic and flavonoid compounds, amino acids, organic acids and lipids, which are primarily involved in ROS scavenging, N metabolism, heat stress adaptation and disease resistance. Organic carbon (C) and total N contents were affected by the Ne treatment, with lower C/N ratios developing after medium milk. Ultimately, grain yields decreased with Ne. Based on these data, compared with the normal N fertilizer treatment, we concluded that excessive N application decreased the ability to scavenge ROS, increased lipid peroxidation and caused significant metabolic changes disturbing N metabolism, secondary metabolism and lipid metabolism, which led to reduced grain filling in wheat.