A comprehensive analysis of root morphological changes and nitrogen allocation in maize in response to low nitrogen stress
A comprehensive analysis of root morphological changes and nitrogen allocation in maize in response to low nitrogen stress
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DOI：
10.1111/pce.12439
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发表时间：
2015-04-01
影响因子：
7.3
通讯作者：
Mi, Guohua
中科院分区：
文献类型：
--
作者：
Gao, Kun;Chen, Fanjun;Mi, Guohua
根构型的可塑性对于植物适应包括低氮（LN）胁迫在内的不利环境至关重要。玉米根如何协调轴根和侧根（LRs）的生长，以及响应LN胁迫的纵向和径向细胞行为仍不清楚。在对照（4 mm硝酸盐）和LN（40 mm）条件下水培玉米植物。通过时间和空间取样，分析了轴根和LRs的形态、解剖结构和C/N比的变化。LN胁迫增加了侧根的伸长，减少了冠根的数量，降低了LR的密度和长度。LN胁迫延长了根中细胞的伸长区，增加了根中成熟细胞的长度。LN胁迫使冠根皮层中导管的直径和总面积减小，通气组织的数量增加，但细胞层数不变。C/N比值在轴根中高于LRs。玉米根系通过优化解剖结构和氮素分配来适应LN胁迫。结果表明，轴根伸长有利于有效地寻找土壤中的有效氮。
The plasticity of root architecture is crucial for plants to acclimate to unfavourable environments including low nitrogen (LN) stress. How maize roots coordinate the growth of axile roots and lateral roots (LRs), as well as longitudinal and radial cell behaviours in response to LN stress, remains unclear. Maize plants were cultivated hydroponically under control (4mm nitrate) and LN (40m) conditions. Temporal and spatial samples were taken to analyse changes in the morphology, anatomical structure and carbon/nitrogen (C/N) ratio in the axile root and LRs. LN stress increased axile root elongation, reduced the number of crown roots and decreased LR density and length. LN stress extended cell elongation zones and increased the mature cell length in the roots. LN stress reduced the cell diameter and total area of vessels and increased the amount of aerenchyma, but the number of cell layers in the crown root cortex was unchanged. The C/N ratio was higher in the axile roots than in the LRs. Maize roots acclimate to LN stress by optimizing the anatomical structure and N allocation. As a result, axile root elongation is favoured to efficiently find available N in the soil.