ZD958 is a low-nitrogen-efficient maize hybrid at the seedling stage among five maize and two teosinte lines
ZD958 is a low-nitrogen-efficient maize hybrid at the seedling stage among five maize and two teosinte lines
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ZD958是5个玉米和2个大蜀黍品系苗期低氮效率玉米杂交种
DOI：
10.1007/s00425-015-2331-3
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发表时间：
2015-10-01
期刊：
影响因子：
4.3
通讯作者：
Li, Xuexian
中科院分区：
文献类型：
--
作者：
Han, Jienan;Wang, Lifeng;Li, Xuexian
主要结论ZD 958是5个玉米和2个大刍草中氮效率最低的品系，小颖玉米和双颖玉米对氮限制不敏感。玉米和大刍草在基因调控上存在遗传和进化上的分歧。GDH 2、ASN 2和T4在7个细胞系中持续下调。母本不对称遗传和杂种优势使ZD 958氮效率低下，氮素缺乏仍是许多发展中国家玉米生产的严重限制因素。更好地了解杂交玉米如何应对氮限制尤其重要。本研究以我国北方玉米高产优势杂交种ZD 958为材料，在生理和转录水平上与其它4个玉米品系和2个大刍草品系进行了比较分析。在5个玉米和2个大刍草品系中，ZD 958在氮限制条件下以最低氮浓度积累最多，是氮效率最低的品系;而小颖玉米和双颖玉米根系较大，对氮限制不敏感。与ZD 958根系中N代谢基因的下调反向平行，碳向根系的分配增加，根长显著增加。10个调节氮素吸收、运输和代谢的基因表达模式的变化表明，在氮素限制下，7个品系之间存在较大的遗传和进化差异。值得注意的是，GDH 2，ASN 2，和VAAT 5一致下调下，这些玉米和大刍草线，表明必要的进化保守的基因调控响应氮限制和氮营养诊断提供分子标记。ZD 958的遗传不对称，主要来自母本Z58，杂种优势强，苗期氮效率低。中丹958冠根的上级性状可能来源于父本昌7 -2。因此，Z58、长7 -2和两个野生玉米系（Z. parviglumisandZ. diploperennis）为氮高效和大根玉米育种提供了宝贵的种质资源。
Main conclusionZD958 was the most low-N-efficient line among five maize and two teosinte lines.Zea parviglumisandZeadiploperenniswere insensitive to N limitation. Maize and teosinte genetically and evolutionarily diverged in gene regulation. GDH2, ASN2, and T4 were consistently down-regulated across seven lines. Maternal asymmetric inheritance and heterosis vigor made ZD958 low-N-efficient.Nitrogen (N) deficiency remains a serious limiting factor for maize production in many developing countries. It is particularly important to better understand how hybrid maize responds to N limitation. ZD958, a dominant high-yield hybrid in North China, was comparatively analyzed with four other maize and two teosinte lines at physiological and transcriptional levels. ZD958 was the most low-N-efficient line among five maize and two teosinte lines due to its largest biomass accumulation at a lowest N concentration under N limitation; whileZea parviglumisandZea diploperennishad large root systems and were insensitive to N limitation. In anti-parallel with down-regulation of N metabolic genes in the ZD958 root, carbon allocation towards the root was enhanced for the significant increase in the root length. Variations in expression patterns of ten genes mediating N uptake, transport, and metabolism indicated large genetic and evolutionary divergence among seven lines under N limitation. Notably,GDH2,ASN2, andVAAT5were consistently down-regulated under N limitation across these maize and teosinte lines, suggesting essential evolutionary conservation of gene regulation in response to N limitation and providing molecular markers for N nutritional diagnosis. Asymmetric inheritance, mostly from its maternal donor Z58, and heterosis vigor made ZD958 low-N-efficient at the seedling stage. The superior traits in crown roots in ZD958 may be derived from its paternal donor Chang7-2. Thus, Z58, Chang7-2, and two wild maize lines (Z. parviglumisandZ. diploperennis) provide valuable germplasms for N-efficient and large-root maize breeding.